Draft Waipara River and Tributaries Environmental Flow Regimes
Report No. R07/10
White Gorge Flow recorder site looking upstream: Photo Herb Familton ECan, 14th March 2006.
ISBN 978-1-86937-639-0
MAY 2008
58 Kilmore Street 75 Church Street P O Box 345 P O Box 550 CHRISTCHURCH TIMARU Phone: (03) 365 3828 Phone: (03) 688 9069 Fax: (03) 365 3194 Fax: (03) 688 9067
Website: www.ecan.govt.nz Customer Services Phone 0800 324 636
Contents
1. Introduction ...... 1 1.1 Background...... 1 1.2 Important background information to aid understanding of this report ...... 1 1.3 Terms and Abbreviations...... 4 1.4 Allocation regimes/allocation blocks ...... 4 1.5 Description of the water resource units of the catchment...... 6 2. Hydrology and abstractions ...... 8 2.1 Background...... 8 2.2 Surface water...... 8 2.3 Waipara Surface and Groundwater System ...... 10 2.4 Flows to lagoon...... 11 2.5 Existing Upper Waipara abstractions...... 12 2.6 Existing Lower Waipara abstractions...... 14 2.7 Implications of the Tutton Sienko et. al. decision ...... 14 2.8 Viticulture ...... 15 2.9 Stream Depletion Effects ...... 16 2.10 Plantation Forestry and Willows ...... 16 2.11 Impact of water storage on catchment hydrology...... 17 2.12 Water storage potential...... 17 3. Upper Waipara instream values and their flow requirements...... 18 3.1 Indigenous fish - Objective WQN1(b) ...... 18 3.2 Indigenous riverbed birds - Objective WQN1(b)...... 18 3.3 Flows needed to provide for cultural values -Objective WQN1(c)(d)...... 18 3.4 Flows needed to provide for natural character, landscape values and natural features - Objective WQN1(f)...... 19 3.5 Trout and salmon -Objective WQN1(g) ...... 20 3.6 Flows needed to provide for amenity/recreation values (Objective WQN1 (h)...... 21 3.7 Flows needed to remove excessive periphyton, fine sediment, and invading woody weeds...... 22 3.8 Summary of flow requirements for instream values ...... 23 4. Reliability of supply for the Upper Waipara ...... 25 4.1 Importance of reliability of supply ...... 25 4.2 Assessment of the impact of restrictions for 1988 – 2005...... 25 4.3 Effect of restrictions: ...... 25 4.4 Reliability of Supply Upper Waipara and the frequency and duration of restrictions 26 5. Evaluation of minimum flow monitoring sites and options for the Upper Waipara ...... 30 5.1 Introduction ...... 30 5.2 Minimum flow monitoring site Upper Waipara mainstem ...... 30
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME i (NOT COUNCIL POLICY)
5.3 Comparative evaluation of minimum flow options (50L/s; 80L/s; 110L/s) against proposed NRRP Objective WQN1...... 30 5.4 Weighing of Weka Creek instream and out-of-stream values ...... 33 6. Allocation limits – Upper Waipara...... 34 6.1 A allocation blocks ...... 34 6.2 Cumulative effects of allocation ...... 34 6.3 Freshes and floods ...... 35 6.4 Upper Waipara A allocation block options...... 35 6.5 Upper Waipara B allocation block...... 39 6.6 C allocation block cut-off limits and block size for Upper Waipara mainstem ...... 40 6.7 Weka Creek allocation blocks...... 40 7. Lower Waipara instream values and their flow requirements...... 41 7.1 Lower Waipara River mainstem...... 41 7.2 Objective WQN1 values and flow requirements for Home Creek...... 43 7.3 Objective WQN1 values and flow requirements for Omihi Stream...... 44 8. Reliability of Supply for the Lower Waipara...... 45 9. Evaluation of monitoring sites and minimum flow options for the Lower Waipara ...... 47 9.1 Minimum flow monitoring sites...... 47 9.2 Evaluation of minimum flows ...... 47 10. Allocation Limits – Lower Waipara ...... 54 10.1 Lower Waipara Block Options ...... 54 10.2 Home Creek A and B blocks...... 55 10.3 Omihi Stream A and B Blocks ...... 56 11. Other matters ...... 57 11.1 Average daily take versus maximum rate of take...... 57 11.2 Phasing in of any new environmental flow and allocation regimes ...... 57 11.3 Flow sharing...... 58 11.4 Installation of water meters, data logging, and data transmission...... 58 12. Appendices...... 61 12.1 Appendix 1 - recommendations of the review...... 61 12.2 Appendix 2 - list of Waipara River Technical Reports ...... 64 12.3 Appendix 3 - effect on abstractors of proposed changes in flow regime for Lower Waipara River, Home Creek, and Omihi Stream...... 66 12.4 Assessment of the cost to abstractors of proposed changes to the flow management regime for the Waipara River below Omihi confluence ...... 74 12.4 Appendix 4 - Technical Panel field notes for Home Creek, Omihi Stream, and Weka Creek...... 78 12.5 Appendix 5 - Statutory Acknowledgement for Waipara River...... 86 12.6 Appendix 6 – attributes, technical information, and evaluation of main stem flow regime options ...... 88
II DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
12.7 Appendix 7 - White Gorge flow exceedance percentiles: October to April and May to September...... 98 12.8 Appendix 8 - Abstractions...... 103 12.9 Appendix 9 - Number of days of partial or full restriction for a 50, 80, 110 minimum flow and a 173 L/s allocation block...... 105
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME iii (NOT COUNCIL POLICY)
IV DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
1. Introduction
1.1 Background
The Waipara River is coming under increasing pressure for abstraction for irrigation as more of the area goes into high value crops, including grapes and olives. See figure 1 for an overview map of the catchment.
As a foothills catchment, the Waipara has low summer flows, and the existing surface water resource is highly allocated (Canterbury Strategic Water Study, 2002, p43). The groundwater resources are also at their sustainable limits (ECan, 2006, addendum to report LO5261/1), and opportunities for future summer water abstraction are certainly now limited. The Strategic Water Study (2002, page 93) noted that moderate storage in the Waipara was required to meet demand. Mosley (2002 p4) also noted that given current levels of allocation and reliability this…“would virtually force future abstractions to be for refilling storage, largely during the winter months”.
Further, some existing consents have expired and it is appropriate that replacement consents be considered in the context of the latest understanding of flow regime requirements. A consultation process was initiated with the community and an Advisory Group established to assist the Council with this process. This staff report reviews key areas of information relevant to this process and makes recommendations for revised environmental flow and allocation regimes. Any revised regime would become a formal variation to the Proposed Natural Resources Regional Plan (NRRP), and be inserted in Schedule WQN1 on approval.
1.2 Important background information to aid understanding of this report
1.2.1 Direction provided by Proposed Natural Resources Regional Plan Chapter 5 Water Quantity
Variation 1 of the NRRP guides the development of a flow management regime for the Waipara River and its tributaries. Chapter 5 of the NRRP sets out the objectives and policies that any new regime for the Waipara River and its tributaries will need to be consistent with. NRRP Objective WQN1 is of prime importance for setting flow regimes as it establishes the outcomes to be achieved. This objective is almost identical to that in the water chapter of the operative Canterbury Regional Policy Statement. NRRP Objective WQN 1 states:
“Enable present and future generations to access the region's surface and groundwater resources to gain cultural, social, recreational, economic and other benefits, while: (a) Safeguarding their existing value for efficiently providing sources of potable water for people and for stock; (b) Safeguarding the life-supporting capacity of the water, including its associated aquatic ecosystems, significant habitats of indigenous fauna, and areas of significant indigenous vegetation; (c) Safeguarding their mauri and existing value for providing mahinga kai for Ngai Tahu; (d) Protecting wahi tapu and other wahi taonga of value to Ngai Tahu; (e) Preserving the natural character of lakes and rivers and protecting them from inappropriate use and development; (f) Protecting outstanding natural features and landscapes from inappropriate use and development; (g) Protecting significant habitat of trout and salmon; and (h) Maintaining, and, where appropriate, enhancing amenity values.”
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 1 (NOT COUNCIL POLICY) (NOT COUNCIL POLICY) COUNCIL (NOT 2
DRAFT OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVER ANDTRIBUTARIES STAFFREPORT
Figure 1 Location of Flow Recorder Sites, 7DMALFS, and Existing Flow Monitoring Sites
Policy WQN3 in Chapter 5 the NRRP provides that:
“(1) For all water bodies where taking, using, damming, diverting or discharging of water occurs or is likely to occur, Environment Canterbury will progressively set flow or level regimes in Schedule WQN1 and Schedule WQN3 to meet the requirements of Objective WQN1, having regard to the matters listed in Policy WQN4, and also to meet the requirements of Chapter 4 – Water Quality Objective WQL1.1.
(2) Establish and maintain these flow and level regimes by:
a) controlling the taking, using, and diverting, or damming of surface water, and the discharge of water to surface water; b) controlling the effects of landuse on water yield inflow sensitive catchments (refer to Policies WQN6 and WQN7); c) controlling the taking and using of water from and individual bore or borefield where this causes a high or moderate stream depletion effect (refer Policy WQN8); d) limiting all groundwater abstractions which cumulatively reduce groundwater levels and thereby cause or are likely to cause a significant increase in the frequency, duration or severity of breaches of a minimum flow, or adversely affect the hydrology of a wetland (Refer Policy WQN9 and WQN14) e) not allowing abstraction of water to induce a river to go dry; and f) not allowing the taking, using, and diverting, or damming of surface water; or the discharge of water to surface water to result in a change to the water quality contrary to Chapter 4- Water Quality Objective WQL1.1.”
These regimes will be maintained by the means identified in Policy WQN3(2) (a) to (f). In addition, Policy WQN4 lists the matters to be considered in setting flow management regimes. Regard must also be given to any impacts that the regime proposed may have on meeting water quality objectives.
In achieving the cultural, social, recreational, economic and other benefits set out in Objective WQN1, the “while” parts of the objective, clauses (a) – (h), also have to be met for each water body. This involves a “weighing” exercise that takes into account the effects of a proposed flow regime on out-of-stream uses, such as irrigation. Issue WQN3 of the NRRP seeks to manage the effects of taking groundwater on surface water. Policy WQN8 outlines that ECan will manage stream depletion effects by assessing the degree of hydraulic connection on the surface water body. Where relevant, these stream depletion effects have been included in the flow regime and allocation assessments for water bodies in the Waipara catchment.
1.2.2 Other information
The suite of reports listed in 12.2, Appendix 2, provide much of the background information for understanding the mainstem of the Waipara River, particularly Reports R03/1, U02/84, U03/11, and U03/14. Other important sources include: the consents database; written reports/comment from scientists such as Jowett (2006), Gabites (2006), and Suren (2003); analysis of the hydrological record; information provided by abstractors; and information collected through compliance monitoring of consents over the 2003/04 summer. Chapter 12.3 and 12.4 of this report gives a range of estimates into the costs of mitigating the effects to the reliability of supply arising from the change in the minimum flow regime proposed in this report on reliability of supply.
The review of the minimum flows in the Waipara River tributaries has followed a separate process from the mainstem because less information was available. To gain the information needed to carry out the review, NIWA produced an aquatic ecosystems flow needs study (ECan report U04/107). A Technical Panel was also commissioned to provide expertise and advice on flow requirements for other Objective WQN1 values.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 3 (NOT COUNCIL POLICY)
1.3 Terms and Abbreviations A number of terms and abbreviations are used in this report. They include:
Environmental flow regime: means rules that manage and maintain the range of flows in a river. It always comprises an environmental minimum flow (hereafter referred to as the minimum flow) at which all but essential abstractions cease, and the regime can include other measures such as flow sharing, and caps on abstraction to protect the freshes and floods.
Minimum flow: means the flow at which abstractions from a water body must cease, other than for an individual’s reasonable domestic needs, the reasonable needs of individuals and animals for drinking water, and for fire fighting. Minimum flows set in a plan involve a “weighing” between the needs of out of stream users eg irrigators, and the need for the minimum flow to provide an adequate level of protection for the instream values set out in Objective WQN1 of Chapter 5 of the NRRP.
Allocation regime: means the provisions in a plan specifying the quantities and/or rates of flow of water available for abstraction above the minimum flow. Water available above the minimum will usually be divided into allocation blocks A, B, C etc Policies in NRRP Chapter 5 provide guidance on how allocation block sizes cajn be determined.
Allocation block: means a given amount of water, set as a flow rate that is available for abstraction, where all users allocated a proportion of that water will be subject to the same management controls.
Cut off limit: means the flow at which abstractions cease from the B allocation block.
Amenity values: mean those natural or physical qualities and characteristics of an area that contribute to people’s appreciation of its pleasantness, aesthetic coherence, and cultural and recreational attributes.
Seven day mean annual low flow (7DMALF): the 7DMALF is calculated by taking the seven consecutive days of lowest flow in each year of the flow record, adding them together, and then dividing the total by the number of years of flow record. Where there is long-term river flow data, there is a high level of confidence in the accuracy of the 7-day MALF. Where there is only limited data for a stream, mathematical correlation is made against a long-term recorder from another stream. For each 7-day MALF there may be a standard error shown by the symbol “±”. The ± indicates the flow range within which the 7DMALF is likely to occur 95% of the time, the larger the ± as a proportion of the 7DMALF figure, the less confidence there is in the 7DMALF.
L/s: Litres per second
Cumec (m3/s): Cubic metre per second (or 1,000 L/s)
1.4 Allocation regimes/allocation blocks
Allocation regimes are a useful tool for managing water demands because they help provide certainty to abstractors as to their reliability of supply, and can be used to avoid loss of flushing flows that are essential for maintenance of instream values. Determination of an allocation regime is therefore beneficial to all parties with an interest in the river.
4 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Calculating reliability of supply (also called security of supply) is best done when there is a long period of flow record. Not all rivers have this. The Waipara has a reasonable length of record for White Gorge, but considerably less for Teviotdale and the tributary streams.
Environment Canterbury uses the methodology set out in NRRP to identify an A allocation block with a reasonable reliability of supply. Policy WQN14 (4) states: “For a surface water body, when establishing an allocation block for Schedule WQN1, unless an alternative catchment specific approach is more appropriate, the size of the A allocation block shall be set so that all takes from that block have a level of reliability that will provide, on average: (a) the full allocation rate 95% or more of the time during the period mid October to mid March in 6 years out of 10; and (b) the full allocation rate 75% or more of the time during the period mid October to mid March in 9 years out of 10. “
The A or primary allocation block is the most reliable water available for allocation above the minimum flow. Allocation within it has to be limited to provide a reasonable reliability of supply to takes from within the block. As an analogy, imagine the A block is like a cake. The more people who share the cake, the smaller the slice for each person. Once the A block is fully allocated, no more permits can be granted from that block and additional water may be allocated from a B allocation block. However, it will have a lesser priority than the A block and takes will be required to cease abstraction at a higher flow (Figure 1). To meet increasing demand, the A block could also be made bigger to allow more people access to high priority water. While that can be good for the regional economy because the water is spread between more irrigators, the downside of a big A block with lots of permits (compared to a smaller A block with fewer permits) is that reliability of supply is reduced, meaning that on average, all takes will be restricted more often and get less water. A smaller A block has a higher reliability of supply. The downside of a small A block is that it only has a small number of permits in it so everyone else has to be in a B block with a lower reliability of supply. Blocks can be “stacked” on top of each other, or gaps can be left between them. Gaps can help prevent “flat-lining” of river flows, i.e. abstractions drawing the flows down to the minimum flow for long periods.
C Block for abstraction
Gap C block cut-off limit
B Block for abstraction
Gap B block cut-off limit
A block for abstraction A block minimum flow
Flow for instream values
Figure 2: Water Allocation, A, B and C blocks
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 5 (NOT COUNCIL POLICY)
Chapter 5 Policy WQN14 also indicates a preference for the A block to be determined on the basis of the average daily rates of take, because it results in a smaller A block with a higher reliability. It also makes for more efficient allocation. However there are some practical difficulties with this, especially on smaller rivers with a small number of takes, or where there are groundwater takes having stream depletion effects. As an example, consider two takes, one of 80 L/s and the other of 20 L/s, the average would be 50 L/s. If the A block was 50 L/s but the consent holder actually needed 80 L/s to make their irrigation system work, their rate of take would exceed the top of the A block. Therefore in these situations, it is preferable to determine the size of the A allocation block by adding the maximum rate of take (max rate) of each surface water permit as many irrigation systems can only operate at their maximum rate.
1.5 Description of the water resource units of the catchment
The Waipara Catchment consists of six separate water resource units (see figure 3). For environmental flow and allocation regime management purposes, they are combined into an Upper Waipara group and a Lower Waipara group. The description of each is as follows:
(a) Upper Waipara This group consists of: • The Waipara River mainstem from its headwaters to just above the Omihi confluence, including all its tributaries above the White Gorge Flow recorder; • Boby Stream; • Weka Creek; and • All the groundwater zone that is hydraulically connected to these waters.
(b) Lower Waipara This group consists of: • The Waipara River mainstem below the Omihi Stream, including all the tributaries; • Home Creek and its tributaries above its confluence with Omihi stream, • Omihi Stream and its tributaries, excluding Home Creek; and • All the groundwater zone that is hydraulically connected to these waters.
6 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
(NOT COUNCIL POLICY) (NOT COUNCIL AND TRIBUTARIES REPORT ON WAIPARA RIVER DRAFT STAFF
PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED
Figure 3: Water resources of the Waipara Catchment 7
2. Hydrology and abstractions
2.1 Background
The Waipara River drains a small North Canterbury foothills catchment encompassing an area of approximately 726 square kilometres. It is located towards the northern end of the Canterbury plains, extending some 40 kilometres from the Double Tops Range in the west to the Waipara Lagoon in the east. The Waipara Lagoon is intermittently open to Pegasus Bay in times of fresh flows (flows greater than eight cumecs), largely in winter and spring.
The North Branch flows initially eastward from hill country and then flows southward across Masons Flat. The Middle and South Branches join below Masons Flat, and the mainstem then flows eastward through the Ohuriawa / White Gorge. Boby Stream enters just below the White Gorge water recorder, see figure 3.
Below White Gorge, the mainstem continues flowing eastward across the large alluvial basin of the Waipara flats. Weka Creek flows into the mainstem approximately ten kilometres downstream of Ohuriawa / White Gorge. A dam is located at the southern end of Weka Pass. Below the Weka dam, Weka Creek opens out into a wide shingle bedded river between high terraces. About four kilometres below the dam, the surface flow disappears into the gravels and there is no surface flow at the confluence of the Weka Creek and Waipara River, other than in flood times. The 7DMALF of Weka stream at the Waipara mainstem confluence is therefore zero.
The predominantly stream-fed Omihi Stream flows in a south westerly direction at the south- eastern end of the Waipara flats. In its upper reach at Baxters Road Bridge it is often dry in summer. Further down at the Vineyard Bridge it consists of a series of deep pools in open grassland bordered by vineyards. Where the Omihi flows into the Waipara River, the river bed is shingle and the stream is shaded by willow and broom. The Omihi Stream can therefore be described as a very slow flowing meandering stream connecting a series of often deep pools. Groundwater springs contribute significantly to the flow in the lower Omihi Stream. The deep pools provide refuge for aquatic species during the low or no flow periods.
Home Creek flows into the Omihi Stream prior to entering the Waipara just below SH1. It is a very slow flowing ponded water body interspersed with minor slow flowing riffles, thick willows on the margins and considerable pond weed. In some reaches it flows through open pasture and some reaches are dry in summer. The bed of Home Creek is mostly gravel and the water is clear. The upper reaches appear to have higher flow than the lower reaches. While Home Creek dries up in places, mainly in summer, the pools remain as refuges for aquatic flora and fauna.
Below the Omihi confluence, the Waipara River cuts through the coastal hills at Teviotdale Gorge, before exiting out and flowing across a narrow coastal plain to the Waipara Lagoon at the coast.
2.2 Surface water
There are hydrological differences between the upper and lower parts of the Waipara River. The Upper Waipara is foothill-fed, which means that water flow and yields are generally low in the late summer due to reduced rainfall. This also means that the catchment does capture significant amounts of southerly and easterly rainfall, particularly in the winter months.
The Lower Waipara has higher and more consistent flow due to the inputs from the spring- fed Omihi Stream, and from groundwater resurfacing as the bed narrows through the gorge to Teviotdale. Downstream of Teviotdale large losses occur from the river to groundwater, to the extent that the last couple of kilometres upstream of the lagoon are often dry in late summer. Because allocation of water to abstraction from Omihi Stream will strongly
8 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
influence flow in the lower Waipara, it is appropriate for allocation purposes for Omihi Stream and the lower Waipara to be managed as one unit.
There is a good length of hydrological record for White Gorge (established 1988) but a much shorter record for the Teviotdale recorder in the lower Waipara. It was only established in 2000. However, since 2000 the river has experienced some severe drought conditions so the site has provided flow data that is very useful for setting flow regimes. Most data quoted for the Waipara will refer to the White Gorge flow recorder site because of its longer record.
The mean annual or average flow for the river at White Gorge is 2,750 L/s, median flow (flow occurring 50% of the time) is 890 L/s, and the 7DMALF is 110 L/s (Chater 2002). Over the flow record and for all months, the river at White Gorge is above 2650 L/s 25% of the time and below 323 L/s 25% of the time (ECan 2007 data).
However, in the summer irrigation season, (October to April) the river is below 165 L/s 25% of the time and above 1177 L/s 25% of the time. (See Chater 2002, tables 3.1 and 3.2). The lowest recorded flow at White Gorge was 25 L/s recorded on 19th February 1998. This was during a drought with a return period of 1:130 (Horrell et. al, 1998). The flow distribution curve of the river at White Gorge is outlined in Figure 4.
5000 Mean flow
4000
3000
2000
1000
0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Fraction of time flow is not exceeded site 65901 Waipara at White Gorge Flow l/s 25-Feb-1988 10:00:00 to 3-Oct-2007 08:30:00
Figure 4: Flow Distribution Graph White Gorge all Months (Source: Chater 2002)
The monthly flows in Table 1 for the Waipara clearly show a hill country pattern of high flows over the July to October period, with lower flows in the January to April periods.
Table 1: Maximum, mean and lowest monthly flows (L/s) at White Gorge 1989- 2007 (Source ECan Archive) Flow Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Min. 49 28 58 70 278 312 797 598 543 875 337 113 Mean 1506 542 583 837 1369 3051 5628 5875 5050 3521 2244 1683 Max. 19444 3216 4756 4066 2965 9339 17179 20868 19506 10153 8040 14697
Modifications to the natural hydrology can arise from abstractions, dams, diversions, and water storages. The naturalised 7DMALFs provide a useful way of comparing what the flow would have been at various points in a river, in the absence of abstractions. Table 2 shows the 7DMALFs at a number of locations, from White Gorge downstream.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 9 (NOT COUNCIL POLICY)
Table 2: Waipara River 7DMALFs at specific sites
SITE 7DMALF L/S COMMENTS (SOURCE DATE) White Gorge 110 Site of telemetered water flow recorder in mid (Scarf 2007) Catchment. (Data currently not effected by abstractions) Boby Stream 20 Tributary just below White Gorge (Scarf 2007) Just above Omihi confluence 129 From White Gorge to Omihi confluence the (Scarf 2007) river loses flow in some places and gains flow at others. Just below Omihi confluence 276 Flow gaining from Omihi Stream inflow (Scarf 2007) Teviotdale 300 Generally flow gaining reach from Omihi (Scarf 2007) confluence to Teviotdale Greenwoods Bridge 235 From Teviotdale to coast flow is lost into the (Chater 2003) permeable riverbed gravels
Until recently the flows at and above White Gorge have been natural flows, because abstractions in the mainstem of the Waipara River were down stream of White Gorge. However, consents for a series of dams upstream of White Gorge , the Scott, Greys Rd, and Fenlon dams (CRC 063390, 063393, and 063396) were granted by ECan in October 2006. These dams can store a total of 227,500 litres, but have not yet been constructed.
Boby Stream enters the mid-Waipara just below the White Gorge water level recorder and contributes an estimated 7DMALF of 19 L/s when the flow at White Gorge is 112 L/s. It is the only significant tributary of the Waipara River below White Gorge not currently subject to any consented abstraction. The Weka Creek does not contribute any flow during 7DMALF periods.
Table 2 indicates that the combined 7DMALF flows for White Gorge and Boby Stream total 130 L/s, very close to the 7DMALF flow just above the Omihi confluence. This relationship holds down to about 80 L/s at White Gorge.
In February 1998, the river nearly went dry just above the Omihi confluence (Chater 2002). Water restrictions were in force at that time so the low flow was not being induced by abstraction.
2.3 Waipara Surface and Groundwater System
Table 3 sets out the the inflows into the catchment and discharge out of the Waipara catchment (Scarf 2007, Gabites 2006). It shows that generally there is a balance between the inflows of the Waipara mainstem and the estimated outflows at the site above the confluence with the Omihi Stream.
The total “input” mean annual flow of the Waipara below the Omihi confluence of 3805 L/s is very close to the “output” mean annual flow of 4000 L/s at Teviotdale, indicating that there is no net-loss to groundwater from the Waipara River or it’s tributaries between White Gorge and Teviotdale. In contrast, below Teviotdale there is a significant loss of surface water to the underlying gravels as the river crosses a narrow coastal plain before flowing into the Waipara Lagoon. This loss, however, cannot be considered available for groundwater allocation within the greater Waipara basin because it is geographically separated from it.
The outflow from the Omihi Stream to the Waipara is greater than its inflows of surface water, suggesting a contribution from groundwater that is separate from the surface water resource of the Omihi. Large springs in the lower Omihi may well be the outlet for this additional groundwater flow although the source of the additional water has yet to be confirmed. This suggests caution is needed with the extent of additional abstraction from groundwater from the Waipara basin, in case it affects these springs. This is important given that summer flow in the lower Waipara is so dependent on Omihi flow.
10 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Table 3: Input/Output flows for the Waipara River and tributaries (Based on Gabites 2006 and Scarf 2007) 7DMALF Mean flow Estimated as an annual Area Mean as % of Estimated Mean volume above Annual Flow (millions of site 7DMALF (Litres / Annual cubic (km2) (Litres / second) second) Flow metres/year) Inputs to Waipara Mainstem Waipara at White Gorge 370 110 2790 3.0 102 Weka Creek below Irrigation Diversion 56 5 300 1.7 9.5 Boby Stream 25 20 170 11.8 6.2 Waipara catchment below White Gorge - outside Weka and Bobys1 67 0 200 0.0 6.3 Input Waipara totals 518 129 3280 120
Inputs to Omihi catchment Omihi Stream at Baxters Road 97 0 100 0.0 3 Home Creek at Kings Road 34 22 100 22 4 Omihi catchment - outside Home and below Baxters Road1 47 0 50 0.0 2 Input Omihi totals 178 22 250 9
Omihi at Waipara Conf 178 147 525 28 19.2 Waipara at Omihi Conf 518 129 3280 3.9 120
Total input flow below Omihi Confluence 696 276 3805 139
Outputs Waipara at Teviotdale2 (2006 data included) 710 300 4000 13 146 1Yield for specific areas calculated using ECan’s mean and 7DMALF isohyetal maps 2 Waipara at Teviotdale estimates include data to March 06
2.4 Flows to lagoon
Chater (2002) and Lloyd (2002) identify a rapid reduction in river flow downstream of the Teviotdale recorder, including reference to the river going dry below Greenwoods Bridge. Greenwoods Bridge is approximately 3km downstream of the Teviotdale flow recorder site.
Gaugings done in January, February, and April 2006 confirm Greenwoods Bridge is in a flow losing section of the river. The losses are not attributable to abstractions between Teviotdale and Greenwoods Bridge, as none occur in this reach. All three gaugings showed flow losses in the order of 10-20% at Greenwoods Bridge. The results were as follows:
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Table 4: Concurrent gaugings showing losses between Teviotdale and Greenwoods Bridge
Gauging date Teviotdale flow (L/s) Greenwoods Flow (L/s) Flow loss (L/s) 06/01/06 351 312 39 06/02/06 281 226 55 14/04/06 474 429 45
The discrepancy between the 7DMALF’s and the above gaugings, when comparing Teviotdale and Greenwoods Bridge sites, may be attributable to seasonal variations in groundwater levels (pers. comm. ECan hydrology staff). Chater (2002) also did concurrent gaugings during January, February and April 2001 and recorded similar losses between Teviotdale recorder and Greenwoods Bridge.
It is clear that if the flow at Teviotdale fell to 110 L/s the length of dry riverbed would most likely be significantly longer than occurs in most summers. Increased abstraction below Teviotdale would make this worse.
At the time that the ECan gauging was undertaken on 06/01/06, even with a flow of 351 L/s at Teviotdale, the river was not flowing to the lagoon. ECan’s current understanding is that a flow of between 400-600 L/s at the Teviotdale recorder is needed to provide a continuous flow to the lagoon.
2.5 Existing Upper Waipara abstractions
The current takes from the Waipara River and its tributaries are summarised in Appendix 8. Most consents are for irrigation takes, but a number are for takes to winter storage, and some for frost-fighting in the winter/early spring. The conditions on consents often express the water take as a take all year, yet the consent may only be used for a part of the year. This can create a misleading indication of real time water use and could lead to inefficient, unreliable, and inequitable water allocation. However, the most critical time for an irrigation abstraction is the summer period of October to April.
No consents have conditions requiring their rate of take to be progressively reduced as the available flow above the minimum reduces. This requirement is sometimes referred to as pro-rata restrictions or partial restrictions. The absence of such a condition can lead to flows being reduced below the minimum, particularly when the abstractions are downstream of the minimum flow reference site.
As at 1 April 2008 the summer maximum rate of abstraction of consented surface water and hydraulically connected groundwater from the mainstem is 244 L/s, comprising 180 L/s (rounded up) for the Upper Waipara and 64 L/s Lower Waipara. Applications for a further 572 L/s await decisions (248 L/s for the Upper Waipara, 260 L/s for the Weka and 64 L/s for Omihi Stream).
To help protect instream values, all consents to abstract from surface water, and hydraulically connected groundwater where it causes a significant stream depletion effect, require a minimum flow condition. The stream depletion effects were calculated using NRRP Chapter 5 Policy WQN8 on each relevant bore at a 150 day pumping rate using the Jenkins methodology.
The mainstem low flows, abstraction and storage are represented in Figure 5 below.
12 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Figure 5: Summer Waipara Water Allocation, Storage, and 7DMALF
As at 1 April 2008, there are a total of 12 consented surface water takes and six hydraulically connected groundwater takes from the mainstem of the Upper Waipara River. It is noted that: • the total consented peak instantaneous rate for surface water takes and hydraulically connected groundwater is 180 L/s in the summer; • when averaged over 24 hours, the consented rate of surface water takes is about 160 L/s; • the maximum peak rate of take of surface water is 281 L/s in winter; • the measured rate of take, based on monitoring of abstractions over the 2003/04 summer, is 85 L/s (for consents issued and being used at this time). (See table 21) • the combined measured rate of take averaged over 24 hours was less than 60 L/s (3 minor groundwater takes were not measured, but would make little difference to the result); • the calculated stream depletion from hydraulically connected bores using NRRP policy WQN8 is 39 L/s; • applications for a further 210 L/s have yet to be processed.
Six consents with minimum flows are referenced to White Gorge and four are referenced to Stringers Bridge. None of the hydraulically connected groundwater consents have minimum flow conditions.
For Weka Creek, there is one consent to divert 1020 L/s and one surface water take of 820 L/s (70,848m3/day). The dam diverts water from Weka Creek just before it reaches the Omihi Valley floor into an irrigation system on the true left bank of the Waipara. Races convey the water to a series of dams. The first 28 L/s of flow is required to bypass the diversion dam for stock watering purposes, but surface flow is only sustained for about 4 kilometres below the dam and thereafter there is no summer surface flow down to the confluence of the Waipara River. Flows between 28 L/s and 1020 L/s are diverted into the Weka Creek irrigation scheme. Flows above 1020 L/s spill over the dam and down Weka Creek. Weka Creek subsurface flow helps to sustain surface flows in the Waipara River.
The mean flow of Weka Creek is only approximately 650 L/s (Chater 2002), so for much of the time the whole of the consented rate of take is unavailable, and freshes and floods are harvested for storage. Weka Creek Ltd have applied for a new consent for a divert and take of 1020 L/s but to discharge by wash water at 200 L/s. The new application essentially maintains the status quo.
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2.6 Existing Lower Waipara abstractions
As at 1 April 2008, there are two consented takes for the Lower Waipara River. It is noted that:
• The total consented peak instantaneous rate of take for irrigation is 64 L/s; • When averaged over 24 hours, it is about 48 L/s; • The total consented peak instantaneous rate of take for frost-fighting May to November is 45 L/s; • The minimum flow site is the Teviotdale water level recorder which is located below the Donaldson take (28 L/s) and above the take for Croft (36 L/s).
Donaldson’s take is just below the Omihi Stream confluence, but upstream of the Teviotdale recorder, and is for 28 L/s in the summer for grape irrigation and 45 L/s for frost-fighting August to November. Croft’s gallery take is below Greenwoods Bridge (downstream of the Teviotdale recorder). While Croft’s consent allows the abstraction of 36 L/s, their current pumping capacity is only 19 L/s (measured by ECan 2006).
As at 1 April 2009, there are three surface water consents and three hydraulically connected groundwater consents for Omihi Stream. A total of 64 L/s can be taken. One consent (CRC011937) has a minimum flow site at Baxters Road Bridge and one consent (032147) has a minimum flow site at the Omihi confluence The other small surface water consent (1.4 L/s) does not have a minimum flow. A further three applications to take 66 L/s are pending. None of the hydraulically connected groundwater consents have minimum flow conditions.
As at 1 April 2008, there are three surface water permits to take a total of 110 L/s from Home Creek. Of this, 95 L/s is taken in the winter to storage and the remaining 15 L/s is used for irrigation.
2.7 Implications of the Tutton Sienko et. al. decision
This Planning Tribunal case (W100/95) concerned an application to take water from either the mid Waipara River or an excavated pond, at 38 L/s and up to 3283 cubic metres per day. The purpose of the proposal was to create storage for trickle irrigation of grapes or other horticultural crops. The 200,000 litre storage pond was to provide a buffer of 55 days of irrigation.
This consent was appealed by Tutton Sienko and Hill, Johns, and Donaldson, for reasons including:
• That Maungatahi Farm Ltd already had an adequate supply for irrigation water; • Loss of reliability of supply; • That the Waipara River was over-allocated; and • That it did not promote sustainable management of the Waipara River
The Planning Tribunal heard, and agreed with, evidence about impacts on the reliability of supply of existing abstractors, particularly Donaldson, and that significant stream depletion effects would occur with this proposal, even though the pond was 500 metres from the river. The Tribunal granted the consent at the 38 L/s rate subject to certain conditions, including: • Storage of 200000 litres must be a condition of the consent, although storage could be developed in stages consistent with the proportion of the 142 hectares developed • The take should be proportional to the area developed • A development plan to give effect to this condition was required; and • A sliding scale of abstraction such that when the White Gorge flow is below 199 L/s, then all water abstracted must be from the pond 500metres from the river, and when below 161 L/s, all abstraction from the excavated pond shall cease.
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As at 1 April 2008 the Maungatahi Farm Ltd consent proposal has not been granted by Ecan because the development plan matters have not yet been finalised.
The major implication of this decision is that consents issued after 1995 should be B permits to protect the reliability of existing abstractors, and that storage should be a necessary part of future applications to provide an adequate summer reliability of supply.
2.8 Viticulture
The Waipara region has experienced considerable growth in viticulture and horticulture over the last twenty years, due to its favourable combination of warm sunny micro climate, isolation from the Canterbury easterly, and favourable limestone and alluvial soils. The area is now internationally recognised as a significant producer of quality wines and horticultural crops such as olives, and this has made a significant contributor to the local economy and employment.
The significance of the wine growing potential of the Waipara region was recognised in the Environment Court case of Waipara Wine Growers Inc. v Hurunui DC (C218/99). In this case, the special characteristics of grape growing in the Waipara area were recognised by a specific District Plan zoning and rules in the Hurunui District Plan.
The growth in land use devoted to grape growing, has increased the demand for irrigation water, particularly over the peak of the summer season. Vineyards are generally very efficient users of water as drip irrigation systems are commonly used.
Marlborough research (Marlborough Crop Water Use Efficiency Report, Green et. al. 2005) has shown than traditional vineyard water allocations are conservative. This means that there may be efficiency gains in water allocations when consents are reviewed under the reasonable use test set out in NRRP Policy WQN17. Water savings of between 40-51% are potentially available if targeted strategies such as regulated deficit irrigation (RDI) are applied. RDI techniques can be utilised by growers to impose a managed water deficit in the upper soil layer to optimise fruit yield and quality. This amount can be as little as 2 mm per day over the summer season. In many cases, vineyards are reviewing their soil moisture content on a weekly basis using specialist climatological advice to ensure just the right amount of water necessary for healthy production is applied.
Young vines will tend to concentrate their roots in the irrigation zone in the early stages of their development. As vines grow, their roots penetrate deeper and wider. Young vines are therefore more susceptible than older vines to prolonged periods without water. If irrigation is inadequate at certain times of the year, it will affect fruit yield and quality. If cessation is prolonged, it can kill young vines, and/or the stress can cause poor bud/flower production in the subsequent season. In the worst case, even mature vines may die. Because vines take five years to come into production, if they die, there is a period of five years of no income, plus the cost of re-establishing vines.
The key constraint for viticulture and horticulture in the Waipara area is low water availability in summer. Storage of water during the winter-spring high flow period is one management tool to deal with this risk, and these opportunities are discussed in chapter 2.11.
Some vineyards are supplied by the Glenmark (Weka) Irrigation scheme which encompasses several storage dams to the north side of the Waipara River, using captured flows from Weka Creek. Many vineyards outside the scheme have built on farm storage because run of river irrigation from the Waipara is inherently unreliable, especially in the late summer in the reach between White Gorge and the Omihi confluence.
Because of the reliable inflows from the Omihi Stream and resurfacing groundwater, reliability in the lower Omihi Stream and lower Waipara is very high. However, reliability in the lower Waipara will be reduced by additional abstraction from Omihi Stream, therefore they need to be managed as one unit for allocation purposes
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2.9 Stream Depletion Effects
The management of groundwater abstract and its impacts on surface water bodies is addressed by NRRP Policy WQN8 1(b), which states that any takes from bores or borefields classified as having:
• a high degree of connection will be managed the same as a surface water take for flow and allocation purposes as per policies WQN14 and WQN19 (that is, it will be subject to a minimum flow and accounted for in the applicable surface water allocation block);
• a moderate degree of hydraulic connection will have the stream depletion effect determined as the effect after 150 days of pumping at the continuous rate required to deliver the seasonal volume. This stream depletion effect shall be counted as part of any applicable surface water body allocation block (refer Policy WQN14). Where the stream depletion effect exceeds either the stream depletion cut-off limit set in Schedule WQN1, or where none has been set in Schedule WQN1, five litres per second, the take shall be subject to the minimum flow regime, and to restrictions in accordance with Policy WQN19); and
• a low degree of hydraulic connection will have the depletion effect determined as the effect after 150 days of pumping at the continuous rate required to deliver the seasonal volume. Where the stream depletion effect exceeds either the stream depletion cut-off limit set in Schedule WQN1, or where none has been set in Schedule WQN1, five litres per second, This stream depletion effect shall be counted as part of any applicable surface water body allocation block as per Policy WQN14
Stream depletion effects have been calculated and they are shown in Appendix 8. They have been included in the relevant allocation block in this report to give effect to Policy WQN8.
2.10 Plantation Forestry and Willows
Changing from short to tall vegetation, for example from grassland to forest, can have a significant effect on low flows in some Canterbury hill catchments, including the Waipara. Such vegetation cover changes can increase the severity, duration and frequency of low flows and impact on instream values and the reliability of supply to existing abstractors. Unlike abstractions, the effect of such afforestation cannot be turned off. Therefore excessive expansion of forestry in the Waipara could have significant impacts on existing irrigators.
Duncan (2007) has assessed the likely effects willows could have on river flows. If short grassland was to replace a riparian corridor of willows 70 kilometres by 50 metres, the gains in flow would be approximately 114 L/s (a flow similar to the 7DMALF at White Gorge). Mosley also commented that the effect of willows on river flows was equivalent to approximately 26 L/s of instantaneous abstraction.
Horrell (2007) outlines a worst case scenario with regards to reliability loss by the afforestation of the Upper Waipara catchment. If the entire catchment was planted in exotic forest, restriction days would have increased from 71 to 103 days if the minimum flow was set at the 7DMALF.The effect is especially significant in dry years such as 1988/89, but reliability losses for down stream irrigators will still be felt in average irrigation seasons. While this does not impact on the choice of environmental flow regime, it does highlight the vulnerability of the Waipara and the need to manage such land use changes.
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NRRP Policy WQN6 seeks to manage increases in plantation forestry. For the Waipara, up to ten percent of any forestry unit can be planted as a permitted activity. Planting more than ten percent of a forestry unit requires a land-use consent from ECan.
2.11 Impact of water storage on catchment hydrology
Table 5 indicates that the combined capacity of all the existing dams in the Waipara catchment is only equivalent to 0.5% of the annual water yield past the Teviotdale water level recorder.
Table 5: Water Yield and Dam Water Storage Capacity
Mean annual Storage capacity water yield (cubic (cubic metres) metres/year) White Gorge 110 000 000 Upper Waipara 249,000 Weka Creek 20 000 000 Weka Creek 212000 Omihi Stream 17 000 000 Omihi Stream 206000 Home Creek 199000 Mainly groundwater 9 000 000 Teviotdale 156 000 000 Total dam storage for 866,500 Waipara catchment Current Storage as a % 0.5% of water yield at Teviotdale
The dams on the Weka are equivalent to only 1% of the Weka Creek annual water yield. While the dams are normally filled in the winter and the flow utilised through the irrigation season, they can be topped up when flows are higher through the irrigation season. The Weka scheme irrigates up to 840ha, with a maximum take consented at 820 L/s and a maximum consented volume per day of 70, 848 cumecs per day. A by-pass structure upstream of the dam ensures that a minimum flow of 28 L/s is retained downstream.
The diversions to storage have a very small impact on catchment hydrology and store only a small portion of the flow that would have flowed down the river. Some of this stored water is lost through dam leakage and irrigation losses and may have a small, but probably insignificant benefit to the groundwater system and to low flows in the Waipara River. The consents for the Scott, Greys Rd, and Fenlon dams in the Upper Waipara should not have an adverse effect on the hydrology at times of low flow as their catchments do not contribute flow when flow at White Gorge is at or below the 7DMALF.
This cumulative effect of takes to storage is best managed by ensuring that they occur at higher flows but do not affect the frequency and magnitude of flushing flows and floods.
2.12 Water storage potential
The greatest opportunity for harvest occurs in winter and spring when flow is higher. Summer freshes are infrequent and often of short duration, which will limit the opportunity to replenish empty dams. Therefore, new storage structures need to be of sufficient size to capture most of the irrigation season demand from winter flows, and not have to rely heavily on summer freshes to top up. Opportunities for new storage structures may be limited by suitable take off, storage and dam sites, and physical access for conveyance. The costs of building storage structures and the associated infrastructure (pumps, pipelines, power supplies, etc.) are discussed in Appendix 3.
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3. Upper Waipara instream values and their flow requirements
Appendix 4 and Appendix 6 lists all the relevant available flow-related information for the instream values of the Upper Waipara River and Weka Creek, along with the flow requirements for each of the relevant values in Objective WQN1. Objective WQN1 (a), potable water supply, is not relevant to the Upper Waipara
3.1 Indigenous fish - Objective WQN1(b)
Jowett (2006) suggests that a flow of 80 L/s would be sufficient to sustain the life-supporting capacity of the Upper Waipara mainstem for the following indigenous fish: Canterbury galaxiid, upland bully, and longfin eel. His assessment was that a flow of 80 L/s would result in a habitat loss of 5-7% and that this level of loss would not have any significant effect on the fish population. A flow of 80 L/s at White Gorge when combined with the flow from Boby’s Stream (19 L/s), should be sufficient to avoid creating ideal conditions for periphyton blooms, thereby helping to maintain the life-supporting capacity for indigenous fish.
In the winter and spring, it is important that abstractions do not reduce the occurrence of freshes of 8 – 10 cumecs, so that the lagoon is open to the sea for the migration of native fish.
NIWA electric-fished the Weka Creek just below the Weka Dam and recorded the presence of upland bully, longfin and shortfin eels. They classified Weka Creek amongst the moderate flowing group of streams and recommend that the minimum flow be based on the habitat preference for juvenile brown trout rearing. This should also protect the flow requirements of the native fish species present. They recommended 8 L/s would suffice.
3.2 Indigenous riverbed birds - Objective WQN1(b)
The mainstem of the Waipara commonly provides habitat for the following threatened indigenous bird species: banded dotterell, wrybill plover, and black-fronted tern, each of which prefers to nest in vegetation-free gravel areas. It also provides habitat for other more common riverbed birds such as gull species. Some birds feed primarily on small native fish while others feed in shallow water or on the wet margins on aquatic invertebrate insects living on or under stones. Breeding mostly occurs between August and January. Scientists think that having a good flow in the braided channels is important as a barrier to predators. However in a small braided river like the Waipara, braiding reduces the flow in each channel which in turn may reduce the effectiveness of flow as a barrier. Recent research has suggested that the effects of predation by other birds, e.g. gulls, may also be important, but no specific information is available for the Waipara River. Higher flows also increase braid numbers and create more shallow areas for birds feeding on aquatic insect larvae. No specific study has been done for the Waipara to guide minimum flow decisions for riverbed birds. However, flows are naturally higher during the August to December period and therefore, even with abstractions, are likely to provide adequate flows for invertebrate production.
Encroachment of exotic weeds onto the gravels is a major threat to the habitat of riverbed birds. Protection of larger floods from the effects of mainstem dams will be necessary for maintaining a natural mechanism for removing these weeds.
3.3 Flows needed to provide for cultural values -Objective WQN1(c)(d)
The Waipara River is identified as a Statutory Acknowledgement in the Ngai Tahu Claims Settlement Act 1998 and therefore is a river of particular significance to Ngai Tahu. The
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Statutory Acknowledgement states “ The tupuna had considerable knowledge of whakapapa, traditional trails and tauranga waka, places for gathering kai and other taonga, ways in which the use of the resources of the river, the relationship of people with the river and their dependence on it, and tikanga for the proper and sustainable utilisation of resources. All of these values remain important to Ngai Tahu today”.
The Settlement Act identifies taonga (treasured) species, some of which can be present in the Waipara River, including: inanga, paraki (common smelt), torrent fish (piripiripohatu), kokupu, blue gilled bully, and pataki (flounder). Lamprey and long and short finned eels are also present, and are a source of Mahinga kai for Ngai Tahu. It is likely that the flow requirements for indigenous fish identified by Jowett (2006) will provide an adequate level of protection for these taonga species.
The term “mauri” has been identified as a key element to consider when setting flow regimes for rivers. It is an important concept within Ngai Tahu resource management, as it is for Maori generally. While not precisely definable in terms of western science, attempts have been made to identify tangible elements. The Te Runanga o Ngai Tahu Freshwater Policy also identifies general elements of mauri. For the Waipara River, it is likely to include such things as source-to-sea continuity of flow, the maintenance of natural patterns of flow, the river physically looking, sounding and smelling like a healthy braided river, the naturalness of the river and its bed, the life-supporting capacity of the river, including the presence of birds, and healthy Mahinga kai species, e.g. tuna/eels.
Zygadlo-Kanara and Te Runanga o Ngai Tuahuriri (ECan report U04/01), identified measurable elements of the Waipara’s mauri and how that related to ECan’s river monitoring. That report identified that the existing minimum flow of 60 L/s at Stringer’s Bridge is not adequate to protect the natural pattern of low flows.
For Weka Creek, Ngai Tuahuriri Runanga noted that the general appearance at Weka Dam was good and that the aquatic ecosystem appeared to be in good health. No recommendation as to the flow requirements was given.
3.4 Flows needed to provide for natural character, landscape values and natural features - Objective WQN1(f)
The Hurunui District Plan has identified an area immediately above White Gorge that has outstanding landscape values and significant natural sites relating to the geology of the area. Protecting these values is not dependant on the minimum flow and allocation regimes that are the primary focus of this report. However, those in or close to the bed could be affected if a mainstem dam was built in White Gorge. Below White Gorge, the river widens and takes the form of a braided river, running between low terraces. The bed margin is primarily willow- lined, and willows and other exotic plants in places have colonised the riverbed.
Mosley (2003) considers the reach from White Gorge to SH1 has low to moderate scenic qualities, a valuation that probably holds down to the Omihi Stream confluence. The presence of a continuous flow of water that looks, smells, and sounds like a healthy river is a fundamental part of the mauri and natural character of any river. Low flows can diminish the mauri and natural character of the river. It is likely that the flow required for limiting periphyton growth, 100 L/s, will provide minimum adequate conditions for these values.
For Weka Creek, McManaway noted that the flow at the dam was sufficient to sustain natural character/amenity values, but that the river deteriorated further down, where she describes the amenity values as low. She recommended a minimum flow of 28 L/s would protect natural character and amenity values.
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3.5 Trout and salmon -Objective WQN1(g)
The mainstem of the Waipara River does not provide habitat for salmon because the lagoon is closed most of the time late in the summer, the river has high water temperatures and insufficient depth for salmon passage. Therefore, for subsequent analysis in this report, salmon are excluded from evaluation for the Waipara River.
The Waipara River, particularly below White Gorge, does not provide significant habitat for trout and is regarded as a trout fishery of only local importance. Limited trout fishing does occur, generally upstream of the reach that extends from White Gorge to the Omihi Stream confluence. Because habitat conditions frequently become unfavourable in this reach, trout are likely to move downstream into the Lower Waipara or upstream into the river above White Gorge to avoid high water temperatures. Temperatures in the middle reach of the Waipara have been measured at 25 degrees centigrade in summertime, which are lethal for salmonids (Mosley 2002). See Figure 6 below.
30
25
20
15
10
Water temperature (degrees C) 5
0 15- 16- 17- 18- 19- 20- 21- 22- 23- 24- 25- 26- 27- 28- 29- 30- 31- Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan Jan
Figure 6: Stringers Road Water Temperatures: 15-31 January 2000 (Mosley 2002)
NIWA has established that, in general, for smaller rivers, the 7DMALF coincides with a lower limit on stream productivity and trout habitat. Therefore, this flow statistic is indicative of the flow below which trout populations may come under stress. It is important for sustainability of the trout fishery to provide higher flow of at least the 7DMALF, for trout spawning migrations in May.
The frequency of flood flows also appears to adversely effect trout populations in the Waipara. Hayes’s (1995) noted that floods with a four year return period coinciding with fry emergence periods have a “dominant influence” on trout density”. Flooding, low flows and high water temperatures mean that the Waipara does not provide good trout habitat.
It is concluded that it is not realistic to try to set a minimum flow for the upper Waipara to provide for trout habitat during the period January to April. However, a flow of about 110 L/s is needed from May to September to facilitate trout migration to and from spawning areas.
It is considered that any resident trout present in Weka Creek would survive under the existing minimum flow regime, i.e. 28 L/s.
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3.6 Flows needed to provide for amenity/recreation values (Objective WQN1 (h)
Amenity values have in part been dealt with in chapter 3.4 because of the connection between amenity values and the rivers surroundings. Water-associated recreational use of the Waipara, except for off-road vehicle use, is limited by the small number of public access points to the mainstem (SH1, Stringers Bridge, Greenwoods Bridge).
One of the attractions of the Waipara is that it is a small, comparatively safe and “intimate” river compared to the settings on the major braided rivers. It is often used by families with small children for these reasons, including for swimming. These water associated and contact recreation activities require the presence of water, preferably flowing, that looks and smells healthy, and should be substantially free of filamentous periphyton mats. It is likely that the flow required for limiting periphyton growth (100 L/s), will most likely provide minimum adequate conditions for these values in the Upper Waipara. These flows are more likely in the early summer months.
Trout fishing requires higher flows, but the mainstem below White Gorge to the Omihi confluence is of limited value both as trout habitat and for fishing.
The river is not highly valued for either jet boating or kayaking, and willow growth on the bed would be a safety hazard for kayakers at times of high flow. Boating can only occur in freshes and floods so is not a factor in setting a minimum flow.
Future amenity values, particularly recreational activities involving access along the bed, are threatened by the ongoing encroachment of willows into the riverbed. A build-up of grasses and woody weeds provides habitat for animals that prey on indigenous riverbed breeding birds, for example, stoats, ferrets, cats, hedgehogs and rats. Woody weeds and willows also affect the natural character, and if willow growth is excessive, it can narrow the active river channel area and reduce braiding. Invading willows are becoming a significant problem in the Waipara River, because large floods are infrequent and generally of insufficient duration and size to remove this type of vegetation once it has established. Willow control to manage flood fairways is possible under the Soil Conservation and Rivers Control Act 1941, by establishing a special rating district. This was proposed by the former North Canterbury Catchment Board in the 1970’s, but was rejected by Waipara ratepayers at the time. A special rating district is still a potential option but it needs community support. Over the last few years, some private willow control has been undertaken in the Weka Creek catchment.
The uncontrolled use of 4WD vehicles, motorbikes, and all terrain vehicles accessing the riverbed is increasingly seen as an important management issue by landowners and concerned stakeholders. Such vehicles, and associated activities such as shooting, are causing significant adverse effects in the area. Vehicles are being dumped in the bed, especially the lower river mouth area. Management of vehicle access to and on the riverbed needs greater attention than in the past. This is not however, an issue that can be addressed in a flow and allocation regime.
The existence of AMF (ad medum filum aquae) rights means that adjacent landowners have ownership of much of the bed to the centreline of the river. Trespass rights do apply in these situations and landowners can refuse requests for access to riverbeds where AMF rights exist. Many members of the public are not aware of AMF rights and may believe that the entire bed is in Crown ownership, which is not correct in the Waipara. Smaller areas of the riverbed are a mixture of Crown Land and Conservation area and Reserve. No coherent strategy or consistent set of rules for managing access and the use of vehicles on the bed exists. Again this is not something that setting a flow regime can address. Resolution of this issue will require the co-operation of landowners, LINZ, DOC, Hurunui District Council, Environment Canterbury and the Police working together to provide clearer public information and management of access on the riverbed. This will require the setting of appropriate rules or bylaws and information, education, and enforcement to effectively manage this issue.
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3.7 Flows needed to remove excessive periphyton, fine sediment, and invading woody weeds
The Waipara River is high in phosphorous and nitrogen (Hayward 2003). The combination of nutrients, warm weather, prolonged low flows (less than 100 L/s) with accompanying lower water velocities, leads to the development of thick undesirable filamentous periphyton algae mats that dominate over other algal species within the periphyton community. Studies of rivers by NIWA concluded that the river’s degree of enrichment needs to be considered when assessing minimum flows (Suren 2003). Abstractions have the potential to prolong the periods when the flow is under 100 L/s and the effect of this will be to increase the occurrence and duration of undesirable growths of filamentous green algae and thick algal mats.
Floods and freshes play a vital role in maintaining the instream values. For the purposes of this discussion, a fresh is a period of higher flow, usually marked by dirty water that is sufficient to remove periphyton algae and flush out fine sediment. A flood is a larger, less frequent event that is sufficient to rework the gravel bed. Large floods can remove invading woody plants such as lupin, gorse, and broom, and in very large floods, willows can be removed. Floods are considered to be equivalent to the top 1% of the annual flow, or in this case, flows of over 34 cumecs (Chater 2002).
After a flood has turned over and bared clean gravel, periphyton (aquatic communities of different species of algae and bacteria) slowly build up, coating the stones and providing food and shelter for aquatic organisms, which themselves build up in abundance and provide food for fish and birds. As time passes, the composition of the different species that makes up the periphyton community changes. As filamentous green algae density increases the invertebrate population changes from insects such as mayflies, caddisflies, and stoneflies, to snails, and then to ostracods.
If the period between freshes or floods is long enough, and there are sufficient nutrients in the water, some forms of periphyton start to have large increases in biomass (see figure 7). These large periphyton growths, often seen as long green filaments, change the stream habitat and water chemistry, particularly the pH and oxygen content, and reduce the diversity and abundance of aquatic organisms. Conditions can become lethal for fish. In addition to reducing the life-supporting capacity of the river, these undesirable algae reduce other instream values, e.g. its mauri, natural character, and amenity. The next flood cleanses the river of periphyton, refreshes the gravels, and the cycle begins again. However, if during this period all or most of the fish have died, then the area can only be repopulated if fish that can migrate in from reaches where they have survived. Otherwise repopulation will not occur until the next year during the season when native fish migrate into the river from the sea.
Figure 7: Periphyton Accrual Mosley (2003) From Biggs and Stokseth, 1996
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In between the infrequent floods, freshes, especially those in summer, perform a vital role in cleansing the river of much of its excessive periphyton growths. This helps maintain habitat for invertebrates, and hence the food supply for fish and birds. Hayward’s (2003) work in the Waipara indicates that freshes of 10 m3s can, but do not always, cause the removal of periphyton cover. During the study period, Hayward found that freshes of 40 m3s in all cases did remove periphyton cover.
The hydrology of the river is such that freshes of greater than 9 cumecs only occur 1% of the time in December and March, 2% in January and less than 1% in February and April (see appendix 7). Avoiding artificially reducing the frequency and magnitude of summer flushing flows is therefore important. The risk period for periphyton blooms is the late summer and low flows of greater than 50 days. High temperatures create ideal conditions for periphyton blooms.
Hayward (2003) considers that between freshes, a flow of 100 L/s is needed to help avoid creating conditions ideal for periphyton blooms.
Floods are needed to maintain the braided character of the Waipara River and to remove vegetation so that the open gravel habitat is maintained, especially for riverbed breeding birds. Some of these birds, now considered by DOC to be threatened or rare, do not breed in colonies (e.g. wrybill plover, banded dotterel) and instead require substantial territories of vegetation- free gravel for nesting.
A flow regime can be varied through the year if that is beneficial to meeting the needs of instream values. There appears to be a good justification for having a higher flow from May - September. This is when freshes are most frequent, and are needed to meet the migratory and breeding needs of native fish and trout. Currently most of the irrigation consents are not exercised in the winter period, so that reliability of supply is less important. Higher winter flows also mean that even with a higher winter minimum flow, reliabilities for abstractors taking water to storage will be better than in the summer.
Mosely (2003) did not identify any specific information regarding the flow requirements for the protection of indigenous plants. Partridge thought that the indigenous plant habitat was a nicely balanced system in the Weka Creek and suggested that 28 L/s would be a satisfactory minimum flow.
3.8 Summary of flow requirements for instream values
Figure 8 illustrates the overall seasonal requirements for instream values and draws on the information contained in sections 3.1-3.8 above.
Looking at the range of flow requirements necessary to adequately provide for Objective WQN1 instream values, 80-100 L/s is required from October to April and 110 L/s from May to September for the Upper Waipara.
For Weka Creek, given: i. The existence of irrigation scheme infrastructure and economic development based around Weka Creek (recognised in the 2005 RMA S104 2A amendments); and ii. That Weka Creek goes dry in its lower reaches naturally in summer; and iii. That the fish species are able to survive within the part of the system that flows (due to the Dam structure); the current minimum flow of 28 L/s is sustaining instream values.
.
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(NOT COUNCIL POLICY) COUNCIL (NOT 24
DRAFT OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARARIVER ANDTRIBUTARIES REPORT STAFF
Month
Value June July August September October November December January February March April May Eel Juvenile eel return upstream July-Dec Down stream migration Feb/ July Adult trout Spawning Torrentfish Juveniles return from the sea April to November Spawning Jan- April Periphyton Jan - April risk period for blooms Braided Riverbed Birds Breeding/Fledging September- January
Migration Periods Spawning/Breeding Periphyton risk period
Figure 8: Waipara seasonal requirements
4. Reliability of supply for the Upper Waipara
4.1 Importance of reliability of supply
Reliability of supply is a fundamental issue for irrigators as it affects their ability to plan ahead, make investment decisions, and most importantly, their economic viability. Long-term reliability of supply has several key components, including the percentage of time on average when there are no restrictions, percentage of time on average when there are partial restrictions, and when during the irrigation season restrictions are most likely to occur.
Reliability can be affected by several factors including:
• minimum flow: the higher it is set, the greater the duration and frequency of full and partial restrictions that will be placed on abstraction • The size of the allocation blocks. A series of smaller blocks e.g. A, B, and C, will provide lowest reliability for the C block and highest for the A block. C block abstractors would be cut off when there was only enough flow for A and B. • The number of consents allowed within an allocation block. I there is no cap, each consents granted will progressively reduce the water available for existing consent holders, and the reliability of supply for all consents will be progressively reduced.
4.2 Assessment of the impact of restrictions for 1988 – 2005
A Lincoln Environmental consultancy report to ECan (June 2001) discusses the various matters that need to be assessed to fully evaluate irrigation reliability. They are as follows:
Severity: - the amount of restriction. Frequency: - how many times a year that restrictions can be expected, and how many years in which they will occur. Duration: - how long the restrictions last for. Timing: - when in the production season the restrictions occur
They identify duration as a factor having a large impact on agricultural systems. The report breaks this into four categories:
• 1 day or less: no impact from a practical and agronomic point of view. • 2 -15 days (short events): Low impacts on seasonal production, as soil moisture levels can be lifted relatively quickly within existing irrigation system return periods. • 16-30 days (medium events): significant impact on agricultural and horticultural output as the subsequent delays associated with completing the irrigation rotation will mean that soils will have been at or below plant wilting point for long periods of time. • More than 30 days (long events): severe impact resulting in the failure of the production system, and possibly plant death.
4.3 Effect of restrictions:
NRRP Objective WQN6 and Policy WQN19 introduce partial restriction regimes to encourage fair and equitable sharing of water when the available flow is less than required to meet all abstractors needs. Restrictions on abstraction can take several forms. Commonly these will either be a pro-rata reduction or a stepped reduction. Pro-rata reduction is when a consent condition requires that the rate of take progressively reduces in proportion to the available flow above the minimum flow. For example, if only 50% of the necessary flow is available, then all takes have to reduce their rate of take by 50 No consents for the Upper Waipara have conditions requiring pro-rata or stepped restrictions. In the absence of such conditions, consents can continue taking their full amount
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even when there is only a few litres of flow above the minimum. They must cease taking at the minimum flow. Because takes are downstream of the White Gorge recorder, it is likely that the minimum flow for the upper Waipara has been frequently compromised when flows are close to the minimum. The requirement for partial restrictions, will result in the minimum flow being maintained for longer throughout the river. However, it will also mean the frequency and duration of restrictions on abstractors will increase, In turn this will increase the need for abstractors to roster takes within a water user group.
4.4 Reliability of Supply Upper Waipara and the frequency and duration of restrictions
Raising the current minimum flow will reduce the reliability of supply to existing permit holders and increase the adverse economic impacts. Three minimum flow options have been investigated, and the results are discussed below. Estimates have also been made of the potential costs of mitigating reduced reliability by way of storage. This is discussed in Ford’s (2004) report.
Table 6 shows the total number of days of full restriction, when no water would be available, for each of the three minimum flow options at White Gorge. It covers the months of October – May for the period 1988 – 2005). The general conclusions that can be drawn from Table 6 are that firstly, February and March are consistently the most restricted months, irrespective of the minimum flow. Secondly, any minimum flow above the current minimum flow of 50 L/s will further reduce reliability of supply.
For example, then the current consented volume of takes (173 L/s), would only be available for approximately 44% of the time in January, 40% in February, 34% in March and 62% in April (see flow exceedance tables: Appendix 7). With a 50 L/s minimum flow (status quo) it would only be exceeded 48% in January, 46 % in February, 44% in March, and 66% in April.
The implications of these figures are that we can expect restrictions to be in place for the majority of these months every year. This is irrespective of the minimum flow option, and is largely a function of the amount of the current consented takes.
26 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY) (NOT COUNCIL POLICY) (NOT COUNCIL AND TRIBUTARIES REPORT ON WAIPARA RIVER DRAFT STAFF
Table 6: Reliability from the Upper Waipara River White Gorge October to April (period 1988-2005)
Number of days of full restriction for each minimum flow option
Option 1 50 L/s Option 2 80 Option 3 110 green L/s blue L/s red
October November December January February March April May Total 1988 0 0 0 0 0 0 0 15 22 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 22 1989 0 0 0 0 0 0 0 0 0 0 18 25 0 0 2 0 1 21 0 0 0 0 0 0 0 19 48 1990 0 0 0 0 0 0 0 0 2 0 0 7 0 6 13 0 4 15 0 1 18 0 0 0 0 11 55 1991 0 0 0 0 0 0 0 0 0 0 3 8 0 5 8 0 0 0 0 0 0 0 0 0 0 8 16 1992 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 0 8
PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED 1993 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1994 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1995 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 4 1996 0 0 0 0 0 0 0 0 1 0 0 2 0 5 7 0 0 0 0 0 0 0 0 0 0 5 10 1997 0 0 0 0 0 0 0 0 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 1998 0 0 0 0 0 0 0 0 3 9 22 30 28 28 28 11 20 25 0 3 29 0 0 4 48 73 119 1999 0 0 0 0 0 0 0 0 0 22 30 31 25 26 26 0 0 0 0 0 0 0 0 0 47 56 57 2000 0 0 0 0 0 0 0 0 2 0 0 0 0 2 7 0 4 12 0 0 0 0 0 0 0 6 21 2001 0 0 0 0 0 0 0 0 0 0 2 10 0 22 28 4 31 31 0 23 30 0 1 7 4 79 106 2002 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2003 0 0 0 0 0 0 0 0 5 0 0 0 0 0 9 0 14 26 0 0 0 0 0 0 0 14 40 2004 0 0 0 0 0 0 0 0 0 0 2 20 0 0 0 0 0 0 0 0 0 0 0 0 0 2 20 2005 0 0 0 0 0 0 0 0 0 0 0 0 0 2 21 0 2 13 0 0 0 0 0 0 0 4 34 Total 0 0 0 0 0 0 0 15 43 31 77 133 53 96 153 15 76 151 0 27 77 0 1 11 99 292 568
27
Table 7 below, applies the three minimum options to the flow record for 1988 – 2005, and shows the number of events, and in brackets, the years in which they occurred. The duration is in terms of the Lincoln Environmental classification (June 2001) as follows:
• 2 -15 days (short events): Low impacts on seasonal production, as soil moisture levels can be lifted relatively quickly within existing irrigation system return periods. • 16-30 days (medium events): significant impact on agricultural and horticultural output as the subsequent delays associated with completing the irrigation rotation will mean that soils will have been at or below plant wilting point for long periods of time. • More than 30 days (long events): severe impact resulting in the failure of the production system, and possibly plant death.
Table 7: Occurrence of full restrictions in terms of the Lincoln Environmental classification
Minimum Short event Medium event Long event Flow Option 2-15 days 16-30 days more than 30 days Option 1: 1 2000/01 0 2 1997/98; 50 L/s 1998/99 Option 2: 7 1988/89; 1 1988/89 3 1997/98; 80 L/s 1989/90; 1998/99; 1990/91; 2000/01. 1995/96; 1999/00; 2002/03; 2004/05. Option 3: 10 1990/91 4 1989/90 6 1988/89; 110 L/s (four times); (two times); 1997/98 1994/95; 1998/99; (two times); 1995/96, 2003/04. 1998/99; 1998/99 2000/01; (two times); 2004/05. 1999/20 (two times).
Table 8 shows how these occurrences of full restrictions occur in different months and.
Table 8: Full Restriction severity: White Gorge 1998-2005
Minimum Flow Options and Severity Events Month Option 1 (50 L/s) Option 2 (80 L/s) Option 3 (110 L/s) January 1 short 3 short, 5 short, 1 medium 3 medium 3 medium, 1 long
February 2 medium 4 short 8 short, 3 medium 4 medium
March 2 short 4 short, 5 short, 1 medium, 3 medium, 1 long 1 long
Reliability in the Waipara system is usually very good for the early summer up until December. However, January, February, and March are the key months were reliability is low. At the status quo minimum flow of 50 L/s, irrigators have only ever been on full restriction in two of the 17 years of flow record. Both of these events were for significant periods of over 30 days.
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Raising the minimum flow to 80 L/s would have resulted in one extra long event and one more medium event over a 50 L/s minimum flow. It would also result in seven short events which should, according to Lincoln Environmental (2001), be manageable from an irrigation system return period.
Raising the minimum flow to 110 L/s would have had a significant effect on the reliability of supply, by placing irrigators on full restrictions 20 times for the 17 years of hydrological record, or put another way, for 13 years in the last 17 years. This would therefore have considerable effects on farming operations and profitability (see Ford 2004). From a reliability perspective therefore, a 110 L/s minimum flow is a very poor option.
Appendix 9 contains the raw data of the reliability of minimum flows of 50, 80, 110 L/s with an allocation block of 173 L/s for the 1988 to April 2007 period. Reliability is shown in quartiles ie 25%, 50%, 75%. This helps with assessing the duration, timing, significance, and severity of restrictions, all matters considered important by Lincoln Environmental (2001) in assessing reliability. For example, if the restriction periods are clustered in the 0-25% or 25% to 50% bands, then the allocation block is much more available than if it were in the higher quartiles.
In October and November, no full restrictions occur and partial restrictions are rare, and virtually no restrictions occur in the hydrological record for any of the regimes. By December, partial restriction periods of up to 30-40 days occur for all three regimes minimum flow options and are relatively evenly distributed. The first full periods of restriction occur for the 80 L/s option (5 days) and 110 L/s option (22 days), and would be rated as short and moderate events respectively in terms of the Lincoln Environmental (2001) criteria.
In the January to March period the partial restriction periods ramp up in length, to over 100 days over the flow record. The distribution of the partial restrictions changes to one that is skewed towards less partial availability.
By April, the distribution of the restrictions changes with increasing autumn flow, and the distribution of restrictions by options is more even. Full restriction events for April are 3 medium events for the 110 L/s option, and one short event for the 80 L/s option. No period of full restriction occurs with the 50 L/s option.
While creating storage is an option to help mitigate these issues, it is costly. Table 9 outlines the cost to the abstractors from the Upper Waipara River for installing storage facilities to maintain the current reliability of supply at minimum flow options of 80 L/s and 110 L/s. More detail is contained in Appendix 3.
Table 9: Estimates of cost of storage for the Upper Waipara (see Appendix 3 for details)
Actual total rate of take Consented rate of take of 160 L/s 60L/s Option 2 80L/s $0.4 - 0.8 M $0.6 – 1.7 M Option 3 110 L/s $2 – 4 M $5 – 10 M
In summary:
(i) The minimum flow options of 80 L/s and 110 L/s reduce the reliability of supply relative to the current minimum flow of 50L/s, and cause increased economic losses. The 110 L/s minimum flow is much more severe than 80 L/s. (ii) The duration of full restrictions increases with the 80 L/s and 110 L/s minimum flow options, (iii) Storage can help mitigate risks but is expensive. Estimates on the cost of mitigation by the use of storage on minimum flow options have been estimated to range from $0.4 million to $10 million, depending on what assumptions are used.
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5. Evaluation of minimum flow monitoring sites and options for the Upper Waipara
5.1 Introduction
As discussed earlier, an environmental flow regime always incorporates a minimum flow. Having multiple minimum flow regimes and monitoring sites on the same river reach can cause difficulties with irrigator compliance and restriction regimes. It is also desirable to have the same regime for all allocation block abstractors in terms of equitable access to water, from a consent compliance perspective, and for the operation of a water users group.
In determining an appropriate allocation regime it is necessary to look at the flow requirements of both instream values and the requirements of industry and irrigation. While this “weighing” exercise is underpinned by the science and resource information available, by necessity, there is also an element of value judgement applied.
5.2 Minimum flow monitoring site Upper Waipara mainstem
Currently there are two minimum flow monitoring sites on the Upper Waipara River mainstem, White Gorge ( set in 1994) and Stringers Bridge (set 1978). Where practicable, it is better to have a site above the abstractions, preferably recording flows continuously, so that the water available for abstraction can be determined. A site below the abstractions can be used to measure the residual flow and ensure the minimum flow condition is met. Metering of all takes will reduce, but not replace, the need for a down stream monitoring site.
Mosley (2002) in section 7.1.2 (pages 82-83) of his report concluded that a minimum flow site at White Gorge, in conjunction with a site just above the Omihi Stream confluence would…”provide greater certainty that exactly the minimum flow was being maintained, irrespective of how abstractors were exercising their consents”. However, the site at the Omihi confluence is not suitable for a permanent telemetered flow recorder and therefore manual gauging would be needed.
Staff support the conclusion of using the White Gorge as the monitoring site given the presence of a telemetered flow recorder and the predominance of abstractions occurring downstream of it.
For Weka Creek, there is no reason to change the current monitoring site at the Weka Dam.
5.3 Comparative evaluation of minimum flow options (50L/s; 80L/s; 110L/s) against proposed NRRP Objective WQN1
Table 10 below provides a summary of how well the three options satisfy the requirements of Objective WQN1. More detailed information about the flow requirements of the instream values is contained in Appendix 6. See also the discussion on values and flow requirements in Chapter 3. No community water supplies are drawn from the upper Waipara River. Instead, Waipara township gets its supply from the Kowai River and groundwater in the Kowai catchment.
For each minimum flow option there is an addition of flow from Boby Stream which enters the Waipara just below the White Gorge water level recorder. The size of the contribution at 50 L/s at White Gorge will be less than the 19L/s that occurs at White Gorge flows of 80 – 110 L/s.
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Table 10: Comparative Evaluation of Minimum Flow Options: Upper Waipara
Objective Option 1 50 L/s Option 2 80 L/s Option 3 110 L/s WQN1 Attribute (a) domestic stock n/a n/a n/a water drinking water supplies (b) aquatic Not met Largely met Met ecosystem (c) mauri, mahinga Not met Largely met Met kai (d) wahi tapu/taonga Not met Largely met Met (e) natural character Not met Largely met Met (f) natural features Not met Largely met Met landscape (g) significant habitat Not met Not met Met trout (h) amenity Not met Largely met Met
reliability of supply Status quo Reduced reliability Major reduction in reliability
The advantages and disadvantages of each option are discussed below:
5.3.1 Option 1: Status Quo – 50 L/s
Advantages:
1. In relation to full restrictions, current reliability of supply for existing irrigators would remain. Irrigators have only been on full restrictions for two significantly long periods since 1988. 2. Because there is no change in reliability, this regime does not generate the need for additional storage. 3. Best maintains water availability for Waipara’s high value vineyards
Disadvantages:
1. The minimum flow, even with the additional contribution from Boby Creek would not provide an adequate level of protection for the instream values set out in Objective WQN1 and therefore would not promote sustainable management of the Waipara River’s instream values.
5.3.2 Option 2: 80 L/s
Advantages:
1. The Objective WQN1 flow requirements are largely met for most instream values. The exception is trout values that are not met, but the Waipara is not a significant habitat for trout anyway. The 80 L/s plus the contribution of about 19 L/s from Boby Stream raises flow in the reach to approximately 100 L/s which Hayward identified as the minimum needed for water quality purposes, particularly for periphyton management. 2. A minimum flow of 80 L/s would be sufficient to sustain the life supporting capacity for the following indigenous fish in the Upper Waipara system: Canterbury galaxiid, upland bully, and longfin eel. Jowett’s assessment was that 80 L/s would result in
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some habitat loss (5-7%), but the loss would not have any significant effect on the fish population. The additional flow from Boby Creek will assist in improving habitat.
3. As 80 L/s provides for native fish, and with flow from Boby Creek, meets other aquatic ecosystem needs (limiting periphyton growth) it will also provide for species commonly considered to be mahinga kai eg eel. Further, because this option will provide continuity of flow, it better meets the need to provide for mauri.
Disadvantages:
1. The reliability of supply would be less than Option 1, but would be better than at a 110 L/s minimum flow. 2. Existing irrigators collectively would need to invest a moderate level of capital (up to $2 million) in creating additional storage to maintain current reliability of supply.
5.3.3 Option 3: 110 L/s
Advantages:
1. This flow, which is close to the 7DMALF flow of 112 L/s at White Gorge, best meets all the instream values in Objective WQN1 2. Boby Stream would add another 20 L/s to the flows in the river below White Gorge, thereby creating a flow of about 130 L/s. This provides the best aquatic ecosystem conditions of all options.
Disadvantages:
1. A minimum flow of 110 L/s would make the reliability of supply to existing abstractors chronically unreliable compared to other options and cause severe economic impacts. This could have severe impacts on the highly important grape industry unless storage is built.
2. Existing abstractors would need to invest substantial capital (up to $10 million) in creating additional storage to maintain the reliability of supply that exists for Option 1.
5.3.4 Weighing of Upper Waipara mainstem instream and out-of-stream values
(a) Minimum flow October - April
The early summer period is generally reliable under all options. For Option 1 (a minimum flow of 50 L/s), restrictions during January to March tend to occur only during particularly dry years such as 1998 and 1999. Option 2 (minimum flow of 80 L/s) adds one significant long event (2001) compared to Option 1, and six more short periods of restriction. However, according to Lincoln Environmental, the short events should have a low impact on seasonal production. The third option (minimum flow of 110 L/s) would result in a chronic decline in reliability and an extension of the affected period to include December and April.
The current minimum flow of 50 L/s is equivalent to a 1:20 year low flow and it is approximately 45% of the 7DMALF. It is clear from Table 10 that 50 L/s does not provide adequate protection for instream values. In contrast, the 110 L/s option, while it provides the best overall level of protection for Objective WQN1 instream values, it causes a major reduction in reliability of supply. This would cause severe economic problems, both in lost production and in the cost of building storage. These negative effects weigh against this as the preferred option.
32 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Staff consider that a minimum flow of 80 L/s from October – April provides the best balance for meeting the requirements of Objective WQN1. It is consistent with the flow recommended by Jowett to adequately protect indigenous fish. With the addition of about 20 L/s from Bobys Stream it just meets the periphyton flow requirement of 100 L/s. This combined flow will also adequately provide for the other instream values. While reliability of supply is worse than for 50 L/s, the cost of storage to mitigate this is significantly less than for the 110 L/s option.
(b) Minimum flow May - September
Although the Waipara is not a significant trout fishery, it is used by some anglers. To help maintain its current status, it would be advantageous to have abstraction cease at higher flows from May – September, say 110 L/s, to help ensure sufficient water depth for passage to spawning areas. Flows are generally higher through this period and therefore reliability of supply for takes to storage is less likely to be compromised.
Recommendations
1 That a minimum flow of 80 L/s be set at White Gorge (at or about NZMS M34 786- 935) for the period 1 October to 30 April and 110 L/s for the period 1May to 30 September.
5.4 Weighing of Weka Creek instream and out-of-stream values
The rankings given to the values of Weka Creek by NIWA and the Technical Panel assessments and flow requirements for the instream values identified in Objective WQN 1 (a)-(h) are identified in Table 11. The Panellists visited the site on 21 March 2004. They had access to the following information:
• Gauged date: 21 March 2004 • Gauged flow at 28 L/s at Anthills Bridge (just above Weka Creek Dam), 0 L/s at SH7. • 7DMALF estimate: 5 L/s Chater (2002) • Current Minimum flow at Weka Creek Dam: 28 L/s
Table 11: Instream Value ranking and Flow Requirements for Weka Creek Panelist Instream Value Ranking Flow Requirements NIWA Trout Not ranked 8 Partridge Indigenous Vegetation L 28 McManaway Natural character M 28 Amenity L-M Tuahuriri Runanga Mahinga kai M No recommendation Wahi tapu and wahi taonga L-M Mauri L-M
Given that: (i) The irrigation scheme infrastructure and economic development based around Weka Creek already exists (recognised in the 2005 RMA S104 2A amendments); and (ii) Weka Creek goes dry in its lower reaches naturally in summer; and (iii) Fish species are able to survive within the part of the system that flows (due to the Dam structure); (iv) Flows in excess of 1020 L/s spill over the Dam into Weka Creek, and (v) There is only one abstractor, then there appear to be no reasons to alter the existing arrangements for Weka Creek, and the existing minimum flow of 28 L/s adequately sustains the relevant WQN1 values.
Recommendation
That the current minimum flow of 28 L/s for Weka Creek (at or about NZMS M34:864-982) be retained.
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6. Allocation limits – Upper Waipara
6.1 A allocation blocks
Using NRRP Policy WQN14(4), ECan hydrology staff calculated the size of the A allocation block for the Upper Waipara River at White Gorge to be 27 L/s if the minimum flow was set at 50 L/s and zero with minimum flows of 80 or 110 L/s. Given the current size of consented takes, over-allocation is an issue for the Upper Waipara mainstem irrespective of the minimum flow. The policy allows for a local catchment-based solution where this is the most appropriate way to allocate the water resource and resolve possible over-allocation. Such an approach is warranted in this case.
There are a number of factors to be considered in setting the size of the A block. On one hand it can be good for overall economic production, and the community as a whole, to keep expanding the size. However, the downside is that reliability of supply is reduced each time a new consent is issued because all takes will be restricted more often and get less water. Conversely, if the size of the A block is too small, a few consent holders will have a high level of reliability and a large number will have a much poorer level of reliability. This arises because once the A block is fully allocated, water is then only available from additional blocks such as B or C blocks (see figure 2). Takes from these blocks takes are required to cease abstraction at higher flows than the A block takes.
In order to maintain an accurate allocation regime and to maximise the allocation of available water, the Proposed NRRP signals the intention that water be allocated for abstraction for the period of the year the water is required for. For example, a take for direct use for irrigation will be required during the irrigation season, say 1 October to 30 April. Water could then be used to satisfy demand for storage during the off-season, 1 May to 30 September, and it may allow other users access to the resource.
6.2 Cumulative effects of allocation
A total cap on the flow that can be abstracted can be a useful tool for helping to protect the size of freshes that help remove periphyton and fine sediment. The greatest risk to these will come from the cumulative effect of multiple takes into storage from summer freshes. The best way to manage this effect is to set cumulative limits on the total abstraction below 10 cumecs, which approximately is the level which will open the lagoon, and thus is a significant driver of freshwater ecosystem processes in the Waipara catchment.
Mosley (2002, Figure 2, p156) discusses the cumulative effects of an extra one cumec abstraction would decrease the number of eight-cumec freshes by less than one per year, based on a current average of 5.5. He stated that the main effect of an extra cumec abstraction would be to:
“Increase the rate at which flow declines toward base flow levels after each flood peak, thereby reducing slightly the length of time during which flushing flows are maintained.”
Staff consider this to be a useful basis for the cumulative limit of abstraction for the combined B and C allocation blocks. It is recommended that the total amount abstracted under these blocks not exceed 1 cumec in winter at flows below 10 cumecs for the Upper Waipara.
Abstractions, even into storage, are unlikely to have any significant effect on flood flows. In the Waipara, these flood flows are in excess of 34 cumecs and considered high level events. The flows needed to remove periphyton lie between about 10 cumecs and 40 cumecs. Taking a precautionary approach would suggest that a C Block of 1 cumec above 10 cumecs would not adversely effect the functioning of the river ecosystem.
34 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
6.3 Freshes and floods
From an ecological viewpoint, the important flows are those that can open the Waipara river mouth. These flows require approximately eight to ten cumecs. Such flows: • Open the lagoon, and • Remove undesirable periphyton, and • Rework river gravel to remove fine sediment,
Hayward (2003) found that “freshes peaking around 10 cumecs can, but do not always cause sloughing of periphyton cover” and that all periphyton was removed by freshes over 40 cumecs. While some reworking of finer gravel may start at about 10 cumecs, reworking will increase with fresh size. To remove exotic weeds colonising the river bed and maintain natural character, flood flows of at least the mean annual flood – 134 cumecs are needed. Any abstraction, barring dams, is unlikely to affect flows at the annual flood flow level.
Therefore with the present level of abstractions, the setting of upper limits to abstraction (allocation caps) is an issue that should be resolved now so that any storage dams can be designed to ensure that the size of freshes and floods needed to rejuvenate the aquatic habitat and refresh the bed are provided for in the flow management regime. One management approach is to delay any increase in abstraction from the time the river starts to rise until the river flow has peaked.
Each flood in the Waipara River over a two-year period (60 in all) was examined and the average time for a fresh or flood to peak was found to be 10.5 hours. Ceasing any abstraction for 12 hours when the flow exceeds 8 cumecs at White Gorge would ensure a pulse of water unaffected by abstractions could pass down the river and carry out its task of rejuvenating the aquatic habitat. This is complimentary to setting a cap on the total take and is unlikely to have much impact on abstractors. This is because abstractors nearly always take longer to respond to a rise in river flow than the time it takes from the start of a rise in flow until the flood or fresh peaks. However, this may not be the case in the future as the water measurement information becomes increasingly automated and publicly accessible by phone, text, internet services and future media. As water becomes scarce, and block limits are reached, abstractors will tend to become more sophisticated in exploiting every opportunity to harvest water where it is economic and practicable.
6.4 Upper Waipara A allocation block options
6.4.1 A block 1 October–30 April
For the Upper Waipara, the amount of water allocated to existing consent holders is such that the reliability of supply is less than that set out in Policy WQN14. In fact, for February, which is considered the to be consistently the driest month, any combination of minimum flow plus an allocation limit above 173 L/s renders reliabilities below 50% i.e. very poor in terms of reliability. The general overview of reliability is provided in Table 12 below.
However, abstractions of water from streams that are flowing when White Gorge is at its 7DMALF would lead to reductions in flow to the river with consequent losses in reliability of supply to downstream irrigators and loss of flow to sustain instream values. Of all of the contributing streams, Boby Stream makes a significant contribution to upper Waipara flow during low flow periods, and because there are no abstractions from it, it is proposed to have a zero allocation block for Boby Stream.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 35 (NOT COUNCIL POLICY)
Table 12: Reliability of water from the Waipara River at Omihi confluence during the irrigation season Oct to Apr (Based on 1988 to 2003 naturalised synthetic flow record1)
Percentage of time the stated flow is available above the current minimum flow of 50 L/s for Waipara River at Upstream of Omihi Confluence. Oct Nov Dec Jan Feb Mar Apr 60 L/s 100.0 100.0 95.3 79.8 75.7 78.6 87.1 100 L/s 100.0 100.0 86.6 71.4 63.6 68.5 81.6 150 L/s 100.0 99.8 77.4 59.6 54.9 54.6 75.3 250 L/s 100.0 97.2 64.8 46.7 42.8 38.9 62.9 500 L/s 99.8 79.0 50.1 30.5 27.8 19.8 44.9 1000 L/s 81.8 50.3 30.3 18.3 13.3 11.9 25.3
Percentage of time the stated flow is available above a proposed minimum flow of 80 L/s for Waipara River at Upstream of Omihi Confluence. Oct Nov Dec Jan Feb Mar Apr 60 L/s 100.0 100.0 89.0 73.8 66.8 70.2 82.1 100 L/s 100.0 100.0 82.3 63.9 57.9 59.1 78.1 150 L/s 100.0 99.2 73.7 53.5 48.6 49.6 66.2 250 L/s 100.0 96.8 62.1 45.2 40.9 35.5 61.6 500 L/s 99.2 75.8 47.0 29.0 26.6 18.3 43.5 1000 L/s 80.6 48.4 29.5 17.8 13.1 11.5 24.7
Percentage of time the stated flow is available above a proposed minimum flow of 110 L/s for Waipara River at Upstream of Omihi Confluence. Oct Nov Dec Jan Feb Mar Apr 60 L/s 100 100 83.7 65.8 59.8 61.5 79.5 100 L/s 100 99.4 75.8 57.4 52.3 53.6 71.7 150 L/s 100 98.7 70.3 49.2 45.3 42.9 64.1 250 L/s 100 94.3 59.7 41.1 38.6 32.3 60.3 500 L/s 98.2 73.9 45.0 28.4 26.2 17.1 42.6 1000 L/s 79.6 46.9 28.9 17.2 13.1 11.5 23.4
The options for the October – April A block in the Upper Waipara therefore include:
(a) Option 1
An A allocation block comprises all surface water takes and groundwater takes with stream depleting effects exceeding 1 L/s, issued up to 1995, (excluding the 38L/s for Mangatahi Farm Limited). This would result in improved reliability for the pre-1995 abstractors but reduced the reliability for the post-1995 abstractors.
1 A synthetic flow record is a river flow at a specified site on a river, derived from flow relationships rather than an actual measured flow record. The flow relationship is established by measuring the flows at a permanent recorder site and other locations on a river on the same day. This is repeated several times at different flows. The synthetic flow record is derived from the flow record at the permanent recorder site and the flow relationship. Naturalised means that the abstractions have been added back into the record so that the flow at the site is the flow there would have been in the absence of abstractions.
36 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
(b) Option 2
An A allocation block comprises all surface water takes and groundwater takes with stream depleting effects exceeding 1 L/s, issued up to 1 April 2008. Reliability of supply, whatever it is currently would be shared equally by all existing abstractors.
Staff seeks the Community Advisory Group views on the merits or otherwise of these options.
It is technically feasible, and legitimate in terms of NRRP to manage takes so that the stream depletion effect sits just below the 5 L/s threshold set out in NRRP Policy WQN8. On larger waterbodies this may not be an issue. However, for the Waipara, the cumulative effects of say, ten stream depleters at 4.9 litres per second would be significant on instream values and reliability of supply for existing irrigators, especially in the heavily allocated Upper Waipara. It is therefore the view of staff that the stream depletion cut off of 5 L/s is not appropriate for this catchment and it should be set at 1 L/s for the Waipara catchment as a whole.
Takes from groundwater, which have a hydraulic connection to Weka Creek, could reduce the contribution of Weka flows to Waipara River low flows, and also the contribution to the Waipara at high flows above 1020 L/s. These considerations need to be recognised for future management for surface water and hydraulically connected stream-depleting groundwater takes in Weka Creek and the wider Waipara catchment. The best way to manage this, in the opinion of staff, is to:
• cap the existing consent as the A allocation block, and • maintain the existing minimum flow, and • manage stream groundwater takes where the stream depleting effects are greater than 1 L/s, and
Under the NRRP, on plan review, all consents will be called in and technical efficiency issues in water allocation will be addressed under the “reasonable use” test of NRRP Policy WQN17 (2). This means that allocations above what is considered to be above reasonable use will be reduced, hence relieving some allocation pressure. It is also considered that any water freed up under Policy WQN17 should not be reallocated to new or existing consent holders. Similarly, any consents surrendered would not be reallocated. Instead, the improved reliability should accrue to the remaining consent holders, at least until Policy WQN14(4) levels of reliability are obtained. Opportunities to transfer consents, either partially or completely, would still remain however.
Whatever minimum flow regime is adopted, under the NRRP restriction regime of Objective WQN 6 and Policy 19, irrigators will have to accept a greater willingness to share than they would have previously.
6.4.2 Upper Waipara A block 1 May–30 September
To encourage use of winter water, a higher A allocation block could be set, as there is no need to provide the same level of protection from competition for water as in the irrigation season. Harvesting water during the winter period and storing it for summer use is considered a feasible alternative for existing abstractors and for new abstractors to secure a reliable supply. The appropriate size of winter A blocks has not been considered in the NRRP but with the current value of water to irrigators and the lack of suitable summer sources of supply, access to water for winter takes to storage and for frost-fighting is becoming increasingly important.
A conservative winter A block allocation of 300 L/s would supply enough water for approximately twice the current summer usage. This would theoretically allow 25,920 cumecs (300*60*60*24/1000) to be abstracted per day or approximately up to 3,900,000 cumecs over a winter harvest season of 150 days (300*60*60*24*150/1000).
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 37 (NOT COUNCIL POLICY)
Table 13 provides an indication of the reliability of being able to take water from the Waipara River in winter. Each figure is an average of all the days for the month. It lists the probability on any day in each winter month of being able to abstract the flow specified.
Table 13 Reliability of water at Omihi confluence during the winter May to September (based on 2001 winter worst year)
Percentage of time the stated flow is available above the proposed minimum flow of 110 L/s for Waipara River at Upstream of Omihi Confluence. Flow May Jun Jul Aug Sep 250 L/s 0 33 71 100 100 500 L/s 0 10 55 100 100 750 L/s 0 10 52 100 87 1000 L/s 0 7 48 100 53 1500 L/s 0 0 48 90 30 2000 L/s 0 0 48 74 13
Table 13 gives an indication of what happens in the driest winters and it shows that a flow somewhere between 250 and 500 L/s, say 300 L/s, would be available without undue restrictions during most winters. Therefore, staff consider that an A block of 300 L/s be provided for the May to September period.
6.4.3 A block allocation recommendations for the Upper Waipara
1. A zero allocation limit applies to Boby Stream 2 That either:
a An allocation block equal to the sum of the existing surface water takes and stream depleting takes, assessed as per NRRP, issued up to 1995, be established for the period 1 October to 30 April; or
b An A allocation block the sum of the existing summer surface water takes and stream depleting takes, assessed as per NRRP, issued up to 1 April 2008, be established for the period 1 October to 30 April. 3. That NRRP Schedule WQN 1 specifies a stream depletion cut-off limit of 1 L/s for hydraulically connected bores or borefields in the Waipara catchment. 4. That any consents surrendered and water freed up by the reasonable use test not be re- allocated to exiting consent holders or new applicants until NRRP Policy WQN14 (4) reliabilities are met. 5. That an A allocation block of 300 L/s be set for the Upper Waipara during the period 1 May to 30 September. 6. That a delay take rule for the Upper Waipara allocation blocks require abstractors to cease taking for a period of 12 hours when the natural river flow rises above 8 cumecs at White Gorge as estimated by ECan. The purpose of this rule is to protect fresh flows and allow the lagoon to open to the sea.
38 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
6.5 Upper Waipara B allocation block
6.5.1 B blocks and cut-offs
Takes from the B allocation block are cut-off at higher flows than takes from the A block and therefore have a lesser reliability of supply. The cut-off flow is usually calculated by adding the minimum flow to the size of the A block. Their usual purpose is to allow abstractions to storage when the flows in rivers are high, although they could be used for limited irrigation where reliability was not so important. However, if there are no limits placed on the size of the B block all the water above the cut-off flow for the block could be taken and together with the A block abstractions, the river could be kept at the minimum flow for long periods, a state commonly referred to as “flat-lining”. Providing a gap between the blocks prevents flat-lining and helps to ensure flow variability.
There is little in the way of empirical data to assist in quantifying an appropriate size for the gap. The function of the gap is to provide an element of flow variability. In effect, it is a flow sharing mechanism between in-steam values and abstractor needs. It is proposed by staff that the size of the gap between the A and B allocation blocks should be similar to the size of the A block, say 180 L/s. Adding the recommended minimum flow (October-April) of 80 L/s to the A block of 180 L/s plus the gap of 180 L/s would give a cut-off limit for the B block of 440 L/s for the October-April period and 590 L/s for the May-September period (110 L/s plus 300 L/s plus 150 L/s). In the later case the size of the gap remains the same for both periods because of the higher natural variability of flows in the winter.
Failure to have an overall cap, or an allocation limit on abstraction, means that ad hoc decisions are made about cumulative allocations undertaken in consent decisions. Instream stakeholders, such as Fish and Game, Department of Conservation, and Ngai Tahu in particular, support the use of caps as one tool to assist with maintaining flow variability.
Recent case law in water management increasingly supports the use of allocation caps (either instantaneous and/or seasonal volumes) to manage the cumulative effects of abstraction, such as in Lynton Dairy Limited EC 146/04. This view is further reinforced in the Canterbury Strategic Water Study, which recorded in its key findings (S 1.5 p 3) that “a significant constraint on the effective management of Canterbury’s surface water resources is the lack of abstraction limits for the region’s rivers and streams”. The proposed ECan NRRP Policy WQN11 (a) ii) reflects this requirement for the need for seasonal annual volume caps.
The proposed C block comprises a block of one cumec with a cut-off flow of 10 cumecs. The substantial gap between the B and C block is to protect flushing flows that are needed to start removing periphyton.
6.5.2 B Block size
Based on Mosely’s recommendations, ECan staff have considered allocating up to one cumec in winter. However, there are reliability issues that make it prudent to allocate somewhat less than this amount. For the May to September period, setting the size to ensure at least 70% available results in allocation limits of 400 L/s with a cut-off limit of 560 L/s. Reliability of supply is much lower for the remaining periods of the year. Never-the-less, 200 L/s is provided for during October to December, and 150 L/s during January to April, even though the reliability is only about 30 percent. These limits should provide some provision for water harvesting proposals.
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6.5.3 B allocation block cut-off limits and size recommendations for Upper Waipara mainstem
1. That the B allocation block cut-off limit for the Upper Waipara mainstem is set at 440 L/s (1 October to 30 April), and 590 L/s (1 May to 30 September); 2. That the B allocation blocks for the Upper Waipara mainstem be set at 400 L/s for the period 1 May-31 October, 200 L/s for 1 November- 31 December, and 150 L/s for 1 January-30 April.
6.6 C allocation block cut-off limits and block size for Upper Waipara mainstem
Abstractions, even into storage, are unlikely to have any significant effect on flood flows. In the Waipara, these flood flows are 34 cumecs. These are high level events. The flows needed to remove periphyton lie between about 10 cumecs and 40 cumecs. Taking a precautionary approach would suggest that C Block of 1 cumec with a cut-off flow of 10 cumecs would not adversely effect river ecosystem functioning.
Recommendation
That the C allocation block cut-off limit for the Upper Waipara mainstem is set at 10 cumecs with an allocation limit of 1 cumec.
6.7 Weka Creek allocation blocks
Staff are of the view that the A block should be set at the current managed take rate of 1020 L/s because the irrigation scheme already suffers from low reliability and it would be inappropriate to allow new abstractors into the A block.
The current consented take is nearly twice the mean flow. Therefore, the reliability of supply associated with a B allocation block would be very low. As a consequence, it is considered unrealistic to consider a B or subsequent allocation block for this catchment. It would also be prudent to ensure hydraulically connected groundwater takes do not further exacerbate supply reliability.
Recommendations
1. That the A allocation block for the Weka Creek be set 1020 L/s throughout the year. 2. That no B or subsequent allocation block be established for Weka Creek.
40 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
7. Lower Waipara instream values and their flow requirements
Appendix 4 and Appendix 6 lists all the relevant available flow-related information for the instream values of the Lower Waipara River, Omihi Stream and Home Creek, along with the flow requirements for each of the relevant values in Objective WQN1. Also, Chapter 3 contains information that is pertinent to the whole of the Waipara River mainstem.
7.1 Lower Waipara River mainstem
7.1.1 Potable water - Objective WQN1(a)
Currently the Waipara rural water supply is sourced from groundwater in the Kowai catchment, and from Waipara groundwater. Both sources have limited ability to deal with significantly increased demand from urban growth in Amberley. .Discussions with Hurunui asset management staff indicate that it would be prudent planning to reserve an allocation in the Lower Waipara for community purposes, such as drinking water. This can be done by including this within the allocation block system. The lower Waipara catchment below the Omihi stream is the only part of the Waipara surface water system that could provide a reliable run of river source for an expanded Amberley town supply.
7.1.2 Indigenous fish – Objective WQN1(b)
While initial information suggested a minimum flow at Teviotdale of 250 L/s was necessary to adequately provide for indigenous fish in the Lower Waipara, community concerns raised questions about the justification for such a flow. ECan commissioned a further study into the flow requirements of the native fish species that dominate the Lower Waipara, specifically blue gilled bullies, upland bullies, and torrent fish and to identify what an adequate flow would be. Jowett (2006, page 5 & 6) reports as follows:
“…In the Lower Waipara River, a reduction in flow from 425 L/s to 110 L/s causes a substantial (65-78%) loss in habitat for torrent fish and bluegill bullies, but favours upland bullies. The relationship between habitat (WUA) and flow for bluegill bullies and torrent fish is linear, so that habitat loss at a flow of 250 L/s is about half that at a flow of 110 L/s. More than 50% habitat reduction could have an effect on torrent fish and bluegill bullies and at the least would cause some redistribution within the river. Our research in the Waipara indicates that there is a considerable amount of fish movement between habitats, with few fish remaining in similar locations for more than 3 months, and fish moving from runs to riffles as flows decrease. There was also an indication that torrent fish and bluegill bullies would move from low velocity riffles into riffles with higher velocities as flows reduced further. My interpretation of habitat losses in light of these observations is that a habitat loss is not necessarily accompanied by a similar loss in fish numbers, and fish mortality is probably minor until fish densities reach the limit that the habitat will support…”
“…Torrent fish and bluegill bullies are common in South Island east coast gravel Bed Rivers and it is a value judgement whether abstraction should be limited in order to prevent a potential reduction in bluegill bully and torrent fish numbers. I believe that the objective of flow management is to maintain fish populations at a sustainable level. In order to determine an acceptable minimum flow one must know the percentage of time the flow is likely to be at or below that minimum flow. This is often determined by modelling abstractive demands with recorded flows. The decision of what is an acceptable level of sustainability is a matter of opinion and views can vary from the view that any effect is unacceptable to the view that these fish species are widely distributed and any population loss will be re-established by diadromous recruitment. If proposed water use is likely to result in flows being at the minimum for much of the summer, I would suggest a minimum of about 200 L/s or higher if the objective is to have no significant effect on fish…” (Emphasis added)
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 41 (NOT COUNCIL POLICY)
Jowett also observes that torrent fish and bluegill bullies are common in South Island east coast gravel-rivers, and population reductions caused by lower flows will be re-established by recruitment from the sea. This will occur when the Waipara River mouth is open.
7.1.3 Indigenous riverbed birds - Objective WQN1(b)
The Waipara Lagoon /mouth area supports a more diverse range of species than the mainstem, but in late summer the river will naturally go dry immediately above the lagoon and this reduces the areas value for waders and other birds. O’Donnell (2000) ranked the lagoon/mouth area as being of high significance for birds. No specific study has been done for the Waipara to guide minimum flow decisions for riverbed birds. However, flows are naturally higher during the August to December period and therefore, even with abstractions, are likely to provide adequate flows for invertebrate production.
7.1.4 Cultural values – Objective WQN1(c) and (d)
Zygadlo-Kanara and Te Runanga o Ngai Tuahuriri (ECan report U04/01), identified measurable elements of the Waipara’s mauri and how that related to ECan’s river monitoring. That report identified that a minimum flow of 150 L/s was recommended for the Teviotdale site.
7.1.5 Natural character, natural features and landscape, amenity and recreation values – Objective WQN1(f) and (h)
Below Omihi confluence and through the gorge to the sea, natural character and landscape values are higher than for the Upper Waipara. The presence of a higher continuous flow, largely as a result of the significant inflows from the Omihi stream, is an important contributor to the higher value. However, public access to view and use the lower reach is very limited and there are times when continuous flow does not always occur over the last couple of kilometres above the lagoon. Higher flows and the shade through the Lower Waipara reach provides better trout habitat than that existing in the upper catchment.
A minimum flow of 200 L/s would adequately provide for these values.
7.1.6 Trout - Objective WQN1(g)
The Waipara River does not provide significant habitat for trout, and it is generally regarded as a trout fishery of only local importance. The cooler, spring-fed water flowing into the lower reach, particularly during the summer, provides a refuge for trout when the upper reaches become too warm (see figure 7). There is likely to be benefit in providing a minimum flow that is suitable for the protection of fish movement and spawning habitat. A flow of 400 L/s during May to September has been suggested for this purpose. A flow of this magnitude is also likely to assist in ensuring uninterrupted flow to the lagoon.
It is likely that recruitment of sea run trout in spring is also important for maintaining the fishery. Therefore, ensuring abstractions not reduce the frequency/magnitude of freshes that open the mouth, i.e. flows in the 8-10 cumec range.
7.1.7 Flows needed to prolong the River’s connection to the Lagoon/Sea and the effect of loss of flow upstream of the lagoon
Downstream of Teviotdale, the river loses flow to groundwater. Often in summer so much water is lost to the highly permeable gravels that the river goes dry naturally, immediately upstream of the lagoon. The lagoon is rarely open to the sea during January to April as this requires flows of 8-10 cumecs which are infrequent in these months.
42 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
A flow in the region of 400-600 L/s at Teviotdale is needed to maintain flow through to the lagoon. There are few significant benefits from setting a minimum flow in this range because:
• drying generally occurs from January onwards, after the completion of most of the bird breeding that occurs in the lagoon area; • the mouth is closed during low flow periods in the late summer, and most of the migratory native fish species that enter the lagoon in spring when the mouth is often open, will have had time to move upstream beyond the drying reach; • recreational activities relating to water can occur in the accessible areas above the drying reach; • At this flow range, the reach with lowest flow immediately above the lagoon will have such shallow warm water that it will be of little value for the aquatic ecosystem and recreation. This would be particularly so in the hottest summer months January – March.
Maintaining source to sea flow continuity is generally identified as important for both ecological and cultural reasons. However the lower Waipara River goes dry naturally. While abstractions will have some effect inducing premature drying, for the reasons set out above, this is not considered to cause significant adverse effects.
Given that the reach immediately above the lagoon is frequently dry in the latter part of the summer, ECan staff sought additional information on the ecological significance of drying from Jowett (2006). His opinion is that the loss of habitat caused by the riverbed drying immediately upstream of the lagoon is “insignificant”. He is of the view that fish will migrate upstream in search of more favourable habitats at these times. Hayward (pers. comm. 2007) concurs that the loss of flow in this short reach during the January – April period is not likely to have significant adverse effects on the aquatic ecosystem.
Staff are therefore of a view that cutting off the two consented abstractions at a minimum flow of 400-600 L/s at Teviotdale in order to prolong flow through the lower reach of the river to the lagoon in summer is not necessary. There is no significant benefit for instream values and there would be severe impacts on the reliability of supply.
7.2 Objective WQN1 values and flow requirements for Home Creek
On the day of the technical panel site visit, stream champions David McGuckin and Graham Uren provided specific local knowledge about Home Creek to the Technical Panel to assist them in understanding the stream, particularly in relation to the low summer flows, higher winter flows, and very high flows that can occur from time to time as a result of very fast catchment runoff.
The rankings and flow requirements given by NIWA and the technical panellists to the instream values identified in Objective WQN 1 (a)-(h) are identified in Table 14. The panellists visited the creek on 21 March 2004.
They had access to the following information: • Gauged date:21 L/s March 2004 • Gauged flow 44 L/s at Kings Road Bridge, 10 L/s at Casey Farm, 0 at Waipara Springs Winery. • 7DMALF estimates: 21 L/s Kings Road, 0 L/s Omihi confluence. (Chater (2002) • Current minimum flow site - Kings Road Bridge • Current minimum flow - 10 L/s October to April and 57 L/s May to September
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Table 14 Instream value ranking and flow requirements for Home Creek Technical expert Instream Value Ranking Flow Requirements (L/s) NIWA Indigenous fish Not ranked 21 species Partridge Indigenous L None Provided vegetation McManaway Natural character/ L-M 45-50 amenity L-M Tuahuriri Runanga Mahinga kai M 50 Mauri L-M
7.3 Objective WQN1 values and flow requirements for Omihi Stream
The Technical Panel visited five sites on the Omihi Stream:
(a) Baxters Rd Bridge, (b) Waipara Springs Vineyard, (c) “Eatons”, (a site between Baxters Road and Waipara Springs Vineyard), (d) The “Vineyard Bridge”, off the Mt Cass Road, and (e) The Omihi Stream confluence with the Waipara River.
On the day of the Technical Panel site visit, stream champions Michael Eaton, Keith Stackhouse, Steven Ellis, and Chris Parker provided specific local knowledge to the panellists about the Omihi River, its low and flood flows, and the trout, which have been observed in the pools of the river. The stream champions commented that Omihi Stream could on occasions rise quite high.
The rankings and flow requirements determined by NIWA and the technical panel for instream values in Objective WQN 1 (a)-(h) are identified in table 15. The panellists visited the site on 21 March 2004. They had access to the following information:
• Gauged date: 21 March 2004 • Gauged flow 0 L/s at Baxters Road Bridge, 150 L/s Mt Cass Vineyard Bridge, 139 L/s at Waipara confluence • 7DMALF estimates: 0 L/s Baxters Road Bridge, 154 L/s Omihi confluence. • Current Minimum flow: 57 L/s • Current Minimum flow site: Baxters Road.
Table 15 Objective WQN1 instream value ranking and flow requirements for Omihi Stream Panelist Instream Value Ranking Flow Requirements (L/s) NIWA Trout and indigenous 0 Baxters Rd fish 71 Waipara Confluence Partridge Indigenous vegetation L 110-120 Vineyard <139 Waipara confluence McManaway Natural character and L-M 110-120 Vineyard amenity Tuahuriri Runanga Mahinga kai, wahi L-M No recommendation taonga and mauri
44 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
8. Reliability of Supply for the Lower Waipara
The reliability of supply in the Lower Waipara is highly dependent on the contribution of flow from the spring-fed Omihi Stream. While the 7DMALF flow of the Omihi at the confluence is about 220L/s, the flow actually delivered during the irrigation season will be directly affected by the choice of minimum flow on Omihi Stream, and the subsequent amount allocated for abstraction from it in. Therefore it is necessary to manage the Omihi Stream and lower Waipara as one management unit. The following analysis is done under the assumption that the minimum flow and allocation regimes for Home Creek and Omihi Stream will provide the flows used for Teviotdale. The reason for this is that there is no concurrent hydrological data available to do otherwise.
Table 16: Full restriction severity for existing consents Teviotdale May 2000- December 2005
Month Minimum Flow Severity Events 250 L/s 110 L/s January 1 short None February 1 short None 1 medium March 2 short None 1 medium April 1 medium None
Using the Lincoln Environmental (June 2001) criteria to measure the impact of restrictions (see section 4.2, Table 17 outlines what could be expected at a 110 L/s and 250 L/s minimum flow. It lists the days in each month of the irrigation season of being able to abstract the flow specified, and the percentage of each month that represents. The key dry month is February, but the reliability of supply at a minimum flow of 110 L/s is still 100% and restrictions would not be necessary. If it was set at 250 L/s, the reliability of supply would be poorer, and drop to below 60% for the months of February and March for the flow record of 2000-2007.
Given that 110 L/s and 250 L/s represent two extremes, two further minimum flow options have been explored. They are sufficiently different that advantages and disadvantages can be identified in terms of how well they satisfy the requirements of Objective WQN1, including impacts on abstractors. The four options are:
• Option 1: minimum flow of 110 L/s and allowing current and new takes; • Option 2: minimum flow of 250 L/s and allowing current and new takes; • Option 3: minimum flow of 110 L/s and a restricted A block consisting of Croft/Donaldson’s authorised consented instantaneous takes (109 L/s during October and November and 64 L/s during December to September) plus a 20 L/s provision for future community supply needs; and • Option 4: minimum flow of 110 L/s and a restricted the A block of Croft’s measured (2006) take of 19 L/s, Donaldson’s effective take of 30 L/s during October and November and 15 L/s during December to April and a provision of 20 L/s for future community water supply needs.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 45 (NOT COUNCIL POLICY)
(NOT COUNCIL POLICY) COUNCIL (NOT 46
DRAFT OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARARIVER ANDTRIBUTARIES REPORT STAFF
Table 17 Reliability of supply for minimum flow options of 110 L/s and 250 L/s for Lower Waipara (October 2000 to April 2007-actual) Number of days and percentage of time the stated flow is available above the current minimum flow of 110 l/s for the Waipara River at Teviotdale
October November December January February March April
Flow total total total total available number of number of number number of total number total number total number above days out days out of of days days out of of days out of days out of days out 110L/s of 217 % of time 210 % of time out of 217 % of time 217 % of time of 197 % of time of 217 % of time of 210 % of time 60 l/s 217 100 210 100 217 100 217 100 196 100 217 100 210 100 100 l/s 217 100 210 100 217 100 217 100 177 90 187 86 206 98 150 l/s 217 100 210 100 217 100 200 92 153 78 142 65 176 84 250 l/s 217 100 210 100 211 97 149 69 101 51 89 41 158 75 500 l/s 217 100 202 96 159 73 89 41 54 27 50 23 115 55 1000 l/s 185 85 157 75 107 49 50 23 40 20 13 6 56 27
Number of days and percentage of time the stated flow is available above a proposed minimum flow of 250 l/s for the Waipara River at Teviotdale October November December January February March April
total total total total total number of number of number of number of number of total number total number days out days out days out of days out of days out of days out of days out of 217 % of time of 210 % of time 217 % of time 217 % of time of 197 % of time of 217 % of time of 210 % of time 60 l/s 217 100 210 100 217 100 176 81 117 59 97 45 170 81 100 l/s 217 100 210 100 213 98 157 72 104 53 91 42 160 76 150 l/s 217 100 210 100 206 95 133 61 94 48 85 39 148 71 250 l/s 217 100 205 98 180 83 103 48 75 38 63 29 125 60 500 l/s 211 97 191 91 138 64 73 34 47 24 42 19 100 48 1000 l/s 182 84 139 66 95 44 46 21 36 18 4 2 49 23
NB The record used in the analysis covers only 7 years of record. However the record is representative for the flow of the Waipara River, because it covers all flow ranges (including two seasons that were drier than average, according to Waipara at White Gorge data).
9. Evaluation of monitoring sites and minimum flow options for the Lower Waipara
9.1 Minimum flow monitoring sites
9.1.1 Lower Waipara mainstem
It is desirable to have the monitoring site either upstream or downstream of all abstractions. However, a permanent flow recorder site already exists at Teviotdale (at or about NZMS 260 M34:177-124). Even though it is in between the two abstractions, it is in the best location for operational reasons and staff consider that it should be retained as the monitoring site.
9.1.2 Home Creek
Home Creek is a tributary of Omihi Stream. Having one minimum flow site for both Home Creek and Omihi Stream at the confluence of Omihi Stream with the Waipara River was discussed and discounted because Home Creek and Omihi Stream are two quite different systems. Home Creek does not have the groundwater gains that the Omihi Stream experiences, especially during the summer months. A minimum flow site on each was considered to be necessary.
While the monitoring site for current consents is described as Kings Road Bridge, the best gauging site is about 100m downstream of the bridge. There is unlikely to be a significant change in flow between the two sites. Therefore, staff consider that this site should become the minimum flow monitoring site.
9.1.3 Omihi Stream
There are currently two monitoring sites on the Omihi Stream, one at Baxters Road Bridge and the other near the confluence with the Waipara River. Flows at the Baxters Road have ceased since 2000, generally, during the late summer months site, in spite of all abstractions being downstream of this site. Between SH1 and the confluence with the Waipara River, the Omihi stream is a series of attractive pools and the stream gains flow in the river in the lower reaches from spring-fed groundwater.
Staff conclude that managing abstractions from a site below the abstractions would ensure the maintenance of inflows from Omihi Stream into the mainstem of the Waipara River. That site should be near its confluence with the Waipara River.
9.2 Evaluation of minimum flows
9.2.1 Home Creek
NIWA examined many streams in a range of catchments across North Canterbury and classified Home Creek amongst the slow-flowing group of streams. NIWA recorded upland bully and longfined eel at the Kings Road minimum flow site. They described Home Creek as having no high priority species and no significant trout fishery. NIWA’s view was that if the minimum flow was based on the flow required to maintain the habitat preferred by inanga, 21 L/s, even though this species was not recorded and may not be present, this flow would adequately provide for the flow requirements of the native fish species likely to be present.
Partridge commented that the river was heavily shaded by willows in parts and this severely limited indigenous vegetation. Other parts flowed through open grassland and in places the river was or goes dry on occasions. He did not provide a flow recommendation.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 47 (NOT COUNCIL POLICY)
McManaway described the amenity of the river as mainly associated with its landforms, rather than flows, and described the river as picturesque. She recommended a minimum flow of 45-50 L/s.
Tuahuriri Runanga described the river as being prone to seasonal drying up, the eel fishery as probably being healthy, the appearance as good and ranked the tangata whenua values as being low to medium. They recommended a minimum flow of 50 L/s.
The rankings given to instream values were low to medium in all cases. Despite this, higher minimum flows were recommended. Staff note that the flow observed by McManaway and Runanga (44 L/s) was considerably higher than the current minimum flow and the 7DMALF.
There is insufficient flow data to allow a quantitative assessment of raising the minimum flow from 10 L/s for the October – April period. A minimum flow of 45-50 L/s would substantially reduce reliability and result in greater restrictions. Even at 21 L/s there would be an adverse affect although it would be less than that for the 45- 50 L/s minimum flow. The current abstractor has an authorised consent to take 15 L/s but is also restricted to a maximum volume of 7560 cubic metres in any 21 day period. This is an average of less than 5 L/s if taken on a continuous basis.
Given that: (i) Home Creek has no high priority fish species and no significant trout fishery; (ii) the amenity of the river as mainly associated with its landforms, rather than flows; (iii) the eel fishery is probably healthy; (iv) the relatively low amount of water being taken; and (v) the likely impact of greater restrictions arising from an increase in the minimum flow;
staff do not consider that changing the 10 L/s minimum flow for the October to April period is justifiable. However, for the period May to September, instream values, principally indigenous fish and the aquatic ecosystem they are part of, would benefit from having a higher minimum flow to help ensure flow connection. The current May – September minimum flow of 57 L/s is considered adequate to allow re-colonisation and recovery of Home Creek’s aquatic ecosystem, particularly for the passage of larger fish such as eel.
9.2.2 Omihi Stream
NIWA described Omihi Stream as having no high priority native fish species and no significant trout fishery. For slow flowing streams like the Omihi Stream, NIWA (2004, p 23) recommends that “setting minimum flows based on the habitat preferences of inanga will adequately represent the flow requirements of the native fish likely to be found (shortfin eel, common bully)”. They also consider that the mean annual low flow (7DMALF) is a restricting factor for fish populations and where optimum habitat is more than 1.5 times the 7DMALF, the upper limit on the minimum flow was set at the 7DMALF (154 L/s). Even so, NIWA recommended that fish species would be protected in Omihi Stream with a minimum flow of 71 L/s
Partridge noted that the ecosystem values and indigenous vegetation values were only low to medium except in the Vineyard Bridge reach, which he describes as very good. He recommended a minimum flow of 110-120 L/s at Vineyard Bridge and 139 L/s at the Waipara confluence. While he recommended 139 L/s, i.e. the gauged flow, he also noted that this is more than is needed at this site. The two sites are only approximately one kilometre apart.
McManaway described the Baxters Road section and Omihi confluence section as having few instream amenity values but the section near Vineyard Bridge as having quite special natural character and amenity values. She recommended a minimum flow of 110-120 L/s at Vineyard Bridge.
Ngai Tuahuriri Runanga thought that the tangata whenua values were generally low or low to medium. No flow recommendation was provided.
48 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
There is insufficient flow data to allow a quantitative assessment of raising the minimum flow above the current 120 L/s minimum flow (at the confluence) for the October – April period. It would be likely that a minimum flow of 154 L/s would substantially reduce reliability and result in greater restrictions.
Given that: (i) Omihi Stream has no high priority fish species and no significant trout fishery; (ii) the amenity of the river as mainly of little value apart from the Vineyard Bridge reach; (iii) the tangata whenua values are generally low to medium; (iv) the confluence site is only about one kilometre downstream of the Vineyards Bridge site; (v) Partridge’s recommendation that 139 L/s for the lowly ranked indigenous plant values is more than is needed; (vi) the likely impact of greater restrictions arising from an increase in the minimum flow;
staff do not consider that changing the minimum flow of 120 L/s for the October to April period is justifiable. However, for the period May to September, instream values, principally indigenous fish and the aquatic ecosystem they are part of, would benefit from having a higher minimum flow to help ensure flow connection. While there has not been any minimum flow recommendations made by NIWA or the Technical Panel for the May-September period, staff consider that a flow of near to the 7DMALF, say 150 L/s, is desirable.
9.2.3 Comparative evaluation of minimum flow options for the Lower Waipara mainstem
Table 18 below provides a summary of how well four options satisfy the requirements of Objective WQN1. This is followed by a brief discussion of the reliability of supply implications of each option. More detailed information about the flow requirements of the instream values is contained in Appendix 6. See also the discussion on values and flow requirements in Chapter 2.
Table 18: Comparative Evaluation of Minimum Flow Options: Lower Waipara for October - April
WQN1 Attribute Option 1 Option 2 Option 3 Option 4 (a) potable water No change No change No change No Change (b) aquatic ecosystem Not met Met Largely met Met (c) mauri mahinga kai Not met Met Largely met Met (d) wahi tapu /taonga Not met Met Largely met Met (e) natural character Not met Met Largely met Met (f) natural features Not met Met Largely met Met landscape (g) significant habitat Not met Met for trout Largely met Met for trout trout (h) amenity Not met Met Largely met Met
reliability of supply Very high Reduced Very high for Very high for reliability existing, existing (still high reduced but measured relative to still high for take, reduced Upper new consents. but still high Waipara) for balance of existing & new consents
An overview of the advantages and disadvantages of each option is discussed below:
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 49 (NOT COUNCIL POLICY)
(a) Option 1: 110 L/s at Teviotdale Recorder October - April
Advantages:
1. This option would protect the two existing irrigators’ excellent reliability of supply.
2. It would also provide a very high reliability of supply for future abstractors.
Disadvantages:
1. This option would not adequately protect Objective WQN1 instream values, especially aquatic ecosystem values. It is substantially lower than the native fish requirements as specified by Jowett (2006). When Mosley recommended 110 L/s as the minimum flow for the lower Waipara, he was unaware of the flow loss below Teviotdale.
(b) Option 2: 250 L/s at Teviotdale Recorder October – April
Advantage:
1. This flow would adequately protect the instream values outlined in Objective WQN1 for the October – April period.
Disadvantages:
1. Raising the minimum flow for Croft and Donaldson would reduce their reliability of supply from one where they have never been cut off to one where they may face some restriction late in some summers.
2. Raising the minimum flow for Croft and Donaldson would have very little benefit in terms of prolonging flow in the reach immediately upstream form the lagoon.
(c) Option 3: 110 L/s at Teviotdale Recorder (allocation restriction of Croft and Donaldson instantaneous rate of takes and a community water supply), 250 L/s for all new consents, October - April
Advantages:
1. The existing consent-holders reliability of supply would be maintained at a very high level.
2. The flow of 250 L/s is sufficient to sustain Objective WQN1 values. Having this higher minimum for new consents prevents abstraction from reducing flows to the point where the lower Waipara no longer functions as a refugia for fish and other aquatic life when the Upper Waipara has low flows.
3. Because of inflows from the Upper Waipara, Omihi Stream and resurfacing groundwater, river flow in this reach is rarely going to fall to near 110 L/s, so instream values would seldom be subject to such flows.
Disadvantages:
1. New applications to take (not replacements) would have to come from a B block with its higher cut-off level. However, it is likely that any B block abstractors on the Lower Waipara will still have reasonable supply reliability in most years.
50 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
2. There is a very small effect on inducing drying in the reach immediately above the lagoon although the adverse effects of this have been assessed as being minor.
(d) Option 4: 110 L/s (plus an allocation restriction of Croft’s measured take, Donaldson’s effective rate of takes and a community water supply ) This option has the same advantages and disadvantages as Option 3 except that the effect the consents have on inducing drying, albeit minor, cannot be increased because the balance of their consented take will have 250 L/s as its minimum flow.
9.2.4 Weighing of Lower Waipara instream and out-of-stream values for selection of the minimum flow
Meeting Objective WQN 1 requirements necessitates a relative weighing between instream and out-of-stream values to finally assess a suitable environmental minimum flow. This, by necessity, may involve value judgements.
(a) Minimum flow October – April
Four minimum flow options have been considered in 9.2.3 above. A comparative summary is provided in Table 19 below.
Table 19: Comparative summary of options Option Reliability for existing Reliability for new takes Degree of takes environmental protection 1 Very good Very good Very poor 2 Reasonable Reasonable Very good 3 Very good Reasonable Moderate – but if Croft’s increase to their full take, level of protection decreases 4 Very good Reasonable for balance Better than moderate of existing and new takes as drying is no worse than at present
Staff are of the view that a flow of 250 L/s is desirable for the adequate protection of instream values. However, the reliability of supply, relative to the current minimum flow of 110 L/s, would be lower. The Lincoln Environmental classification (2001) shows that short restriction periods (2-15 days) would occur from January – April, and medium periods (16-30 days) from February – April. It is noted that such a level of restriction is still less than that which is experienced by abstractors in the Upper Waipara.
The two existing consents for Croft and Donaldson have a minimum flow of 110 L/s. They have only recently been through hearings (2004) and had their consent conditions set. They claim on the basis of these consent conditions to have incurred considerable expenditure in irrigation development. They are concerned that a higher minimum flow will significantly affect their reliability of supply and jeopardise their investment.
For the Lower Waipara, the opportunity exists to put in place a flow regime that provides adequate protection to instream values for all but the last few kilometres of its length, without causing any significant change in reliability of supply for existing abstractions. Staff are of the view that had Mosley, and the ECan consents staff who relied on Mosley’s report, been aware of the flows are lost below Teviotdale, it is likely that the minimum flow based on Teviotdale could have been set higher. Mosley was unaware of this loss as his report says
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that the 110L/s could be set at either Greenwoods Bridge or Teviotdale, indicating he considered there was no difference between them. Croft’s also maintain that because the river goes dry naturally nearly every year below their intake, there are no benefits in setting a minimum flow higher than 110 L/s at Teviotdale to control abstractions in the Lower Waipara River.
Staff consider that requiring cessation of the current abstractions at a high minimum flow to try to prolong continuous flow from Teviotdale to the lagoon would not provide a significant benefit to the ecology or other Objective WQN1 instream values, and would require a very high minimum flow, disadvantaging existing abstractors for little instream benefit.
Abstacting water from a stream should not lead to the stream becoming dry. NRRP Policy WQN3(2):
“(2) Establish and maintain these flow and level regimes by: (e) not allowing abstraction of water to induce a river to go dry:”
In light of the discussion in Chapter 2.4, staff consider the adverse effects of this drying on Objective WQN1 values will be no more than minor and not inconsistent with the policy. However, should the full consented amount be exercised, a greater length of bed would go dry and the adverse effects would probably be more than minor.
Except for significant freshes, that can push a flow to the lagoon irrespective of how low the groundwater storage is, the drying is primarily influenced by the level of storage in the groundwater system in the river gravels. Thus a small increase in flow during a period when the reach has been dry for some time and groundwater levels have dropped may be “soaked up” and flows will not make it to the lagoon. Whereas if the groundwater storage was near full, and the river had only recently gone dry, then it is quite likely that the same small flow increase would produce some surface flow to the lagoon.
While Option 1 provides a very high reliability of supply for existing irrigators, it does not provide an acceptable minimum flow for providing for Objective WQN1 instream values. The flow is too low to provide an adequate level of protection for native fish and other values in this stretch of the river. If additional consents were granted to abstract, this would have a significant adverse effect on extending the drying reach and compromising Objective WQN1 instream values.
Option 2 at 250 L/s for all consents does provide an acceptable flow for the protection of Objective WQN1 values. Analysis of the severity of restrictions indicates that in the 1997/98 1:130 year drought, irrigators would have been on full restrictions for 42 days in the irrigation season, including all of February. In this situation, the Donaldson’s vines would be at risk of dying due to the prolonged full restrictions. However, this is an extreme, low occurrence event and storage would mitigate this risk. The Croft farming operation would also be adversely affected. However, because they are livestock farming and recently carrot cropping, they have other options, albeit at a cost, to bring in alternative food sources, or to complete the carrot rotation by February.
Option 3 is better than Options 1 and 2 for providing for both the economic and instream value limbs of Objective WQN1, However, Option 4 is preferred. because it allows the relatively small amount of abstraction to remain with a minimum flow of 110 L/s, but limits any increase in drying by placing the balance of the existing consent, along with any new consents, in a separate allocation block with a higher minimum flow of 250 L/s i.e. capping the A allocation block This option is considered, on balance, to achieve NRRP Objective WQN1.
52 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
(b) Minimum flow May – September
Requiring abstractions to cease at a minimum flow of 400 L/s would provide better habitat conditions for spawning trout to migrate out of, and back into this reach, would help maintain flow to the lagoon during part of the bird breeding season. Given the higher flows, particularly in July to September, it would not create reliability of supply problems for any new abstractors.
9.2.5 Overall consideration of monitoring sites and minimum flows
At minimum flow conditions, setting the minimum flow at 120 L/s for the Omihi Stream will ensure that a flow of 250 L/s for the Lower Waipara at Teviotdale can also be achieved. The components that make up the 250 L/s are 80 L/s at White Gorge, 20 L/s from Boby Creek, 120 L/s from Omihi Stream and approximately 30 L/s from groundwater between the Omihi confluence and Teviotdale.
Recommendations
1. That the site for monitoring the minimum flow on the Lower Waipara mainstem remains located at Teviotdale (at or about NZMS 260 N34:177-124).
2. That the site for monitoring the minimum flow on Home Creek is located 100 metres downstream of Kings Road Bridge (at or about NZMS 260 N34:921 979).
3. That the site for monitoring the minimum flow on Omihi Stream is located near the confluence of the Waipara River (at or about NZMS 260 N34:922 923).
4. That the minimum flow for the Lower Waipara at Teviotdale be set at 110 L/s for the period 1 October to 30 April and 400 L/s for the period 1 May to 30 September.
5. That the minimum flow for Home Creek remain at 10 L/s for the period 1 October to 30 April, and 57 L/s for the period 1 May to 30 September.
6. That the minimum flow for Omihi Stream remain at 120 L/s for the period 1 October to 30 April, and is set at 150 L/s for the period 1 May to 30 September.
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10. Allocation Limits – Lower Waipara
10.1 Lower Waipara Block Options
10.1.1 A allocation block (1 October–30 April)
As discussed in chapter 9.2.4, it is recommended that the minimum flow for the Lower Waipara for the October-April period be set at 110 L/s and the allocation limit be capped. In addition, it is considered prudent that an additional 20 L/s be provided for future community water supply needs. This will give an overall block size of 69 L/s for October and November and 54 L/s for December to April inclusive. It is also recommended that any water made available via surrendered consents or freed up under the reasonable use test not be re- allocated to existing or new applicants to better protect instream values.
Recommendations
1. The A allocation block for the 1 October-30 November period be capped at 69 L/s (includes a provision for 20 L/s for future community water supply), and 54 L/s for the period 1December to 30 April (includes a provision for 20 L/s for future community water supply).
2. That any water freed up by consent surrender or by the application of reasonable use tests not be re-allocated to existing consent holders or new applicants.
10.1.2 A allocation block (1 May–30 September)
To encourage use of winter water, a higher A allocation block could be set because there is less competition for water during this period that there is in the irrigation season. The appropriate size of the winter A block has not been considered in the NRRP but with the current value of water to irrigators, access to water for storage and for frost-fighting is becoming increasingly important. The current allocation totals 45 L/s for August and September.
Table 20 provides an indication of the levels of reliability for various levels of takes based on historic synthetic flow record of the driest year for records at the Teviotdale recorder. Each figure is an average of all the days for the month. It lists the probability on any day in each winter month of being able to abstract the flow specified.
Table 20: Reliability of water at at Teviotdale during May to September (based on 2001 – the worst winter year) Percentage of time the stated flow is available above a proposed minimum flow of 250L/s for the Waipara River at Teviotdale May Jun Jul Aug Sep 250 L/s 50 97 100 100 100 500 L/s 0 30 68 100 100 750 L/s 0 10 52 100 97 1000 L/s 0 7 48 100 50 1500 L/s 0 0 48 71 10 2000 L/s 0 0 45 32 0
The table shows that flows up to about 500 L/s occur most of the time. Further analysis reveals that flows of less than 400 L/s during the May-September period would only have occurred for five days in May 2001. Therefore, with the proposed minimum flow of 400 L/s, an allocation of 150 L/s would be available without restrictions during most winters.
Recommendation
1. That an A allocation block of 150 L/s be set for the Lower Waipara for period 1 May to 30 September.
54 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
10.1.3 B and C allocation blocks
The demand for water in the lower reach is less intense than it is in the upper reach. While the reliability of supply is relatively higher, there is still a need to provide for water storage and frost fighting uses. B block allocations are therefore considered appropriate.
However, there is a reach in the Lower Waipara that dries up natural during the late summer period. NRRP Policy WQN3 (2)(e) intends that abstractions should not exacerbate dry reaches, both in time and space. It is therefore recommended that a zero allocation limit for the B block be set for the Lower Waipara for the risk period 1 January to 30 April. Such a regime is also of benefit in maintaining the mauri of the Waipara River. Similarly, there is no C block provision for this period.
Mean winter and spring flows at Teviotdale are well above 1000 L/s. Providing a B allocation block of 250 L/s for the 1 May-31 December period would provide a reasonable level of supply reliability for new abstractors and be sufficient to satisfy any demands into the foreseeable future. For that reason, no C block provision is made. While it has been recommended that the cut-off limit for B block abstraction should be 400 L/s for the 1 October-31 December period, the cut-off for the 1 May-30 September period is higher because of the higher minimum flow recommended for the period. The cut-off is calculated to be 700 L/s (a minimum flow of 400 L/s plus 150 L/s for the A block allocation plus a gap of 150 L/s).
Recommendations
1. That a B allocation block of 250 L/s be established on the Lower Waipara with a cut- off limit of 400 L/s for the period 1 October-31 December, 700 L/s for the period 1 May-30 September; .
2. That no B allocation block allocation be provided for the period 1 January-30 April;
3. That no C allocation block be provided for the lower Waipara.
10.2 Home Creek A and B blocks
There is insufficient flow data to evaluate reliability of supply for an October – April A block in terms of NRRP Policy WQN14. The Strategic Water Study noted that catchments were highly allocated when peak abstraction was over 50% of the 7DMALF. The existing irrigation abstraction of 15 L/s is 75% of the 7DMALF. Staff are therefore of the view that the reliability of supply from October to April for the existing consent holder should be protected by capping the A block at 15 L/s.
Further, because of the low reliability of supply, any reduction in the rate of take arising from application of the reasonable use test at the time of consent review, should not be reallocated. gains be re-allocated. Similarly, for any water freed up by consents being relinquished should not be reallocated until NRRP WQN Policy14 (4) reliabilities are met.
This is a very dry low flow catchment and summer flushing flows are infrequent. Therefore, staff are of the view that it is not desirable to create a B block. This will allow any infrequent freshes during the October – April period to pass through the stream without additional abstraction.
For the April to September period, the existing takes to storage (110 L/s) are large for a small stream, and staff recommend that they also be capped at existing levels and no additional B block be created for this period.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 55 (NOT COUNCIL POLICY)
Recommendations
1. That an A allocation block of 15 L/s be established for Home Creek for the period 1 October – 30 April,
2. That an A allocation block of 110 L/s be established for Home Creek for the period 1 May – 30 April.
3. That no B or subsequent allocation blocks from Home Creek be provided at any time of the year.
4. That any reduction in the October – April A block allocation not be re-allocated to new applicants until NRRP WQN Policy14 (4) reliabilities are met.
10.3 Omihi Stream A and B Blocks
There is insufficient flow data to evaluate reliability of supply for an October – April A block in terms of NRRP Policy WQN14. The Strategic Water Study noted that catchments were highly allocated when peak abstraction was over 50% of the 7DMALF. The existing and pending irrigation abstractions are close to 7DMALF. Staff are therefore of the view that the reliability of supply for the existing consent holder should be protected by capping the A block at 130 L/s.
Further, because of the low reliability of supply, any reduction in the rate of take arising from application of the reasonable use test at the time of consent review, should not be reallocated. Similarly, for any water freed up by consents being relinquished should not be reallocated until NRRP WQN Policy14 (4) reliabilities are met.
This is a very dry low flow catchment and summer flushing flows are infrequent. Therefore, staff are of the view that it is not desirable to create a B block. This will allow any infrequent freshes during the October – April period to pass through the stream without additional abstraction.
To provide future abstraction opportunities, it is recommended that a May to September A incorporates existing consented takes as well as an extra 70 L/s. Given the relatively small size of this stream, staff recommend that no additional B block be created for this period.
Recommendations
1. That an A allocation block of 130 L/s be established for Omihi Stream for the period 1 October – 30 April,
2. That an A allocation block of 200 L/s be established for Omihi Stream for the period 1 May – 30 April.
3. That there is no B or subsequent allocation blocks be provided from Omihi Stream at any time of the year.
4. That any reduction in the October – April A block allocation not be re-allocated to new applicants until NRRP WQN Policy14 (4) reliabilities are met.
56 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
11. Other matters
11.1 Average daily take versus maximum rate of take
Chapter 5 Policy WQN14 indicates a preference for the size of allocation blocks to be determined on the basis of the average daily rates of take because it results in maximising the availability of water. However there are some practical difficulties with this, especially on smaller rivers with a small number of takes, or on small rivers with a large allocation block, or where there are groundwater takes having stream depletion effects (SDE). Therefore in these situations, it is preferable to determine the size of the allocation blocks by using the maximum instantaneous rate of take. While this is slightly inefficient, many irrigation systems can only operate at their maximum rate.
Recommendation
1 That the size of the allocation blocks for the Upper and Lower Waipara River (with the exception of the A block for the Lower Waipara rive mainstem) is calculated on the basis of the maximum instantaneous rates of take.
11.2 Phasing in of any new environmental flow and allocation regimes
The Waipara river users group, comprising irrigators from the Waipara have requested a 15 year time period before changes are made to the regimes. This period is greater than the statutory period for a regional plan, which is 10 years from its operative date. A plan implementation period for environmental flow and allocation regimes of greater than 10 years would therefore be impractical and would defeat the purpose of having a regional plan flow regime.
Waipara catchment minimum flows will not become fully operative until the main body of NRRP Chapter 5 is made operative. This may not be for some time if there are appeals to the Environment Court, which, given the pressure for water, is highly likely. It is anticipated that it will be 2010 at the earliest. After the flow regime is made operative, Council has to call the consents in to have any new flow regime provisions attached. This could take a minimum 12 months.
A regional plan can stipulate the date from which resource consent holders must comply with rules relating to minimum flows and rates of use of water under section 68 (7) RMA. The Variation could specify that the new regime takes effect within, say, two years of the flow regime becoming operative. This would allow Council sufficient time to have completed the call in of consents to have the new flow regime conditions attached.
Given the above, staff are of the view that implementing the reviewed flows once Chapter 5 NRRP is made operative will have given permit holders a lead time of at least five years. Given that:
(i) In 2005, it had been suggested that the minimum flows for the Waipara River should be 110 L/s at White Gorge and 250 L/S at Teviotdale.
(ii) Lower minimum flows are now suggested for both White Gorge and Teviotdale, 80 L/s and 110 L/s respectively.
(iii) The Judge’s coments in Tutton Sienko et.al (W100/95) in the Planning Tribunal.
The lower minimum flows suggested should also be sufficient to avoid the need to have an interim allocation based on actual current takes, whatever they are, as suggested by the Water User Group in 2006.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 57 (NOT COUNCIL POLICY)
Recommendation
That consent reviews will not commence before the Proposed Natural Resources Regional Plan Variation is made operative.
11.3 Flow sharing
A flow sharing regime provides for a proportion of the flow in the river that is above the minimum flow to be left in the river. Flow sharing has been adopted for some rivers in the past on the basis that the sharing helps maintain a more natural regime and this must be better for the ecological functioning of the river.
Flow sharing above a minimum flow generally involves a 1:1 sharing such that if the flow is 100 L/s above the minimum flow, 50 L/s is available for abstraction, and 50 L/s remains in the river. The common rationale for this is that 1:1 sharing helps to avoid abstraction “flat lining” a river at the minimum flow, and also helps to retain natural variations in flow. While intuitively this should be beneficial, there is little or no scientific evidence available to show there are material quantifiable benefits.
NIWA carried out 2-dimensional modelling studies of sections of the Waimakariri, Hurunui, and Rangitata Rivers (NIWA Client Report CHC01/35 and ECan reports U04/19, and U01/41) for a number of species and life-stages and found no evidence to support the view that a sharing regime provides instream ecological benefits. To some extent, a sharing regime can mitigate the effects of a minimum flow regime that is inadequate to protect instream values by keeping the river at a higher flow for longer. Flow sharing is therefore an imperfect substitute for an adequate minimum flow. Duncan’s (2004, page 36) specific recommendation was:
“The minimum flow should be set to ensure that the management objectives can be met because flow sharing may not be able to meet these objectives”. (emphasis added)
Sharing regimes are more restrictive on the volume of water that can be harvested from rivers, than is an adequate minimum flow. Sharing regimes are, in effect, the same thing as a constantly changing minimum flow. Mosley for the Hurunui (2002, p93 notes that: “different sharing regimes have been applied, and there is no particular theoretical justification for this ratio.
Constantly changing minimum flows, river flows, and takes are a difficult mix for managing abstractions from rivers. Sharing rules imply a precision in managing abstractions and residual river flow that is difficult to achieve in practice. They are only possible on rivers where the flow is continuously recorded (Waipara at White Gorge flows are, but flows on the tributary streams are not). There are significant disadvantages to sharing regimes for abstractive users and no demonstrated advantages for instream users. Adequate minimum flows and gaps in the hydrograph, can achieve similar outcomes, with less disadvantages for abstractive users.
11.4 Installation of water meters, data logging, and data transmission
Better management of the water available for abstraction is needed if the Waipara community wants to make more efficient use of the Waipara River water resources to meet their needs.
NRRP Policy WQN16 requires the installation of measurement and recording devices at the point of take or diversion from water bodies. Policy WQN17 (4) provides for a review of the conditions of existing water permits when an allocation regime becomes operative. This will ensure that the water allocation specified on the water permit reflects two things, firstly, the
58 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
actual quantity needed to undertake the land use activity. Secondly, where monitoring indicates that an abstractor has been allocated more than is needed and actually used. This is specified in section 5.6 Regional Rules on page 5-124 of the NRRP.
Collecting this data is required at an international level by the New Zealand Government. It is part of its membership obligations as a member of the Organisation for Economic Cooperation and Development (OECD) to provide information on the use of water. It is also required for national accounting purposes by the Department of Statistics and for general water allocation purposes by the Ministry for the Environment and the Ministry of Agriculture and Forestry.
At a regional level, it is of benefit for ECan to know the real-time demand for water in the catchment. It is important to have accurate information on the actual volumes of water abstracted in relation to allocation limits. This will assist determining the state of the resource and plan effectiveness monitoring.
Flow meters and data loggers are needed to implement this provision. The estimated cost of flow meters and data loggers to each abstractor is several thousand dollars for the larger takes (MfE, 2006). While this is a significant cost, it is a small amount compared to the production benefits the use of the water enables, as well as the consequential increase in land value and production irrigation provides.
MfE are preparing a National Environmental Standard (NES) to ensure the accurate and comprehensive measurement of water takes is undertaken in order to facilitate the sustainable management of New Zealand’s resources. The NES proposes that the data recorded be transferred to Regional Councils at least annually and data be recorded at a minimum of daily intervals. Increasingly technology is emerging that will enable “real time” measurement and this will provide benefits to the Regional Council in terms of consent compliance and water resource allocation planning. It also will provide benefits to abstractors as outlined above.
If all takes affecting surface flows are metered, and the information recorded is relayed immediately to ECan’s Christchurch office, then it will be possible in real time to match the abstractable flow at any time with the combined recorded takes. This would simplify compliance monitoring and could potentially reduce costs for both ECan and irrigators.
Because the Waipara catchment is a water-short area, one of the key steps to improve water management is to install flow meters, data loggers, and real time data transfer to accurately measure the rate and quantity of takes. Once this occurs, more dynamic management by irrigators can occur and the application of the reasonable use test is better informed. It may facilitate the use of water transfers, as provided for under section 136 of the RMA. The smaller scale of the Waipara catchment also lends itself well to an automated management regime as the first in North Canterbury. This will enable audited self-management by irrigators.
Proposed NRRP Policy WQN16 provides for measurement and recording of water abstractions and for a review of water permits where the catchment is defined as being fully allocated. Therefore it is proposed that for each significant take (above 5 L/s) to have a flow meter and data logger with the data to be transferred back in real time to ECan for compliance monitoring purposes. This will involve approximately 18 consent holders in the Waipara. Data transfer will be achieved by the most practicable, cost-effective and reliable option for each relevant take, which may involve options such as radio telemetry, fixed line transmission, or cell phone transmission.
Policy WQN17 (4) provides for a review of the conditions of existing users water permits when an allocation regime becomes operative. This ensures that the water allocation specified on the water permit reflects the actual quantity needed to undertake the land use activity and/or where monitoring indicates that an abstractor has been allocated more than is needed and actually used.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 59 (NOT COUNCIL POLICY)
Permanent telemetered flow recorders have benefits for environmental monitoring, for managing abstractions, for flood warning, and for consent compliance monitoring. The White Gorge flow recorder data is currently telemetered back to Christchurch but data from the Teviotdale water level recorder is not. The cost to upgrade the Teviotdale recorder is estimated at $6000. The total annual cost of managing the two recorder sites is about $20,000 ($10,000 per site).
In the past, the capital cost of setting up these sites has been recovered from the consent holders. Currently, consent holders are charged between $250 and $300 per year per consent towards the cost of maintaining the two permanent recorder sites in the Waipara catchment, with general rates providing the balance. Flows from the Omihi catchment are a key contribution to the Lower Waipara, so in the view of staff, consent holders from that catchment as well as the Lower Waipara consent holders are the primary beneficiaries of the Lower Waipara site at Teviotdale, and should pay a contribution to the collection of site data.
Recommendations
1. Flow meters, data logging, and real-time data transfer of take information is needed to accurately assess significant takes (greater than 5 L/s) from rivers in the Waipara Catchment and this should be done on consent review.
2. The Teviotdale recorder data should be telemetered back to Christchurch at an estimated set-up cost of $6000 funded 50% from the Omihi catchment and Lower Waipara consent user charges and 50% general rates.
60 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
12. Appendices
12.1 Appendix 1 - recommendations of the review
The recommendations of the review are that:
1. That a minimum flow of 80 L/s for the Upper Waipara mainstem be set at White Gorge (at or about NZMS M34 786-935) for the period 1 October to 30 April and 110 L/s for the period 1 May to 30 September.
2 That either:
a An allocation block equal to the sum of the existing surface water takes and stream depleting takes, assessed as per NRRP, issued up to 1995, be established for the period 1 October to 30 April; or
b An A allocation block the sum of the existing summer surface water takes and stream depleting takes, assessed as per NRRP, issued up to 1 April 2008, be established for the period 1 October to 30 April.
shall apply to the Upper Waipara mainstem.
3 That an A allocation block of 300 L/s be set for the Upper Waipara during the period 1 May to 30 September
4. That the B allocation block cut-off limit for the Upper Waipara mainstem is set at 440 L/s (1 October to 30 April), and 590 L/s (1 May to 30 September).
5. That the B allocation blocks for the Upper Waipara mainstem be set at 400 L/s for the period 1 May-31 October, 200 L/s for 1 November- 31 December, and 150 L/s for 1 January-30 April.
6. That the C allocation block cut-off limit for the Upper Waipara mainstem is set at 10 cumecs with an allocation limit of 1 cumec.
7. A zero allocation limit applies to Boby Stream
4. That NRRP Schedule WQN 1 specifies a stream depletion cut-off limit of 1 L/s for hydraulically connected bores or borefields in the Waipara catchment.
8. That any consents surrendered and water freed up by the reasonable use test not be re-allocated to exiting consent holders or new applicants until NRRP Policy WQN14 (4) reliabilities are met.
9. That a delay take rule for the Upper Waipara allocation blocks require abstractors to cease taking for a period of 12 hours when the natural river flow rises above 8 cumecs at White Gorge as estimated by ECan. The purpose of this rule is to protect fresh flows and allow the lagoon to open to the sea.
10. That the current minimum flow of 28 L/s for Weka Creek (at or about NZMS M34:864-982) be retained.
11. That an A allocation block for the Weka Creek be set 1020 L/s throughout the year.
12. That no B or subsequent allocation block be established for Weka Creek.
13. That the site for monitoring the minimum flow on the Lower Waipara mainstem remains located at Teviotdale (at or about NZMS 260 N34:177-124).
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 61 (NOT COUNCIL POLICY)
14. That the minimum flow for the Lower Waipara mainstem at Teviotdale be set at 110 L/s for the period 1 October to 30 April and 400 L/s for the period 1 May to 30 September.
15. The A allocation block for the 1 October-30 November period be set at 69 L/s (includes a provision for 20 L/s for future community water supply), and 54 L/s for the period 1 December to 30 April (includes a provision for 20 L/s for future community water supply) for the Lower Waipara mainstem.
16. That an A allocation block of 150 L/s be established for the Lower Waipara mainstem for period 1 May to 30 September.
17. That a B allocation block of 250 L/s be established for the Lower Waipara mainstem with a cut-off limit of 400 L/s for the period 1 October-31 December and 700 L/s for the period 1 May-30 September .
18. That no B allocation block allocation for the Lower Waipara mainstem be provided for the period 1 January-30 April.
19. That no C allocation block be provided for the Lower Waipara mainstem.
20. That the site for monitoring the minimum flow on Home Creek is located 100 metres downstream of Kings Road Bridge (at or about NZMS 260 N34:921 979).
21. That the minimum flow for Home Creek remain at 10 L/s for the period 1 October to 30 April, and 57 L/s for the period 1 May to 30 September.
22. That an A allocation block of 15 L/s be established for Home Creek for the period 1 October – 30 April,
23. That an A allocation block of 110 L/s be established for Home Creek for the period 1 May – 30 April.
24. That no B or subsequent allocation blocks from Home Creek be provided at any time of the year.
25. That the site for monitoring the minimum flow on Omihi Stream is located near the confluence of the Waipara River (at or about NZMS 260 N34:922 923).
26. That the minimum flow for Omihi Stream remain at 120 L/s for the period 1 October to 30 April, and is set at 150 L/s for the period 1 May to 30 September.
27. That an A allocation block of 130 L/s be established for Omihi Stream for the period 1 October – 30 April and 200 L/s for the period 1 May – 30 April.,
28. That there is no B or subsequent allocation blocks be provided from Omihi Stream at any time of the year.
29. That the size of the allocation blocks for the Upper and Lower Waipara River (with the exception of the A block for the Lower Waipara rive mainstem) is calculated on the basis of the maximum instantaneous rates of take.
30. That any reduction in the October – April A block allocations not be re-allocated to new applicants until NRRP WQN Policy14 (4) reliabilities are met.
31. That any water freed up by consent surrender or by the application of reasonable use tests not be re-allocated to existing consent holders or new applicants.
62 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
32. That consent reviews will not commence before the Proposed Natural Resources Regional Plan Variation is made operative.
33. Flow meters, data logging, and real-time data transfer of take information is needed to accurately assess significant takes (greater than 5 L/s) from rivers in the Waipara Catchment and this should be done on consent review.
34. The Teviotdale recorder data should be telemetered back to Christchurch at an estimated set-up cost of $6000 funded 50% from the Omihi catchment and Lower Waipara consent user charges and 50% general rates.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 63 (NOT COUNCIL POLICY)
12.2 Appendix 2 - list of Waipara River Technical Reports
Technical Reports Aqualinc Research Ltd, 2005. Groundwater Allocation for the Waipara Zone. Technical Report U05/87, Environment Canterbury, Christchurch. (Former Report U05/83 withdrawn) Aqualinc Research Limited (2006). Groundwater Allocation for the Waipara Groundwater Zone – Addendum to Report L05261/1 (19 October 2006). Environment Canterbury, Christchurch. Chater, M., 2002. Waipara River Water Resource. Technical Report U02/84, Environment Canterbury, Christchurch. Chater, M., 2003. 7-day mean annual flow mapping for the Waipara Catchment Area. Technical Report U03/14, Environment Canterbury, Christchurch. Dewson, Z.S, James, A.B.W, and Death, R.G. (2007) Invertebrate responses to short- term water abstraction in small New Zealand streams. Freshwater Biology, 52, 357-369. Duncan, M., 2007. Seven day mean annual low flow mapping of the Waipara Catchment, North Canterbury. Technical Report U08/10 Environment Canterbury, Christchurch. Ford, S., Agribusiness Group, 2005. The Impact of a Change in the Waipara River Flow Management Regime. Technical Report, U05/76, Environment Canterbury, Christchurch. Gabites, S. (2006) ECan memo, 2 May 2006: Intermittent stream recharge from Waipara tributaries. Green, S.R., Greven, M., Clothier, B. (2005) Marlborough Crop Water Use Efficiency Report. Report to Marlborough District Council September 2005 HortResearch Client Report No. 17385 Hayward S. A., Meredith, A.S., Lavender, R.M., 2003. Waipara River: assessment of water quality and aquatic ecosystem monitoring 1999 to 2002. Technical Report U03/11, Environment Canterbury, Christchurch. Horrell, G., 2007. Evidence to NRRP Chapter 5 Policy WQN7, September hearings. Horrell, G.A, Dicker, M.J.I, Pilbrow, R.D, and McFall, K.B. (1998). 1997 / 1998 Drought in the Canterbury Region. ECan Technical Report U98 (31), June 1998. Jowett I., 1994. Minimum flows for native fish in the Waipara River. Technical Report U94/58, Environment Canterbury, Christchurch. Jowett, I. G., Richardson, J., Bonnett, M. L., 2003. Relationship between flow regime and fish abundance in a gravel-bedded river, New Zealand. NIWA research paper. Hamilton, New Zealand Jowett, I. G., 2006. Minimum flows to sustain fish values in the Waipara River. ECan correspondence PL5C/52. Larking, R., 2002. Establishing a relationship between Maori values for water and hydrological monitoring of minimum flows. Technical Report U01/61, Environment Canterbury, Christchurch. Lincoln Environmental (June 2001) Reliability of Supply for Irrigation in Canterbury. Report No 4465/1, Report prepared for Environment Canterbury Lloyd, I., 2002. Groundwater in the Waipara alluvial basin: recharge and allocation. Technical Report U02/27, Environment Canterbury, Christchurch. Lloyd, I., 2002. The Water Resources of the Waipara Catchment and their Management. Technical Report U02/20, Environment Canterbury, Christchurch. Loris, P, 2001. Hydrogeology of the Waipara alluvial basin. Technical Report U00/59, Environment Canterbury, Christchurch. Memon, A.P, Skelton, P. Institutional Arrangements and Planning Practises to Allocate Freshwater Resources in New Zealand: A way forward. NZ Journal of Environmental Law (forthcoming) Ministry for the Environment (1998) Flow guidelines for Instream values. Volume A. Ministry for the Environment, Wellington Morgan, M, Bidwell, V, Bright, J, McIndoe, I, and Robb, C (2002). Canterbury Strategic Water Study. Prepared for Ministry of Agriculture and Forestry, Environment Canterbury, Ministry for the Environment. Lincoln Environmental. Report number 4557/1.
64 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Mosley, M. P., 2003. Waipara River: Instream values and flow regime. Report R03/1, Environment Canterbury, Christchurch. ISBN 1-86937-475-4 NIWA (2004) Minimum flows for selected North Canterbury Streams. ECan report U04/107. August 2004. NIWA (2004) Review of Methods for setting water quantity conditions in the Environment Southland draft Regional Water Plan. NIWA client report HAM2004-018. NIWA Hamilton. Pattle Delamore Partners Ltd, 1996. Preliminary assessment of stream depletion effects from groundwater abstractions in the Waipara River catchment. Report 96/53, Canterbury Regional Council, Christchurch. Suren, et al, NIWA, 2003. Benthic community dynamics during summer low-flows in two rivers of contrasting enrichment. New Zealand Journal of Marine and Freshwater Research, Vol 37:71-83 Wilding, T. K., Jowett, I.G., Meleason, M., NIWA 2004. Minimum Flows for Selected North Canterbury Streams. Technical Report U04/107, Environment Canterbury, Christchurch. Zygadlo-Kanara, F. and Te Runanga o Tuahuriri, 2004 Waipara River Tangata Whenua values. Technical Report R04/01, Environment Canterbury, Christchurch.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 65 (NOT COUNCIL POLICY)
12.3 Appendix 3 - effect on abstractors of proposed changes in flow regime for Waipara River, Home Creek, Omihi Stream, Weka Creek, and Boby Creek
12.3.1 Introduction
Irrigators have requested that the economic impacts on them of proposed changes to the flow management regime on rivers in the Waipara Catchment be assessed. This is not easy to do, because:
• some takes are sporadic; • what abstractors do, and what their consent permits them to do, are often different; • some abstractors have storage facilities to buffer the effect of restrictions on takes during times of low flow and others do not; • some abstractors only take to storages during the winter and others take water whenever they can get it; • there is no continuous hydrological record for Home Creek and Omihi Stream; and • The takes are not measured, so there is no record.
Actual takes are nearly always less than the paper takes (i.e., the amount of water the consent permits authorises that the consent holder is legally entitled to take). To assess the effects properly, there needs to be a continuous flow record (which is only available for the Waipara River) and all takes would have to have had flow meters and data loggers (few or none have).
To try and improve information on the actual take, ECan staff monitored consents over the 2003/04 summer. This provides an assessment of the actual takes, but is a single measurement of each abstractors take at different points in time and may not reflect the normal water take. The above issues highlight the difficulty of making an assessment and having confidence in the result.
Table 21 shows for the Waipara Catchment as at 1/3/05 the:
• consented rate of run-of-river take; • consented rate of run-of-river take averaged over 24 hours during the irrigation season (yellow); • measured rate of take; • measured rate of take averaged over 24 hours (red); and • Abstractors who pump to storage (green).
66 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Consect Status as at 1/3/05 at as Status Consect season rate av. over 24hrs Measured Rate l/ssummer Actual Volumeper daym3 Replacement Application Days Per Irrigation Cycle Irrigation Per Days Measured 03/04 summer Consented Volumem3 Consented Abstraction Start Date Abstraction EndAbstraction Date Actual Hours Hours per day Actual Consented irrigation
Consented Consented Rate l/s rate av. over 24hrs Rate Applied For Applied Rate
Table 21 Consent No as at 1/3/05 at as Nunber 03/04 Table 1 Waipara River Maungatahi Farm Ltd CRC920587 Current CRC022206 50 50 50 Rangatahi Downs Ltd CRC920588 Continuation I4 CRC022207 38 38 38 Maungatahi Farm Ltd CRC012177 Current 22.7 22.7 57 42.8 9561 3693.6 18 7 November April M&SE Porter-not monitored CRC030339.1 Current 15 1.6 1.6 2.63 Tutton Sienko & Hill CRC021176 Current 20.3 20.3 6.7 2.5 1918 217 9 NA November March
Canterbury House Vineyards LCRC940238.1 Current 6.5 6.5 6.5 1.1 2280 93.6 4 7 January March
Fiddlers Green W ines Ltd CRC940475.4 Continuation I4 3 1.5 4.8 3 540 259.2 15 3.5 August March Xenophon Ltd CRC020962 Continuation I4 CRC040325 3 12.5 1.5 4.8 540 259.2 15 3.5 August March Orr CRC041892 9.6 Chapman-not monitored CRC00546.1 Current CRC040244 7.7 7.7 2.6 2.6 222 222 8 Chapman CRC012868 Current 4.7 4.7 Dickson CRC020061 Current 1.2 1.2 Hurunui DC CRC002019 Current 0.9 0.9 P J & M P Smith & Long CRC010463.1 Current 3 3 4.65 2.3 260 234 12 1 July April Total for Waipara River above Omihi confluence 176 154.5 84.5 55.9 15321 4978.6
Below Om ihi confluence W H Croft CRC040492 Current 36 36 43680 14 I M & C C Donaldson CRC040869 Current 28 12 6.9 6.9 1210 1210 14 7 October May IM & C C Donaldson-frost CRC040869 Current 45 1296 1296 8 Amberley Golf Club CRC 011915 Current 1.9 1.9 Total for Waipara River below Omihi confluence 109 48 46186
Om ihi Stream 17.2 17.2 2160 1486 24 3 June May Glenray Farm Ltd CRC920817B.3 Exp Applic A6 CRC032147 25 25 25 5 2.5 216 12 3.5 September April K W Stackhouse CRC011937 Current 26.3 22 26.3 22 32130 1890 20 17 September Decemb East CRC920699B Continuation I4 CRC040848 1.6 5 1.6 24 Allied Domecq W ines Ltd CRC920816A.1 Continuation I4 CRC041657 45 45 45 3888 3888 24 August October Eaton CRC041613 1.4 Total for Omihi Stream 97.9 93.6 48.5 41.7 38178 7480
Home Creek Hutt Creek Vineyard Ltd CRC040279 Current 40 W inter only 38.5 3456 3326.4 24 7 May Septem D C Gould CRC011833 1 Current 15 13 8 15 13 8 7560 1188 22 RP 6/21 November March
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 67 (NOT COUNCIL POLICY)
12.3.2 Assessment of the cost to abstractors of proposed changes to the flow management regime for the Waipara River above Omihi confluence
Environment Canterbury sought advice on the flow regime for the Waipara River. Dr Paul Mosley was commissioned to produce a report, “Waipara River values and flow regime,” R03/1. Mosley considered the flows required to sustain the values listed in the Regional Policy Statement, Chapter 9 Water, Objective 1 (b), (e), (f), (g) and (h) and recommended a flow regime, which in his opinion, would suffice to sustain these values.
Since the October 2005 draft staff report, ECan staff have re-assessed the environmental benefits of minimum flow regimes of 50, 80, and 110 L/s for this reach, based on the science available. The proposal is to change the minimum flow on the Upper Waipara River, but retain the White Gorge site.
The present minimum flows and sites are 50 and 65L/s at White Gorge M34:786 935 and 60 L/s at Stringer’s Bridge M34 830 938. A proposed change would be aimed at better protecting the instream values of the Waipara River, particularly, life supporting capacity, native fish, mauri, natural character, and water quality. The river is relatively high in P and N and during low flows, there are abundant algal growths. Abstractions exacerbate the occurrence and duration of these slimy green growths, which make the river unattractive. The algal growths deplete the oxygen in the water diminishing aquatic life, the food-source of those birds that feed principally on fish and invertebrates in the river.
To analyse the economic effect on abstractors of the proposed changes to the flow management regime, an irrigation model would be employed which matches daily water demand with water availability under the present and proposed regimes for all the years of hydrological record and records the timing and duration of shortfalls in water availability to abstractors. This could allow the present and proposed regimes to be compared to assess the effect on abstractors and the financial performance of their properties. However, there is insufficient information to run such a model. Therefore, the method of analysis described below has been adopted.
The analysis is based on the assumption that:
(a) the cost of providing a storage facility/facilities to accommodate the change in the volume of water that can be harvested from the Waipara River in the worst year under the present and proposed regimes, will reflect the “mitigation cost” to abstractors of restoring reliability of supply;
(b) the change in the flow regime is from a minimum flow of 50 L/s at White Gorge to 80 or 110 L/s at just above Omihi confluence and thereafter throughout the river to the sea;
(c) taking to storage is constant throughout the irrigation season whenever water is available to be taken;
(d) the measured rate of take averaged over 24 hours from table 20 (60L/s) reflects the potential harvest of water to abstractors at their current actual take rate;
(e) the consented rate of take averaged over 24 hours from table 20 (150L/s) reflects the potential harvest of water by abstractors at their consented take rate;
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(f) $52 is the assumed capital cost per cubic metre of water stored in relatively large structures where, if suitable sites can be found, economies of scale can be achieved;
(g) $103 is the assumed capital cost per cubic metre of water stored in smaller on-farm structures.
In relation to (c) above, irrigators do not irrigate at a constant rate for a constant number of hours each day throughout the irrigation season when water is available. Water demand is lower at the start of the season, when the evapotransiration (ET) rates are low, at the end of the season as ET rates fall, when crops are ripening, and when it rains. Therefore this method of analysis would tend to over-estimate the volume needed to offset the change in water availability to abstractors. On the other hand, evaporation and seepage losses can be large, and extra storage is needed to allow for these factors. The assumption in this analysis is that the over-estimate in the volume needed to offset the change in water availability to abstractors equals the losses from leakage and evaporation.
Table 22 gives the days in the worst July to June year, (1997/98) that the natural flow is below specified levels at White Gorge. This was a La Nina drought and assessed as a 1:130 year return period event (Horrell et al. 1998). Table 22 uses the same minimum flows and allocation but assessed for the site just upstream of the Omihi confluence. The flows at Omihi have been determined by correlation with White Gorge. More water is in the Waipara by the time it gets to Omihi and therefore the number of days with restrictions is less than at White Gorge.
Table 22: Number of days that Waipara flow is below a given threshold at White Gorge 1997/98
110L/s minimum flow plus allocation of- 60 L/s 90 L/s 150 L/s Days flow is less than 50 80 110 170 200 260 July 0 0 0 0 0 August 0 0 0 0 0 September 0 0 0 0 0 October 0 000 0 November 0 014 6 December 0 8 29 31 31 January 7 21 30 31 31 31 February 28 28 28 28 28 28 March 11 19 25 31 31 31 April 0 3 30 30 30 30 May 0 4 21 22 25 June 0 0 0 0 0 Total days for irrigation season that flow is less than specified flows 46 71 121 150 155 157
In Table 22, abstractors at the status quo (50 L/s) would be totally restricted for 46 days and have no acess to water for irrigation at all. At a minimum flow of 80 L/s, this total restriction
2 Based on dam storage costs provided by Richard Forbes 3 Based on dam storage costs provided by Tom Porter
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period would be 71 days. For a 110 L/s minimum flow, abstractors would be totally restricted for most of the December to April period.
The implication of this analysis is that the river is heavily allocated and unreliable for irrigation in extreme drought events such as the 1997/98 season. With a 110 L/s minimum flow and a 150 L/s allocation limit, virtually no irrigation at all would be possible in these events, especially in the February-April period.
The extra time in full restriction of a 110 L/s minimum flow compared to an 80 L/s minimum flowis significant. With an 80 L/s minimum flow, the full restriction period is 25 days greater than a 50 L/s minimum flow. Whereas the 110 minimum flow period of full restrictions is significantly greater at 47 days when an 80 L/s is compared to a 110 L/s. This would indicate that, in such drought conditions, the impact of an 80 L/s minimum flow is substantially less than a 110 L/s
Table 23 is the same analysis but at the just above Omihi confluence site where flows are some 20% higher.
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Table 23: Number of days flow is below given threshold in the Waipara just Upstream of Omihi Confluence 1997/98 110L/s minimum flow plus allocation of-
60 L/s 90 L/s 150 L/s Days flow is less than 50 80 110 170 200 260 July 0 0 0 0 0 August 0 0 0 0 0 September 0 0 0 0 0 October 0000 0 November 0001 4 December 0 3 18 29 31 January 5 9 27 31 31 31 February 28 28 28 28 28 28 March 10 11 22 29 31 31 April 0 25 30 30 30 May 0 0 19 21 23 June 0 0 0 0 0 Total days for irrigation season that flow is less than specified flows 43 48 105 136 150 155
Table 23 is based on synthetic record developed from regression analysis of concurrent gaugings below 1000 L/s at White Gorge. It shows that there is a higher reliability of flows at the Omihi, with a 50 L/s minimum flow occurring on 43 days, an 80 L/s occurring on 48, and a 110 L/s occurring on 101 days.
What is significant is that a 80 L/s minimum flow would result in a 5 day increase over a 50 L/s minimum flow, whereas a 110 L/s would double the restriction days.
Table 24: No of days in the 1997/984 irrigation season when there was no water, or only some, water available to abstractors at 110, and 80 L/s. 110 Allocation of 60L/s Allocation 150L/s White Gorge Omihi White Gorge Omihi Min flow 50L/s Confluence Min flow 50L/s Confluence Min flow 110L/s Min flow 110L/s Days no Water 48 105 48 105 Days some 120-48=72 136-105=31 155-48=107 155-105=50 Water 80 Allocation of Allocation of 60 L/s 150 L/s White Gorge Omihi White Gorge Omihi Min flow 50L/s Confluence Min flow 50L/s Confluence Min flow 80L/s Min flow 80L/s Days no Water 48 48 48 48 Days some 72 73 107 127 Water
4 1997/98 had the lowest Waipara River flows over the irrigation season in the hydrological record
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Table 25 shows the calculation of the volume of water that would be lost to abstractors as a result of the change in the flow management regime. It estimates the cost of providing storage to accommodate a similar volume of water for the 1997/98 irrigation season (the lowest flow year). This is based on their measured combined take of 60 L/s averaged over 24 hours, and their consented combined take of 150 L/s averaged over 24 hours.
Table 25: Volume of water lost to abstractors as a result in the change to flow management regime
110 L/s Minimum Flow
Total rate of take 60L/s (measured take) 150L/s (consented take) Change in days no water 105-48=57 105-48=57 Change in days of some water 0.33*1(72-31)=13 0.33(107-50)=19 Days of lost water =70 =76 Lost water volume 70x24x60x60x60=362880m3 76x24x60x60x150=984960m3 Cost/m3 storage low $5*2 $1.8 million $4.9 million Cost/m3 storage high $10*3 $3.6 million $9.8. million Value of land lost 15ha @ $10000=$150000 45ha @ $10000=$450000
80 L/s Minimum Flow
Total rate of take 60L/s (measured take) 150L/s (consented take) Change in days no water 0 0 Change in days of some water 0.33*(72-25)=16 0.33*(107-79)=9 Days of lost water =16 =9 Lost water volume 16x24x60x60x60=82944m3 9x24x60x60x150=116640m3 Cost/m3 storage low $5*2 $414,00 $583,200 Cost/m3 storage high $10*3 $829,440 $1,166,400 Value of land lost 3.5 ha @ $10000=$35,000 5 ha @ $10000=$50,000
*1the assumption is that the reduction in take is not linear, but a recession curve, and that the quantity of water that can be taken as the flow recedes is about a third of the full allocation rather than half. *2based on dam storage costs provided by Richard Forbes *3based on dam storage costs provided by Tom Porter
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12.3.3 Summary of results
Given the assumptions made in this analysis, the proposed change in the flow regime will reduce the opportunity for current consent holders to abstract. The cost of this reduction is estimated to be in the following ranges:
For a 110 L/s Minimum flow
(a) under the measured rate of take (60L/s): • assuming low storage costs, $1.95 million; • assuming high storage costs, $3.75 million (b) under the consented rate of take (150L/s): • assuming low storage costs, $5.35 million; • Assuming high storage costs, $10.25 million.
For an 80 L/s Minimum Flow
(a) under the measured rate of take (60L/s): • assuming low storage costs, $414,000; • assuming high storage costs, $830,000 (b) under the consented rate of take (150L/s): • assuming low storage costs, $583,200; • Assuming high storage costs, $1.2 million.
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12.4 Assessment of the cost to abstractors of proposed changes to the flow management regime for the Waipara River below Omihi confluence
There are two abstractors (Donaldson 12L/s, Croft 36L/s) in the reach of the Waipara River below Omihi confluence. Croft and Donaldson have recently renewed their resource consents. The new consents set a minimum flow condition of 110L/s at Teviotdale. Donaldson’s take is just below the Omihi Stream confluence (upstream of Teviotdale). Croft’s take is below Greenwoods Bridge (downstream of Teviotdale). On the old consents the minimum flow was 80L/s at Greenwoods Bridge. While the intention, when the minimum flows were set on the new consents, was to adopt Mosley’s minimum flow recommendation, it was not realised by the decision maker, that the lower 6 km of the Waipara River below Teviotdale looses flow to groundwater at Greenwoods Bridge and even more of its flow below Greenwoods Bridge.
The reliability of supply enjoyed by Donaldson and Croft through their new consent conditions is enhanced over the old 80L/s condition at Greenwoods Bridge, because when the flow at Teviotdale is 110L/s, the flow at Greenwoods Bridge would have been approximately 60L/s. The proposed raising of the minimum flow at Teviotdale to 250L/s will affect the reliability of supply conferred by the new consent conditions on Donaldson and Croft. However, this is offset to some extent by the proposal to raise the minimum flow of the Upper Waipara River.
Donaldson and Crofts reliability of supply would be only slightly worse under the proposed regime if the new consent conditions had been referenced to Greenwoods Bridge (the same as the old conditions), because the raised minimum flow on the Upper Waipara River would have offset the raised minimum flow at Greenwoods Bridge (110 instead of 80L/s). Under the proposed regime Donaldson and Crofts reliability of supply will fall because their current consent conditions are referenced to Teviotdale and it is proposed to raise the minimum flow at Teviotdale from 110 to 250L/s. Tables 26 and 27 provide an indication of the change in reliability of supply.
Table 26: Average reliability of various levels of abstraction at Teviotdale
Waipara at Teviotdale using derived record 1988 to 2003 Percentage of time stated flow above proposed minimum flow of 250 L/s is available Oct Nov Dec Jan Feb Mar Apr 50 L/s 100 100 100 92.5 86.7 96.2 99.8 60 L/s 100 100 99.4 90.1 86.2 94.8 99.2 100 L/s 100 100 97.6 85.8 79.9 87.5 95.4 150 L/s 100 100 93.9 78.1 74.3 76.2 85.0 250 L/s 100 100 81.5 62.8 56.8 57.5 77.0 500 L/s 100 91.1 55.6 37.2 35.7 27.0 59.1 1000 L/s 77.5 45.9 27.7 16.1 11.4 11.5 23.0 Below minimum flow 0 0 0 2.4 9.8 2.0 0
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Waipara at Teviotdale using derived record 1988 to 2003 Percentage of time stated flow above existing minimum flow of 110 L/s is available Oct Nov Dec Jan Feb Mar Apr 50 L/s 100 100 100 100 100 100 100 60 L/s 100 100 100 100 100 100 100 100 L/s 100 100 100 100 98.6 100 100 150 L/s 100 100 100 96.8 89.7 98.0 100 250 L/s 100 100 96.7 83.4 78.0 84.3 94.1 500 L/s 100 98.1 67.4 48.2 44.2 41.3 63.9 1000 L/s 87.0 57.1 33.2 21.5 15.9 12.5 30.0 Below minimum flow 000 0 000
Table 27: Comparison of worst year reliability of various levels of abstraction at Teviotdale with a minimum flow of 250L/s and a minimum flow of 110L/s
Waipara at Teviotdale using derived record for 1997/1998 Percentage of time stated flow above proposed minimum flow of 250 L/s is available Oct Nov Dec Jan Feb Mar Apr 50 L/s 100 100 100 71.0 0 64.5 100 60 L/s 100 100 100 58.1 0 64.5 100 100 L/s 100 100 100 35.5 0 48.4 96.7 150 L/s 100 100 87.1 6.5 0 22.6 6.7 250 L/s 100 100 29.0 0 0 3.2 0 500 L/s 100 46.7 0 0 0 0 0 1000 L/s 71.0 0 0 0 0 0 0 Below minimum flow 0 0 0 12.9 100 32.3 0
Waipara at Teviotdale using derived record for 1997/1998 Percentage of time stated flow above existing minimum flow of 110 L/s is available Oct Nov Dec Jan Feb Mar Apr 50 L/s 100 100 100 100 100 100 100 60 L/s 100 100 100 100 100 100 100 100 L/s 100 100 100 100 78.6 100 100 150 L/s 100 100 100 83.9 0 67.7 100 250 L/s 100 100 100 29.0 0 35.5 86.7 500 L/s 100 83.3 0 0 0 0 0 1000 L/s 77.4 0 0 0 0 0 0 Below minimum flow 0 0 0 0 0 0 0
For analysis purposes, it is assumed that the combined average 24-hour take rate of the Croft and Donaldson take is 31L/s. The table indicates that for the average situation the change is from 100% reliability in every month of the irrigation season to about 90% reliability in January February and March, which still a very good reliability of supply. However, in the worst year of record the reliability through to the end of January, drops from 100% to 71% in Jan, is zero in February and 64% in March. This gives a total of 48 days when the takes will be on restriction. The calculations are therefore an historic worst case scenario. Table 21 indicates that for 42 of these days the takes will be on full restriction (turned off). To keep the analysis simple it has been assumed that the total restriction is for the full 48 days. The costs of replacing this water by storage can be calculated as follows:
In Donaldson’s case (viticulture), storage would probably be needed and would cost in the range of $250,000 to $500,000 (at an estimate cost of $5 to $10 per m3). In Croft’s case
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 75 (NOT COUNCIL POLICY)
(intensive fat lamb and carrot production), these infrequent years of poor reliability could probably be managed less expensively by a combination of conserved feed,destocking, and completing the carrot production cycle before the dry Febuary period onwards. However, if the fall in reliability of supply was mitigated by installation of water storage structures, the cost would be in the range of $650,000 to $ 1,300,000.
12.3.5 Assessment of the cost to abstractors of proposed changes to the flow management regime for Home Creek and Omihi Stream
At present Home Creek (a tributary of Omihi Stream) monitoring site is at Kings Road Bridge N34:922 982 and Omihi Stream monitoring site is at Baxters Road bridge N34:943 973. The minimum flow at the Kings Rd site is 10 L/s in the irrigation season and 57 L/s in winter and at the Baxters Road site 57 L/s all year. To improve the protection given to the life-supporting capacity of the aquatic ecosystem it is proposed to:
• Change the minimum flow on Home Creek in the irrigation season, Oct. to Apr. from 10 to 20 L/s at a site 100m below Kings Road and in winter, May to Sept at the same site, to 60 L/s, and • Change the monitoring site on the Omihi Stream from Baxters Road to just above Waipara confluence N34:922 922 and to set the minimum for this site at 120 L/s.
• The Home Creek irrigation season minimum flow is being raised from 10 to 20 L/s. The winter minimum flow essentially stays the same (simply rounded off because odd numbers implies an accuracy of measurement that is not practical to achieve). The winter minimum flow will help ensure that, at least in winter, migration of fish can occur throughout the system. The irrigation season minimum flow will help to maintain the oxygen levels in pools and to not permit stress on the aquatic environment more than the system would be exposed to naturally. The rationale for the change in minimum flows and monitoring sites is fully explained in Section 3 of the Staff Report.
There are 3 consents to take water from Home Creek. Two of these are only in winter and one take of about 15 L/s is in the irrigation season, when it is available (Gould). The 15 L/s take will be affected by the decision to raise the irrigation season minimum flow from 10 to 20 L/s. This unreliable water supply will be further reduced in reliability. There are no permanent flow recorders on Home Creek, so the hydrological data is not available to quantify the significance of the adverse effect on the 15 L/s abstraction.
There are a number of springs that enter the Omihi Stream below the existing Baxters Road monitoring site. The new regime will be less restrictive on Omihi irrigators than the present regime (57 L/s at Baxters Road)5. Therefore the proposed new flow management regime will have no adverse effect on present irrigators.
In summary:
• For Home Creek, the change in irrigation season minimum flow will reduce the reliability of supply to Gould’s 15 L/s take, but the hydrological record is not available to quantify the effect. • For Omihi stream, the change in the minimum flow is expected to benefit abstractors, but the hydrological record is not available to quantify to what extent.
5 7day MALF at Baxters Road is zero and at “just above Omihi confluence with the Waipara River” is 220L/s (see table 3 page 12). This implies that the proposed change in the Omihi River flow management regime will be less restrictive on abstractors than the current regime.
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12.3.6 Weka Creek and Boby Creek
It is not proposed to change the current flow regime for Weka Creek; therefore there are no impacts on consented abstractors.
There are no abstractors on Boby Creek, so therefore there will be no changes to any consented abstractors, and any abstraction will reduce the existing reliability of supply for abstractors in the Waipara River.
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12.4 Appendix 4 - Technical Panel field notes for Home Creek, Omihi Stream, and Weka Creek
To take account of the range of values identified in Objective WQN1 of the NRRP, Environment Canterbury arranged for experts in particular areas to undertake assessments and recommend a minimum flow that in their opinion would protect the values of the river within their area of expertise if they felt confident to do so.
NIWA to identify flow levels that would adequately provide for aquatic habitat, report U04/107.
a Technical Panel of experts as follows: Trevor Partridge (freshwater plant ecology); Sue McManaway (landscape and amenity values); and Te Runanga o Ngai Tuahuriri (Tangata Whenua Values).
The field notes of the technical panel made on their site visit to the Waipara tributaries on 24/3/04 are included below. This information was used in the preparation of the Environment Canterbury staff moderation report for Home Creek, Omihi Stream and Weka Creek.
12.4.1 Home Creek
Site visit: 24 March 2004 Current minimum flow site: Kings Road Bridge
Site Flows (L/s) Suggested Minimum Flows (L/s) Current McManaway Tuahuriri Gauged 7DMALF Minimum flow Partridge Runanga 44 @ Kings Rd Bridge 21 57 @ Kings - * 45-50 @ Kings No 10 @Casey Farm Rd Bridge Road Bridge recommendation 0 @ Waipara Springs 1/3 reduction at Winery Glenmark Homestead. * See Partridge’s comments
Stream Character Significance Partridge McManaway Tuahuriri Runanga Natural character L-M Potential L (developed land use) Mauri L-M River mouth (Waipara mainstem) Salmon Trout (reported) Native fish M Mahinga kai M Wahi tapu & wahi taonga L-M Indigenous vegetation L L Boat passage Angling amenity M-L (Mahinga Kai, trout?) L-M L (Stock water, access to Mahinga General amenity kai) L-M (willow Ecosystem Functions Problem) Economics L (Irrigation, commercial eel)
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T Partridge (indigenous habitat) Aquatics: Cress Ludwegia Floating: Lemna, Azolla Margin: Willows – C. Secta (1 seen) creeping bent Banks: Grass and weeds (parsnip)
Values associated with waterway Heavily shaded by willows – severe limitations on vegetation – shingle bottom. The whole system here is ponded. Willows, cress and creeping bent have spread in from the margins and a thick layer of mostly Lemna covers much of the water. This is not a flowing site here. The marginal plants are well in the water. It is therefore difficult to make flow predictions at this site.
Other conditions which would affect the values of the waterway Further up there is flow – Still plenty to maintain values.
Glenmark Homestead Floating:Lemna Aquatics : Myriophyllun, P. crispus, Water Forget-Me-Not Margin: Cress, Water Forget-Me-Not, Creeping Bent. Banks: Grasses, Willows (shade aquatics) Very healthy system with good aquatics ½-1/4 current flow to maintain values.
Casey Farm Under water: Ludweiga (Land leaf form) In Water: Juncus articulatus and dead land plants. Banks: Pasture plants So this site spends a lot of time out of the water – Ludwegia will survive both conditions
Waipara Springs winery Next farm down – Dry at this time – winter flow only Bed: Creeping Bent and weeds on gravel bed. One Pond has Azolla and Aquatic Buttercup
Sue McManaway (natural character) Kings Road Bridge More than one monitoring point may be appropriate along a creek like this with extreme flow variability between reaches.
Some thinning of willow would be just as influential on landscape values as higher flow. Suggest min flow of 45-50 if willows able to be thinned and replaced with indigenous riparian vegetation in some pockets.
Values associated with waterway Land cover: Thick with willows at this point. Cropping/pasture either side. Willow fall. Spring fed. Channel/Flow: serpentine big winds through terraced valley, wide channels, some riffles, pools, gravel bottom. Riparian Edges: Willow. Built Modifications: very few at this point. Water: Clear, pond weed Habitat: Some eels, fish. Amenity: Values mainly associated with landform rather than instream. Patterns/shade reflections in pools. Willows affecting patterns and processes.
Glenmark Homestead Grass, mostly exotic, overgrown hedgerows etc meandering, clear clear water, shingle bottom, some willows but big patches of open space but closed in by landforms and trees. Significant flow today. Quite picturesque in ‘Old England’ way, a little wild. 1/3 reduction. Visible run off- springs.
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Casey’s Farm Grass poplar shelterbelt/cropping. Shingle bottom – ford – dries up (goes under shingle) quite still pool across ford – flow only evident where very shallow, modified channel. Very low natural character, amenity value of having some moving water but marginal more in picturesque setting.
Waipara Springs winery Completely dry, shingle bed – barely recognisable as bed in some spots disappears under shingle.
Tuahuriri Runanga (Tangata whenua values) Kings Road Bridge Water clarity was clear and acceptable. The system is in rolling hill country as a large steep sided complex meandering via a series of deep pools and minor low flowing riffles heavily incised and entrained by erosion. It is sourced from an extensive catchment by rainfall and is supported by a series of small springs along its length. Flows were reported as average for the time of year and were considered down on normal on the day observed. The system is known for extreme high flows. Geology is deep clays overlaid with loess topsoil. Soil moisture retention is not good and is subject to extremes of seasonal wetting and drying. The stream flows through developed pasture and vineyards. Stream substrate is gravels. Riparian areas are devoid of vegetation (pasture only) or are heavily infested with exotic weeds, hemlock and wild carrot and mature willows in some stretches. These provided high levels of shaded and contributed to maintaining the water quality. Odd indigenous shrub specimens occur on bank sides where not accessible to stock. Generally the system is accessible to stock and the bank undercuts are trampled and heavily damaged. Few areas are fenced and pasture is right to the bank side. Instream contained pond weeds and watercress. Invertebrate levels were unable to be assessed but should be moderate health. Bullies were evident and the system supports eels and is known as a fishery. It also supports trout. Notes General appearance is good. Flow should not be allowed to fall so low.
Casey Property Water clarity was clear and acceptable. The system is sited in rolling down land and extensive river flats as flood plains. It is sourced from an extensive catchment (see Home Creek @ Kings Road) and is a continuation of the same system. This section is prone to seasonal drying and goes completely dry Nov-Feb/March. Anecdotal evidence suggests that this system is governed by and prone to extremes. Geology is alluvial deposit with an obvious limestone component. Soil moisture retention is not good and is subject to extremes of seasonal wetting and drying. The stream flows through developed pasture and vineyards. Stream substrate is gravels with the bank sides gentle slopes. Stream structure is small pools and bars connected by minor riffles. Riparian areas are devoid of indigenous wetland vegetation (pasture only) or are covered with sporadic mature willows, poplars and hawthorn in some stretches providing intermittent shading. Few areas are fenced and pasture is right to the bank side in most areas. Generally the system is accessible to stock however this is mainly sheep and the bank undercuts are intact, functioning and undamaged. Instream contained low weed growth with a moderate diversity. The species present indicated low stream nutrient status (i.e. little contamination) and was in moderate health. Invertebrate levels were in moderate density but low diversity and mainly of rapid colonizing species. Bullies were evident and the eel fishery should be moderately healthy. Notes: General appearance is good.
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12.4.2 Omihi Stream
Site visit: 24 March 2004 Current minimum flow site: Baxters Road Bridge
Sites Suggested Minimum Flows (L/s) Gauged L/s 7DMALF Current Partridge McManaway Tuahuriri Minimum Runanga flow L/s Baxters Road Bridge 0 57 No 0 recommendation Vineyard Bridge (434 110 - 120 110 - 120 Omihi Road) 151. Mt Cass Vineyard Bridge 150 Waipara River 187 139 Confluence 139
Stream Character Significance Partridge McManaway Tuahuriri Runanga Natural character L (Willow infested) Mauri L-M River mouth (Waipara mainstem) Salmon Trout L Native fish L Mahinga kai L-M Wahi tapu & wahi taonga L-M Indigenous vegetation L-M L Boat passage Angling amenity L (Mahinga Kai, trout?) General amenity L (Recreation, access to Mahinga kai) Ecosystem Functioning L-M Economics L (irrigation, commercial eel)
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T Partridge (indigenous habitat) Baxters Bridge Aquatics: Water Forget-Me-Not. Floating: Azolla, Lemna Margin: C. secta (7Plants) Bent, Water Forget-Me-Not, Willows. Banks: Pasture, Rushes Dry Areas: Weeds Growing into Bed.
Values associated with the waterway 3 out of 5–4 out of 5 years there is no flow here around June/July each year. Willows may effect flow. Ponds have water
Omihi @ Confluence with Waipara River Aquatics: Gravel System with pools, Algae in open Floating: Lemna, Azolla Margin: Cress, Willows – Willows give much shade - a little monkey musk, creeping bent. Floodplain: Open gravel, willows and weeds of such systems (mullien, bugloss etc).
Impact of willows at this stage are considerable, making a somewhat dysfunctional ecosystem. Considering the stream relationship to areas upstream it is difficult to calculate minimum flow at this site. Otherwise gauged flow is more than what is needed at this site.
Vineyard Bridge @ 434 Omihi Road Aquatics: Algae Floating: Lemna, Azolla Margins: Cress – grows out into ponded area, willow. Banks: Willow and Grasses Floodplain: Grasses, Tall fescue, Creeping bent.
Vineyard Bridge @ Mt Cass Aquatics: Algae, Water Forget-Me-Not, Ranunculus fluitans, Potamogeton crispus. Floating: Lemna, Azolla. Margin: Cress, Water Forget-Me-Not, Creeping Bent, Ludwega Cress, Callitriche. Floodplain: Carex sp. Carex coriacea, Pasture C virgata, J effusus, Eleocharis and Pasture. Banks: Willows, Pasture, Jointed Rush
A very good system down here.
Sue McManaway (natural character) Uncomfortable setting one min flow on a river with such extremes in flow variability along different reaches. Suggest that more than one monitoring site would be appropriate. If monitoring site set up at vineyard bridge, suggest min flow of 110-120 L/s.
Values associated with the waterway Baxters Bridge: Willows thick downstream, some carex on riparian edges otherwise grassed paddocks. Meandering channel through terraced valley water currently in pools – no flow. Stock difficult to fence off because of food events. Murky dark pools of water. Amenity: Few instream amenity values at the time but landform and views raise values – serpentine channel twisting through carved terraces towards coastal ranges.
Omihi @ Confluence with Waipara River: Quite thick willows along shingle banks grassed escarpment above, large expanse of open shingle bed, tyre grooves, clear water, some riffles in flow. Amenity: Shade, access, recreation. Not particularly high scenic/picturesque values.
Vineyard Bridge@ 434 Omihi Road: Some willows but mostly open character, sweeping round to bend with high terraces escarpment above (forestry) some native riparian vegetation (tussocks) otherwise grass to waters edge.
82 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Farm services/structures. Modified channel for ford/bridge at this point. Clear water and natural flow patterns/processes evident. (Stretch of river downstream with natural character and amenity values –quite special).
Tuahuriri Runanga (Tangata whenua values) Omihi @ Confluence with Waipara River Water clarity was clear and acceptable. This is a braided river system and is sourced in rolling hill country from an extensive catchment by rainfall and is supported by a series of small springs along its length. The system is known for extreme high flows. The measuring point is in the Waipara River bed in a semi permanent site. Geology is on alluvial gravels. The stream flows through developed pasture and vineyards. Stream substrate is gravels sands and fine with a high limestone content. Riparian areas are heavily infested with exotic weeds, broom; gorse old mans beard, hemlock, dill and copious mature willows in most stretches in the assessment area. These provided high levels of shaded and contributed to maintaining the water quality. Occasional indigenous shrub specimens occur on bank sides and areas where not accessible to stock. Instream contained watercress and willow weed. Invertebrate levels were low and with moderate levels of snails. Bullies were evident and the system supports eels and trout. Notes: General appearance is good. Vineyard Bridge @ Mt Cass Water clarity was of low quality and surface flow was nonexistent with it unlikely there is any substantial ephemeral contribution. Flows cease November to mid January in 3 out of 5 years. The system is in rolling hill country as a large steep sided complex meandering via a series of deep pools and minor low flowing riffles heavily incised and entrained by erosion. It is sourced from an extensive catchment of large river flats by rainfall and is supported by a series of small springs along its length particularly in the Mt Cass and Wash Creek stretches. The system is known for extreme high flows. This was evidenced by the levels of trash and drift wood on the bank sides. There are a number of large water takes in the upper catchment and the system supports storage dams with high flow abstractions. The stream flows through developed pasture and vineyards. Stream substrate is silts and fine in gravels with a high limestone component. The bed is unstable and slowly constantly moving. Geology is deep clays and rendzenas overlaid with loess topsoil. Soil moisture retention is not great and is subject to extremes of seasonal wetting and drying. Riparian areas are devoid of vegetation (pasture only) or are heavily infested with exotic weeds and mature willows in most stretches. These provided high levels of shade and contributed to maintaining the water quality. Odd patches of indigenous shrub occur where stock access is restricted. Generally the system is accessible to stock and the bank undercuts are trampled and damaged. Generally most of the stock are sheep. Few areas are fenced and pasture generally is right to the bankside. Instream contained pond weeds and high levels of periphyton. Invertebrate levels were unable to be assessed but should be low to moderate in health. The system supports eels and is known as a fishery and also supports trout. Historic accounts of species include flounder and galaxiid species that have largely disappeared from this section. Notes: General appearance is average to poor.
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12.3.4 Weka Creek
Site visit: 24 March 2004 Current minimum flow site: Downstream of Weka Dam
Site Flows (L/s) Suggested Minimum Flows (L/s) Gauged 7DMALF Current Minimum flow Partridge McManaway Tuahuriri Runanga 28 5 28 Downstream of 28 28 No dam recommendation
Stream Character Significance Partridge McManaway Tuahuriri Runanga Natural character M L-M Mauri L-M River mouth (Waipara mainstem) Salmon Trout Native fish M Mahinga kai M Wahi tapu & wahi taonga L-M Indigenous vegetation M (at gauging L-M point) L (Further down) Boat passage Angling amenity M-L (Mahinga Kai) General amenity L-M L (Stock water, access to Mahinga kai) Ecosystem Functioning H (at gauging M (irrigation, commercial eel) point) L (Further down) Economics
T Partridge (indigenous habitat) Weka Dam Floating: Azolla Lemna Margin: Cress, Water Forget-Me-Not, Carex secta Flood Plain: Damp wetland with Carex buchanani, C virgata, Juncus gregiflorus, Isdepis nodosus, Creeping Bent, other grasses, chewed, Cabbage Tree – occasional Willow. Banks: Grasses including Agropyron, scabrum and scattered silver tussock, M complexon. Terrace: Grassland with Agropyron scabrum.
A nicely balanced system up here.
Sue McManaway (natural character) Flow at this point is sufficient to sustain values but it may be appropriate to consider another monitoring point down on the low lands where the rivers values appear to deteriorate and the flow goes underground at some points.
Values associated with the waterway Weka @ Vineyard Lowland: Wide shingle riverbed at this point with steep badly eroding cliff north bank, wide shingle fan south bank. Barely flowing today. Open, terraced landscape low natural elements, patterns, processes. Low amenity value.
Upstream: Higher natural character, closer to foothills.
84 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Weka Dam Below dam, winds through terraced, narrow valley, strong landforms, and mountains in distance. Land cover: Mixture of exotics and natives along riparian edges, grassed paddocks above. Built Modifications: Dam structures and State Highway to Hanmer above. Channel/Flow: Artificial regime regulated by dam. Path and channels appear natural around this point. Some riffles and pools. Riparian Edges: Some willow fall. Water: Clear Amenity: Modified environment but fits well enough into existing landforms not to lower amenity values by much. Can look down at monitoring site from road. Landforms and views main contribution to river amenity values.
Tuahuriri Runanga (Tangata whenua values) Weka Dam Water clarity was very clear. The system arises in rolling to steep hill country as a heavily incised hill stream entrained via a series of deep pools and minor low flowing riffles. It is sourced from a small catchment fed by rainfall and is supported by a series of small springs hill springs and wetlands. The system is known for extreme high flows. Geology is limestone rendzina overlaid with loess topsoil. Soil moisture retention is not good and is subject to greater fluctuations due to the limestone substrate. The stream flows through lightly modified hill pasture. Stream substrate is gravels with a high limestone component. Riparian areas are pasture with matagouri on the slopes and indigenous remnants in the upper catchment. There is a high diversity of wetland sedge and rushes in low areas with numerous carex evident. Weeds are willows hawthorn and briar. Few areas are fenced and pasture is right to the bank side however, most of the stock are sheep and stocking density is not intensive. Instream contained watercress and high levels of sedges and rushes and performed as a small meandering wetland on the stream benches. Invertebrate levels were very high and despite the waterfowl snails were not at excessive levels. Bullies were evident and the system supports eels and is known as a small fishery. The high levels of birds particularly on the dam would not contribute well to water quality. First flush flows in flood events would be heavily contaminated. Notes: General appearance is good.
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12.5 Appendix 5 - Statutory Acknowledgement for Waipara River
Statutory Area
The statutory area to which this statutory acknowledgement applies is the River known as Waipara, the location of which is shown on Allocation Plan MD 113 (SO 19849).
Preamble
Under section 206, the Crown acknowledges Te Runanga o Ngai Tahu's statement of Ngai Tahu's cultural, spiritual, historic, and traditional association to the Waipara River, as set out below.
Ngai Tahu Association with the Waipara River
Tradition tells of the duel between two famous rangatira (chiefs) which happened in this area. Tutewaimate, an Ngati Mamoe rangatira from Rakaia, found that the northward trade route that he sent his goods along was being disrupted by Moko, a rangatira of the Ngati Kuri hapu of Ngai Tahu who had been acting as a bandit along the route. Tutewaimate went to confront Moko, who lived in a cave at Waipara, but found him sleeping. Tutewaimate allowed Moko to awake before attacking him. Tutewaimate's sense of fair play cost him his life and is recalled in a tribal proverb.
For Ngai Tahu, histories such as this reinforce tribal identity and solidarity, and continuity between generations, and document the events which shaped Ngai Tahu as an iwi.
There are a number of Ngati Wairaki, Ngati Mamoe and Ngai Tahu urupa and wahi tapu along the river and associated coastline. Urupa are the resting places of Ngai Tahu tupuna and, as such, are the focus for whanau traditions. Urupa and wahi tapu are places holding the memories, traditions, victories and defeats of Ngai Tahu tupuna, and are frequently protected by secret locations.
The river and associated coastline was also a significant mahinga kai, with kai Moana, particularly paua, being taken at the mouth. The tupuna had considerable knowledge of whakapapa, traditional trails and tauranga waka, places for gathering kai and other taonga, ways in which to use the resources of the river, the relationship of people with the river and their dependence on it, and tikanga for the proper and sustainable utilisation of resources. All of these values remain important to Ngai Tahu today.
The mauri of the Waipara River represents the essence that binds the physical and spiritual elements of all things together, generating and upholding all life. All elements of the natural environment possess a life force, and all forms of life are related. Mauri is a critical element of the spiritual relationship of Ngai Tahu Whanui with the river.
Purposes of Statutory Acknowledgement Pursuant to section 215, and without limiting the rest of this schedule, the only purposes of this statutory acknowledgement are — a)To require that consent authorities forward summaries of resource consent applications to Te Runanga o Ngai Tahu as required by regulations made pursuant to section 207(clause 12.2.3 of the deed of settlement); and
(b)To require that consent authorities, the Historic Places Trust, or the Environment Court, as the case may be, have regard to this statutory acknowledgement in relation to the Waipara River, as provided in sections 208 to 210 (clause 12.2.4 of the deed of settlement); and
(c)To empower the Minister responsible for management of the Waipara River or the Commissioner of Crown Lands, as the case may be, to enter into a Deed of
86 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
Recognition as provided in section 212 (clause 12.2.6 of the deed of settlement); and
(d)To enable Te Runanga o Ngai Tahu and any member of Ngai Tahu Whanui to cite this statutory acknowledgement as evidence of the association of Ngai Tahu to the Waipara River as provided in section 211 (clause 12.2.5 of the deed of settlement).
Limitations on Effect of Statutory Acknowledgement
Except as expressly provided in sections 208 to 211, 213, and 215,—
(a)This statutory acknowledgement does not affect, and is not to be taken into account in, the exercise of any power, duty, or function by any person or entity under any statute, regulation, or bylaw; and
(b)Without limiting paragraph (a), no person or entity, in considering any matter or making any decision or recommendation under statute, regulation, or bylaw, may give any greater or lesser weight to Ngai Tahu's association to the Waipara River (as described in this statutory acknowledgement) than that person or entity would give under the relevant statute, regulation, or bylaw, if this statutory acknowledgement did not exist in respect of the Waipara River.
Except as expressly provided in this Act, this statutory acknowledgement does not affect the lawful rights or interests of any person who is not a party to the deed of settlement.
Except as expressly provided in this Act, this statutory acknowledgement does not, of itself, have the effect of granting, creating, or providing evidence of any estate or interest in, or any rights of any kind whatsoever relating to, the Waipara River.
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OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF 12.6 Appendix 6 – attributes, technical information, and evaluation of main stem flow regime options
Objective WQN1 Attributes / Value to be sustained Source of Minimum Evaluation of Evaluation of informatio flow/flow Upper River Lower River n Regime options Options Provision Recommendati on 50 L/s Option 1 110 L/s Option 1 80 L/s Option 2 250 L/s Option 2 110 L/s Option 3 110 /s +Gap Option 3 (a) drinking water Not a flow regime issue and no surface water take is n/a n/a n/a n/a used for a community water supply in the catchment. ( One well at Amberley CRC 002019 by Hurunui DC) (b) aquatic - 8 native fish species present, 7 species reasonably Jowett Recommended NATIVE FISH NATIVE FISH ecosystem abundant U94/58 140L/s at - eel habitat showed little variation with flow for both and (2006) Teviotdale Option 3: MF 110 Option 1 species most work bridge L/s -common bully habitat optimal 250 – 300 L/s; inflection done Option 1 would not at 140L/s below SH1 Most recent This option would meet Jowett’s flow -torrent fish & bluegill bully habitat declines linearly Ecan exceed Jowett’s recommendations with flow correspondence recommendations -upland bully habitat greatest 50-100L/s declines with with Jowett has for the Upper Option 2: MF 250 increasing flow after that provided the Waipara river. L/s -“There are unlikely to be any problems with fish following advice passage in the Waipara given the fish species present” Mosley (June 2006) for Option 2 MF 80 L/s This option would page 4 RO3/1 the protection of at White Gorge /just exceed Jowett - “”…an increase in minimum flow would result in a habitat of native above Omihi recommendations proportional increase in available habitat for common fish is 80 L/s confluence. on flow needs bullies, bluegill bullies, and torrent fish.” Page 14 upper river, 200 This option would L/s lower river meet Jowett Option 3: 110 L/s “The magnitude and duration of low flows in specification of 80 MF+ Gap summer/autumn had a major negative influence on L/s for usable fish abundance. In the year when flows were low habitat area for This option meets (<0.05m3/s) the abundances of four out of five fish native fish in the Jowett specification, species were reduced; in the year with the highest Upper Waipara (for provided the gap in minimum flow, only two out of five species were Jowett, large part of the the hydrograph is
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reduced” Richardso upper river from maintained, it would n, Bonnett White Gorge to be exceeded “An instream habitat survey (Jowett 1994) showed that paper Weka Creek). The fish habitat began to decline sharply when flows fell submitted Boby’s stream below 120L/s” to Journal (contribution of of Fish 19L/s at 7DMALF)
Algae periphyton on riverbed perceived to be visually Biology will assist with its offensive. Algae appear unaffected by current contribution. abstractions, and it is unlikely managed changes will have significant effects in the future. Option 1 Extract MF 50 L/s at White Flows below 100 L/s result in slow water velocities and from a Gorge tied to a MF therefore, greater potential for nuisance filamentous NIWA of 50 L/s just above growths to occur. report for the Omihi Environme confluence flow nt would not meet the Southland Jowett specification but through the Upper referring to Waipara. Boby’s the stream flow PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED Waipara (7DMALF 19 L/s) this would be available for Braided Riverbed Birds abstraction from the A Block allocation, and would not PERIPHYTON maintain a 80 L/s flow once All options would abstractions began meet this below the gorge. requirement
Mosley RO3/1 PERIPHYTON
Option 3 would 89
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exceed the
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF requirement.
Option 2 would maintain nearly a Haywood flow of at least 80 et.al. L/s in the upper
UO3/11 river, and would better meet this objective, but not reach it. The Boby’s BIRDS stream contribution would maintain a The river mouth 100 L/s flow until area is the most abstracted below significant habitat on White Gorge. the Waipara river, and has been rated Option 1 would not as high 3 (of meet this objective national to as only 50 L/s international O’Donnell would be protected importance) by (2000) by a minimum flow O’Donnell (2000). in the upper section. Mosley discusses bird habitat requirements and concludes that it is not feasible to judge optimal flow for wading birds in the Waipara without a proper IFIM analysis. However, he did indicate that it is likely that habitat suitability is greatest at flows somewhat below the 7DMALF, which is what is
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proposed.
The critical periods for birds in breed is September through to January/
February, so the lowest summer flows only occur at the time breeding has nearly finished.
He also discuss the beneficial effect of flushing flows (see section h) amenity.
Predation and weed colonisation are also likely to be highly PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED relevant in the Waipara.
Recent work done for Trust power in the Ashburton in 2005 indicates that predation is more significant that the moat effect of providing predator- free islands. This indicates that active management of
predators may be an efficient way of maintaining populations of braided river bed 91
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birds than the effect
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF of flows maintaining braided islands of habitat. “The moat effect”.
Ecan staff can only
conclude that the flows proposed would not appear to have adverse effects on bird populations, and the flushing flow rule will be of assistance, and direct management of bird predators and weeds could assist bird populations.
(c) mauri mahinga Mauri strongly correlated to river flows. Larking/ Ki uta ki tai KI UTA KI TAI KI UTA KI TAI kai Ngai (mountains to Tuahuriri the sea) Both option 1, 2, Staff report Runanga Mauri assessed and 3 maintain evaluates that UO1/61 as poor or flows in upper river. bottom section of worse Jan/Feb Option 3 best meets river is naturally this requirement as dryat or slightly it is closer to below 7DMALF 7DMALF and conditions. exceeds Jowett (2006) Chater’s (2002) requirements, work indicates a flow followed by options losing reach below 2 and 1 in that Teviotdale and this order. has been confirmed Waipara a well known Mahinga Kai source for eel and in subsequent Ecan whitebait gauging in 2006.
Zygadlo- Greater than 60 Ecan staff view is
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Karana lLs at Stringer’s that setting a and Ngai Bridge, and 150 MAURI minimum flow to Tuahuriri L/s at maintain Runanga Teviotdale, Option 3: 110L/s connectivity is RO4/01 plus: impracticable, and Best Mauri option not achievable for
1. seasonal as it is closer to low summer flows. It variability 7DMALF would need to be set 2. winter/ at such a high level summer freshes Option2: 80 L/s and would 3. Fish disadvantage passage Mauri better with 80 current consent 4. Maintain L/s than option 3 holders. It also has medium floods particularly in late no real ecological freshes of >8 summer. benefit. (Jowett has m3 concurred with this Option 3: 50 L/s view).
Mauri not as good It is however, as 80 L/s. accepted there is a PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED (N.B the flow cultural benefit in difference would not connectivity, and be discernable by when flows are eyeballing river sufficient, they will according to ECAN flow to the lagoon, hydrologists) and with high 8-10 cumec flows, opens the mouth at periodic intervals. Opening the mouth is important to the life supporting capacity of native fish and the aquatic
MAHINGA KAI ecosystem.
See comments on native fish re Jowett Seasonal variability (2006) for Upper provided by winter 93
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Waipara. and summer B
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF Blocks (with split Seasonal variability hydrographs.), flood provided by flow protection rule Summer and winter (see h) Amenity), B Blocks (with split and Abstraction hydrographs.), flood caps .Also a zero B
flow protection rule block allocation see h) Amenity), January to April will and Abstraction ensure that bed caps drying is not exacerbated by abstraction (NRRP Policy 3 (2) e).
MAURI
Provided the hydrograph gap is maintained, there is little difference between options 2 and 3 at flows above approximately 300 L/s.
See also comments on e) natural character.
Waipara River an Ngai Tahu Claim Settlement Act NTSCA Ki uta ki tai STATUTORY STATUTORY (NTCSA) Statutory Acknowledgement Area. Schedule (mountains to ACKNOWLEDGEM ACKNOWLEDGEM (Waipara is a reference to fish caught in the rivers.) the sea) ENT ENT
Urupa Greater than 60 Covered and Covered and Zygadlo- L/s at Stringers discussed in staff enclosed in staff Pa site and middens near mouth Karana Bridge, and report and in report Urupa near Teviotdale and Ngai 150 L/s at Zygadlo-Kanara Tuahuriri Teviotdale, (2004) In terms of wahi
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/taonga Rock art sites at Mt Donald run, North dean, South Runanga plus: In terms of wahi tapu and taonga, dean, Pyramid Valley. RO4/01 tapu and taonga, best option is option Several rock art sites in Weka Pass, Timpendean, and 1. seasonal best option is option 2 as 7DMALF is Sandhurst. variability 3 as 7DMALF is what the river 2. winter/ what the river normally runs to in Tauranga Waka (canoe landing) site north end of summer freshes normally runs to in low flows, followed
lagoon. 3. Fish low flows, followed by option 3 then passage by option 2 then option 1. Taonga Species option 1. (6 Fish Species present)
TAONGA SPECIES Ngai Tahu PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED Claim TAONGA SPECIES Taonga species Settlement covered in staff Act Taonga species report and Jowett’s covered in staff 2006 advice to report and Jowett’s Ecan. 2006 advice to Ecan. Specific Options 2 and 3 advice not meet that addressed for upper specification. river, but native fish Option1 does not. flow specifications provided by Jowett (2006).
(e) natural Mosley As for Fish NATURAL NATURAL character RO3/1 (110L/s) CHARACTER CHARACTER
In terms of natural Options 2 and 3 character, best maintain 250 L/s in 95
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option is option 3 as the river where the
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF 7DMALF is what the MALF is 398 L/s or river normally runs greater. to in low flows, followed by option 2 Option 2 slightly then option 1. better due to no abstraction between
110-160 L/s that option 3 would have. However, that is only likely in a 1:20 year event.
See comments on Mauri. (f) natural features Scenery Mosley As for fish 110 NATURAL NATURAL landscape -“There are few places where the Waipara itself would RO3/1 L/s FEATURES FEATURES be the focus of attention.” Page 39 -“For the casual car-borne onlooker, there are few See Natural See Natural viewpoints of the Waipara system…”page 39 Character and Character and - “In comparison with other NZ rivers, and bearing in Native fish Native fish mind the scenic attributes that members of the public Comments Comments seem to value, the Waipara likely would receive moderate scores. Page 38 (g) significant Natural summer low flow regime does not provide Mosley 110 L/s TROUT TROUT habitat trout good habitat for trout thus not a significant habitat for RO 3/1 salmon trout. No salmon present. Upper reaches above Option 3 would be Option 2 irrigation areas may contain some trout. Tierney et. best as 110 L/s Upper River is not a good habitat for trout. The Al. 1987. closest to 7DMALF. 250 L/s would weighting given in the upper river should reflect this exceed this situation. Option 2: 80 L/S requirement. Lower River minimum flow at 7DMALF (398L/s) would would be better be optimal. than option 3. Option 3 would meet this requirement and the split in the hydrograph would protect flows between 160 and 300 L/s, provided
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allocation managed. (h) amenity White bait: minor use when flows suitable. Mosley Maintain FLOOD FLOWS FLOOD FLOWS RO/3/1 medium floods freshes of See flood flow See flood flow >8 m3 protection rule of protection rule of delay on takes for delay on takes for
12 hours when flow 12 hours when flow of 8 cumecs of 8 cumecs reached at White reached at White Recreation: Gorge. Gorge. low use for gorges in winter for water- based recreation Mosley as for fish 110 L/s RECREATION Low level of use for off-road vehicles RO/3/1 RECREATION Swimming Not met with option Option 3 best as one. higher flows for recreational Exceeded by option swimming in deeper 2 with a 250 L/s pools. minimum flow
PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED Option 2 at 80 L/s Met by option 3 with better than option 1, a minimum flow of but objective not 110, and a gap in fully met. the hydrograph.
Option 1 inferior to option 2.
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OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW PROPOSED ONWAIPARA RIVERANDTRIBUTARIES REPORT STAFF 12.7 Appendix 7 - White Gorge flow exceedance percentiles: October to April and May to September
Flow exceedance for the Waipara River at White Gorge (site number 65901) From 1 March 1988 to 20 June 2006 Flow L/s
Flow exceedance percentiles for January
0 1 23456789 0 280153 25972 10824 5804 4031 3124 2657 2333 2117 1869 10 1672 1469 1328 1198 1085 1014 964 924 864 822 20 791 757 717 672 620 593 573 540 510 486 30 466 448 433 417 400 386 371 357 344 332 40 320 309 298 289 279 268 252 239 226 218 50 211 204 198 194 190 187 183 179 175 171 60 166 162 158 154 149 146 143 140 137 134 70 131 128 125 121 117 114 110 106 102 99 80 96 94 91 89 86 84 82 79 77 74 90 70 66 62 58 54 50 45 40 35 29 100 24
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Flow exceedance percentiles for February
0 1 23456789
0 47100 5412 3138 2288 1926 1666 1495 1321 1204 1111 10 1046 985 928 872 816 761 699 657 625 601 20 577 560 540 520 504 483 464 442 424 411 30 397 383 370 360 349 334 325 314 303 293 40 284 277 266 257 249 240 229 219 209 201 50 195 189 184 180 177 173 170 167 160 156 60 150 144 137 132 129 125 123 120 117 114 70 111 107 104 102 99 97 95 93 91 89 80 86 83 80 77 74 71 68 65 62 57
PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED 90 51 45 40 36 34 32 30 29 27 25 100 23
Flow exceedance percentiles for March
0 22822 9280 6471 4600 3348 2719 2187 1936 1592 1228 10 1005 856 754 660 614 562 526 494 475 456 20 438 425 409 390 373 356 345 338 331 321 30 313 306 299 292 285 278 273 267 262 256 40 248 242 235 229 224 219 214 210 204 198 50 193 189 185 180 175 171 165 160 156 153 60 149 145 142 138 135 132 128 125 122 118
70 114 112 109 107 105 102 100 98 96 94 80 92 90 88 87 85 83 81 79 77 75 90 73 70 68 64 62 60 58 54 47 31 99
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STAFF REPORT ON WAIPARA RIVER ANDTRIBUTARIES PR ON WAIPARA RIVER STAFFREPORT Flow exceedance percentiles for April
0 1 23456789
0 53673 8287 5829 4626 3821 3293 2943 2658 2438 2255 10 2111 2017 1918 1778 1596 1440 1297 1184 1135 1085 20 1034 979 941 899 867 835 805 779 756 728 30 700 659 639 616 598 584 572 558 546 537 40 524 514 502 487 472 462 453 446 439 433 50 426 420 411 403 393 384 376 370 361 347 60 326 297 285 267 252 242 228 217 210 202 70 197 192 188 185 182 178 175 170 166 162 80 157 153 149 143 135 120 114 102 97 93 90 91 89 86 84 82 80 77 72 67 61 100 50
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW OPOSED Flow exceedance percentiles for October
0 1 23456789 0 105761 24016 17532 14288 12632 10925 9956 9074 8324 7829 10 7346 6875 6561 6268 5921 5644 5409 5217 5031 4847 20 4690 4549 4447 4328 4197 4073 3956 3822 3712 3595 30 3478 3365 3275 3178 3072 2977 2886 2798 2724 2638 40 2545 2467 2401 2340 2293 2249 2207 2161 2115 2074 50 2027 1971 1905 1840 1799 1748 1706 1656 1605 1561 60 1515 1470 1424 1383 1342 1303 1269 1237 1205 1176 70 1142 1113 1090 1067 1044 1023 1002 983 960 942 80 924 903 877 855 826 798 772 749 720 688 90 664 640 613 593 577 562 542 528 512 491
(NOT COUNCIL POLICY) (NOT COUNCIL AND TRIBUTARIES REPORT ON WAIPARA RIVER DRAFT STAFF
100 419 Flow exceedance percentiles for November
0 1 23456789 0 89557 23016 16193 13072 10132 8677 7717 6837 6165 5423
10 4805 4340 3752 3339 3051 2822 2583 2400 2264 2163 20 2073 1975 1871 1790 1720 1672 1604 1552 1511 1454 30 1401 1349 1298 1259 1233 1203 1173 1145 1115 1085 40 1058 1038 1019 997 977 958 940 923 905 885 50 868 853 836 817 795 779 763 745 729 717 60 705 694 680 666 653 642 630 618 606 592 70 578 562 543 524 510 499 488 477 468 460 80 451 442 432 422 413 404 396 387 378 368 90 354 342 330 315 304 290 273 253 228 198 100 147
PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED Flow exceedance percentiles for December
0 1 23456789 0 311121 11472 7430 5589 4725 4106 3685 3385 3084 2891 10 2717 2534 2344 2201 2049 1929 1817 1716 1642 1573 20 1525 1470 1413 1368 1310 1237 1172 1130 1094 1061 30 1032 1003 970 944 914 875 830 794 765 738 40 718 699 686 669 639 615 588 568 553 537 50 519 502 490 481 467 454 440 420 405 392 60 375 357 343 329 315 300 288 278 269 262
70 253 245 237 230 222 213 205 197 189 182 80 174 169 164 160 154 149 144 138 132 125 90 120 116 112 108 102 96 89 82 74 65 100 55 101
102 (NOT COUNCIL POLICY) COUNCIL (NOT
DRAFT Values in the exceedance table are not exact. They are good approximations based on linear interpolation of 2000 classes.
STAFF REPORT ON WAIPARA RIVER ANDTRIBUTARIES PR ON WAIPARA RIVER STAFFREPORT Flow exceedance for the Waipara River at White Gorge (site number 65901) From 1 March 1988 to 20 June 2006 Flow L/s
Flow exceedance percentiles for May to September
0 1 23456789 0 366223 41757 28879 21395 17471 15210 13473 12178 11080 10269 10 9559 8934 8401 7904 7491 7122 6781 6433 6132 5867 20 5609 5369 5132 4917 4720 4527 4346 4192 4027 3867 30 3727 3601 3470 3341 3216 3105 3010 2914 2825 2747 40 2669 2595 2516 2427 2338 2258 2185 2118 2056 1995 50 1935 1879 1825 1771 1717 1666 1617 1570 1526 1481 60 1436 1389 1341 1293 1246 1204 1165 1134 1098 1062 70 1029 996 962 929 894 857 823 787 751 715 80 677 642 611 586 561 537 515 493 472 451 90 430 408 387 364 334 294 259 213 172 137
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW OPOSED 100 73
Values in the exceedance table are not exact. They are good approximations based on linear interpolation of 2000 classes.
12.8 Appendix 8 - Abstractions
Water Permits Consented take L/s Volume Current Need m3 per Min s Min day Flow L/s Flow unless stated Surface Groundwater Permit No. Holder water Max Rate SDE Upper Waipara CRC920587 Maungatahi 50.0 4320 60 SB (I4) Farm Ltd CRC920588 Rangatahi 38.0 3280 60 SB (I4) Downs Ltd CRC940238.2 NZ Vineyard S-D 13.0 1140 50 WG (I2) Estates J-A 6.5 570 M-A 26.4 2280 CRC940475.4 Fiddlers Green O-M 3.0 130 O-M 50 WG Wines Ltd J-S 12.5 540 J-S CRC980403.1 NZ Vineyard 21 10.2 1814 Y (I2) Estates CRC992499 G Renowden 1 0.6 (I2) CRC000546.1 B A Chapman 7.7 60 SB (I4) CRC002019 Hurunui DC 4.4 1.7 190 (I2) CRC010463.1 P J & M P J-S 12.5 1080 65 WG (I2) Smith & Long O-M 3 260 CRC012177 Maungatahi 22.7 1961 50 WG (I2) Farm Ltd CRC012868 B A Chapman 5.4 3.9 467 Y (I2) CRC020962 Xenophon Ltd6 As per 260 O-M 50 WG (I4) 9402475.2 1080 J-S CRC021176 Tutton, Sienko, 22.2 17.9 Max dam 50 WG (I2) & Hill 32,000 M3. CRC030339.1 M&SE Porter 5.0 60 SB (I4) CRC063391 Greys Road <1 L/s CRC063394 Ltd (summer CRC063397 storage) (I2) I2 Current: I4 Continued use as per s124 RMA: SB Stringers Bridge WG White Gorge Upper Waipara – pending applications CRC950255 Maungatahi 38 Farm Ltd Mr & Mrs M CRC041892 Orr 9.6 Perron Developments CRC051276 Ltd 200 Weka Creek CRC920803C. Weka Irrigators 820 28 3 Ltd Pending upgrade CRC920803C 1080
6 Note that the Fiddlers Green and Xenophyon takes are non concurrent, and cannot be exercised separately.
DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME 103 (NOT COUNCIL POLICY)
Water Permits Consented take L/s Volume Current Needs m3 per Min Min day Flow Flow unless L/s stated Surface Groundwater Permit No. Holder water Max Rate SDE Lower Waipara
Home Creek CRC011833.1 AC Gould O-A 15 7560 per 10 21 days CRC040488 M-S 55 57 CRC040279 Hutt Creek M-S 40 57 Vineyard Ltd
Omihi Stream CRC900760B. P J Pollard & 3.3 Y 5 Others
CRC916346A EM Savill 1.4 120 - CRC032147 Glenray Farm 25 2052 120 at Ltd Omihi Confl. CRC011937 KW 26.25 32130 per 57 at Stackhouse 17 days Baxters CRC011938 1 Y
Omihi Irrigation 7.3 Y CRC060598.1 Scheme P’ship
Omihi Stream - Pending CRC041657 Pernod Ricard 45 CRC041613 Eaton 1.4 CRC040848 Muddy Water 18 Ltd
Lower Waipara mainstem CRC 040492 R and W Croft 36 110 CRC 040869 IM and CC 45 A-N 1300 110 Donaldson 28 O-M 1210
104 DRAFT STAFF REPORT ON WAIPARA RIVER AND TRIBUTARIES PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME (NOT COUNCIL POLICY)
(NOT COUNCIL POLICY) (NOT COUNCIL AND TRIBUTARIES REPORT ON WAIPARA RIVER DRAFT STAFF
12.9 Appendix 9 - Number of days of partial or full restriction for a 50, 80, 110 minimum flow and a 173 L/s allocation block.
Reliability of supply for Waipara Abstractors using available historical flow data for Waipara at White Gorge
Number of days of partial or full restriction using a minimum flow of 50 l/s for the period February 1988 to April 2007 based on Waipara River flow at White Gorge and 173 l/s allocation block
January February March April October November December total restriction restriction restriction restriction restriction restriction restriction restriction 75- 75- 75- 75- 75- 75- 75- 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 25- 50- 75- none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 0-25% 50% 75% 100% full 1988 X X X X X X X X X X X X 2 5 19 5 0 0 4 8 12 6 0 0 31 0 0 0 0 0 27 3 0 0 0 0 4 1 2 4 20 0 68 17 33 15 20 0 1989 4 0 1 3 23 0 9 4 6 9 0 0 2 2 2 16 9 0 7 6 16 1 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 114 12 25 29 32 0 1990 12 1 3 13 2 0 2 4 6 9 7 0 10 1 3 5 12 0 5 2 0 16 7 0 31 0 0 0 0 0 30 0 0 0 0 0 17 5 4 4 1 0 107 13 16 47 29 0 1991 7 2 7 10 5 0 14 1 3 3 7 0 10 8 7 6 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 153 11 17 19 12 0 1992 31 0 0 0 0 0 16 5 4 4 0 0 6 6 4 14 1 0 0 17 13 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 145 28 21 18 1 0 1993 21 8 2 0 0 0 25 2 1 0 0 0 17 14 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 185 24 3 0 0 0 1994 31 0 0 0 0 0 28 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 23 4 4 0 0 0 204 4 4 0 0 0 1995 12 5 13 1 0 0 6 5 9 8 0 0 10 7 6 8 0 0 26 0 0 4 0 0 31 0 0 0 0 0 30 0 0 0 0 0 23 8 0 0 0 0 138 25 28 21 0 0 PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED 1996 8 8 6 9 0 0 18 2 2 2 5 0 17 8 4 2 0 0 27 1 2 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 10 6 10 5 0 0 141 25 24 18 5 0 1997 21 3 7 0 0 0 24 0 0 4 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 26 1 3 0 0 0 0 0 14 14 3 0 163 4 24 18 3 0 1998 0 0 0 4 18 9 0 0 0 0 0 28 0 0 3 4 13 11 0 0 0 4 26 0 31 0 0 0 0 0 30 0 0 0 0 0 19 3 3 4 2 0 80 3 6 16 59 48 1999 0 0 0 0 9 22 2 0 0 0 1 25 22 1 8 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 146 1 8 0 10 47 2000 31 0 0 0 0 0 13 3 3 6 4 0 19 0 0 3 9 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 19 1 4 7 0 0 173 4 7 16 13 0 2001 0 2 10 10 9 0 0 0 0 1 27 0 0 0 0 0 27 4 0 0 0 0 30 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 92 2 10 11 93 4 2002 31 0 0 0 0 0 28 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 212 0 0 0 0 0 2003 19 3 8 1 0 0 0 5 5 18 0 0 2 0 1 3 25 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 13 1 8 9 0 0 125 9 22 31 25 0 2004 0 0 3 14 14 0 24 3 2 0 0 0 31 0 0 0 0 0 25 4 1 0 0 0 31 0 0 0 0 0 27 3 0 0 0 0 29 2 0 0 0 0 167 12 6 14 14 0 2005 18 3 5 5 0 0 2 0 2 15 9 0 5 0 5 16 5 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 147 3 12 36 14 0 2006 9 11 3 7 1 0 12 4 5 1 6 0 10 0 2 16 3 0 14 11 5 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 137 26 15 24 10 0 2007 31 0 0 0 0 0 28 0 0 0 0 0 7 4 13 7 0 0 7 4 12 7 0 0 X X X X X X X X X X X X X X X X X X 73 8 25 14 0 0
total 286 46 68 77 81 31 251 38 48 80 66 53 263 56 77 105 104 15 385 53 61 38 63 0 589 0 0 0 0 0 560 7 3 0 0 0 436 31 49 47 26 0 2770 231 306 347 340 99
X = no data available
105
106 (NOT COUNCIL POLICY) COUNCIL (NOT
DRAFT STAFF REPORT ON WAIPARA RIVER ANDTRIBUTARIES PR ON WAIPARA RIVER STAFFREPORT
Number of days of partial or full restriction using a minimum flow of 80 l/s for the period February 1988 to April 2007 based on Waipara River flow at White Gorge and 173 l/s allocation block
January February March April October November December total restriction restriction restriction restriction restriction restriction restriction restriction
75- 75- 75- 75- 75- 75- 75- 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 25- 50- 75- none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 0-25% 50% 75% 100% full 1988 X X X X X X X X X X X X 1 1 6 23 0 0 3 2 14 11 0 0 31 0 0 0 0 0 25 3 2 0 0 0 2 3 1 2 8 15 62 9 23 36 8 15 1989 4 0 0 2 7 18 8 2 5 8 5 0 1 2 1 4 22 1 6 2 10 12 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 111 6 16 26 34 19 1990 11 1 1 5 13 0 2 0 7 4 9 6 10 1 0 5 11 4 4 2 1 0 22 1 31 0 0 0 0 0 30 0 0 0 0 0 13 7 5 2 4 0 101 11 14 16 59 11 1991 7 0 4 9 8 3 14 0 1 3 5 5 7 8 4 10 2 0 29 1 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 149 9 9 22 15 8 1992 31 0 0 0 0 0 13 5 7 2 3 0 4 4 5 4 14 0 0 0 25 5 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 140 9 37 11 17 0 1993 20 2 9 0 0 0 25 0 3 0 0 0 12 9 10 0 0 0 29 1 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 178 12 22 0 0 0 1994 31 0 0 0 0 0 28 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 22 2 5 2 0 0 203 2 5 2 0 0 1995 7 5 8 11 0 0 6 0 8 7 7 0 8 2 9 12 0 0 26 0 0 0 4 0 31 0 0 0 0 0 30 0 0 0 0 0 18 7 6 0 0 0 126 14 31 30 11 0 1996 7 1 10 8 5 0 17 3 2 1 2 5 14 4 9 3 1 0 27 0 1 2 0 0 31 0 0 0 0 0 28 2 0 0 0 0 7 4 7 9 4 0 131 14 29 23 12 5 1997 21 1 7 2 0 0 24 0 0 2 2 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 24 2 3 1 0 0 0 0 2 13 16 0 161 3 12 18 18 0 1998 0 0 0 0 9 22 0 0 0 0 0 28 0 0 0 5 6 20 0 0 0 0 27 3 31 0 0 0 0 0 30 0 0 0 0 0 15 5 3 3 5 0 76 5 3 8 47 73 1999 0 0 0 0 1 30 2 0 0 0 0 26 22 1 1 7 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 146 1 1 7 1 56 2000 31 0 0 0 0 0 14 0 4 2 8 2 19 0 0 0 8 4 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 17 2 2 6 4 0 172 2 6 8 20 6 2001 0 0 4 13 12 2 0 0 0 0 6 22 0 0 0 0 0 31 0 0 0 0 7 23 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 92 0 4 13 25 78 2002 31 0 0 0 0 0 28 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 212 0 0 0 0 0 2003 16 3 5 7 0 0 0 1 5 10 12 0 2 0 1 1 13 14 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 12 1 2 9 7 0 121 5 13 27 32 14 2004 0 0 1 6 22 2 25 1 2 2 0 0 24 7 0 0 0 0 25 1 4 0 0 0 31 0 0 0 0 0 25 3 2 0 0 0 28 1 2 0 0 0 158 13 11 8 22 2
OPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT ALLOCATION AND FLOW OPOSED 2005 17 3 2 8 1 0 1 1 1 2 21 2 3 2 1 5 18 2 28 2 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 30 1 0 0 0 0 140 9 4 15 40 4 2006 8 3 10 5 5 0 11 2 4 4 7 0 10 0 0 6 15 0 9 11 7 3 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 130 16 21 18 27 0 2007 31 0 0 0 0 0 24 4 0 0 0 0 5 3 6 14 3 0 6 1 11 11 1 0 X X X X X X X X X X X X X X X X X X 66 8 17 25 4 0
total 273 19 61 76 83 77 242 19 49 47 87 96 235 44 53 99 113 76 372 23 73 44 61 27 589 0 0 0 0 0 552 10 7 1 0 0 412 33 35 46 48 15 2675 148 278 313 392 291
X = no data available
(NOT COUNCIL POLICY) (NOT COUNCIL AND TRIBUTARIES REPORT ON WAIPARA RIVER DRAFT STAFF
Number of days of partial or full restriction using a minimum flow of 110 l/s for the period February 1988 to April 2007 based on Waipara River flow at White Gorge and 173 l/s allocation block
January February March April October November December total restriction restriction restriction restriction restriction restriction restriction restriction 75- 75- 75- 75- 75- 75- 75- 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 0- 25- 50- 100 25- 50- 75- none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 25% 50% 75% % full none 0-25% 50% 75% 100% full 1988 X X X X X X X X X X X X 0 1 2 6 22 0 1 2 3 15 9 0 31 0 0 0 0 0 19 7 4 0 0 0 1 2 2 2 2 22 52 12 11 23 33 22 1989 3 1 0 0 2 25 6 2 4 4 10 2 1 0 3 2 4 21 3 4 3 13 7 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 105 7 10 19 23 48 1990 10 2 1 1 10 7 1 1 1 7 5 13 8 2 1 2 3 15 3 2 1 1 5 18 31 0 0 0 0 0 30 0 0 0 0 0 12 3 6 4 4 2 95 10 10 15 27 55 1991 6 1 0 6 10 8 14 0 0 3 3 8 4 6 6 4 11 0 28 1 1 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 144 8 7 13 24 16 1992 30 1 0 0 0 0 6 7 5 5 5 0 3 1 4 6 9 8 0 0 2 25 3 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 131 9 11 36 17 8 1993 20 1 3 7 0 0 24 1 1 2 0 0 6 7 14 4 0 0 28 1 1 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 170 10 19 13 0 0 1994 31 0 0 0 0 0 28 0 0 0 0 0 29 2 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 21 1 3 6 0 0 200 3 3 6 0 0 1995 5 3 5 11 7 0 6 0 2 10 6 4 7 3 4 7 10 0 26 0 0 0 4 0 31 0 0 0 0 0 30 0 0 0 0 0 17 3 7 4 0 0 122 9 18 32 27 4 1996 7 1 4 8 9 2 15 1 2 2 1 7 12 2 9 5 3 0 27 0 0 1 2 0 31 0 0 0 0 0 28 1 1 0 0 0 7 2 6 7 8 1 127 7 22 23 23 10 1997 18 3 2 7 1 0 24 0 0 0 4 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 22 2 2 4 0 0 8 0 0 9 14 0 164 5 4 20 19 0 1998 0 0 0 0 1 30 0 0 0 0 0 28 0 0 0 1 5 25 0 0 0 0 1 29 31 0 0 0 0 0 30 0 0 0 0 0 12 4 5 3 4 3 73 4 5 4 11 115 1999 0 0 0 0 0 31 2 0 0 0 0 26 21 1 1 6 2 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 145 1 1 6 2 57 2000 30 1 0 0 0 0 8 4 1 3 5 7 19 0 0 0 0 12 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 14 4 2 3 6 2 162 9 3 6 11 21 2001 0 0 0 5 16 10 0 0 0 0 0 28 0 0 0 0 0 31 0 0 0 0 0 30 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 92 0 0 5 16 99 2002 31 0 0 0 0 0 28 0 0 0 0 0 29 2 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 29 2 0 0 0 0 208 4 0 0 0 0 PROPOSED FLOW AND ALLOCATION MANAGEMENT REGIME REGIME MANAGEMENT FLOW ALLOCATION AND PROPOSED 2003 14 2 5 6 4 0 0 0 1 7 11 9 2 0 0 1 2 26 30 0 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 7 5 1 4 9 5 114 7 7 18 26 40 2004 0 0 0 2 9 20 18 5 2 3 0 0 21 5 5 0 0 0 25 0 2 3 0 0 31 0 0 0 0 0 25 2 2 1 0 0 27 1 1 2 0 0 147 13 12 11 9 20 2005 17 1 2 4 7 0 0 2 0 1 4 21 2 2 1 2 11 13 26 4 0 0 0 0 31 0 0 0 0 0 30 0 0 0 0 0 29 1 1 0 0 0 135 10 4 7 22 34 2006 6 3 5 8 5 4 11 1 1 6 2 7 7 3 0 0 8 13 8 4 10 8 0 0 31 0 0 0 0 0 30 0 0 0 0 0 31 0 0 0 0 0 124 11 16 22 15 24 2007 31 0 0 0 0 0 20 6 2 0 0 0 3 3 2 10 13 0 6 0 3 10 11 0 X X X X X X X X X X X X X X X X X X 60 9 7 20 24 0
total 259 20 27 65 81 137 211 30 22 53 56 160 205 40 52 56 103 164 361 18 26 76 42 77 589 0 0 0 0 0 544 12 9 5 0 0 401 28 34 44 47 35 2570 148 170 299 329 573
X = no data available
107