Wellington Water Seaview Waste Water Treatment Plant Intermittent Discharge Recreation Effects Assessment
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October 2017 Draft ver 2 1 Rob Greenaway & Associates Wellington Water Seaview Waste Water Treatment Plant Intermittent Discharge Recreation effects assessment Wellington Water Seaview WWTP Intermittent Discharge | Recreation effects assessment Rob Greenaway & Associates 2 Wellington Water Seaview Waste Water Treatment Plan Intermittent Discharge Recreation effects assessment Prepared for Stantec Ltd by Rob Greenaway & Associates www.greenaway.co.nz October 2017 Version status: Draft ver 2: 10 October 2017 Wellington Water Seaview WWTP Intermittent Discharge | Recreation effects assessment Rob Greenaway & Associates 3 Contents 1 Summary ................................................................................................................................... 4 1.1 Introduction .................................................................................................................... 4 1.2 Findings ......................................................................................................................... 5 1.2.1 Recreation activities ................................................................................................ 5 1.2.2 Proposal effects ...................................................................................................... 7 1.3 Method ........................................................................................................................... 8 1.4 Author experience and expertise.................................................................................... 9 2 Literature review - recreation ................................................................................................. 10 2.1 National marine recreation participation ....................................................................... 10 2.2 Regional recreation activity distribution ........................................................................ 12 2.2.1 Shellfish gathering and swimming ......................................................................... 14 2.2.2 Fishing .................................................................................................................. 18 2.2.3 Boating and sailing ................................................................................................ 21 2.3 Terrestrial recreation .................................................................................................... 24 3 Interview summaries by activity ............................................................................................ 26 3.1 Boating ......................................................................................................................... 26 3.1.1 Kayaks, rafts, SUP ................................................................................................ 26 3.1.2 Keelers and launches ............................................................................................ 26 3.1.3 Waka ..................................................................................................................... 27 3.1.4 Rowing .................................................................................................................. 27 3.1.5 Model boating ........................................................................................................ 27 3.1.6 Kite and wind surfing ............................................................................................. 27 3.2 Harvesting .................................................................................................................... 28 3.2.1 Fish ....................................................................................................................... 28 3.2.2 Shellfish ................................................................................................................ 28 3.3 Swimming and wharf jumping ...................................................................................... 29 3.4 Terrestrial ..................................................................................................................... 29 4 References .............................................................................................................................. 30 List of Tables Table 1: Participation locations in natural settings, Wellington (Sport NZ 2015a) ................................... 12 Table 2 :Activities recorded from Estuary Bridge downstream (Greenaway, 2015) ................................ 12 List of Figures Figure 1: Main activity areas - summary ................................................................................................... 5 Figure 2: Sport and recreation activities with the highest participation levels (SPARC 2009b) ............... 10 Figure 3: Shellfish and line fishing sites from Allen et al 2009 ................................................................ 14 Figure 4: GWRC Regional Coastal Plan Coastal Water Classes for Wellington Harbour ....................... 15 Figure 5: GWRC monitored marine bathing sites in and around Wellington Harbour ............................. 16 Figure 6: SLNZ recommended swimming beaches ................................................................................ 17 Figure 7: Surfcasting guide recommendation, Draper & Airey (2012) ..................................................... 18 Figure 8: Boat fishing guide recommendation, Airey (2014) ................................................................... 20 Figure 9: Boat club, club and DOC mooring and ramp locations, Wellington Harbour ............................ 22 Figure 10: Windsurf launch sites ............................................................................................................. 22 Figure 11: Sail racing marks Wellington Harbour .................................................................................... 23 Figure 12: Public access around the Hutt River mouth – Source: WAMS ............................................... 24 Figure 13: Hutt City online GIS recreation areas ..................................................................................... 25 Wellington Water Seaview WWTP Intermittent Discharge | Recreation effects assessment Rob Greenaway & Associates 4 1 Summary This report: . Identifies the recreation activities undertaken in the area potentially affected by the proposed Seaview Waste Water Treatment Plan (WWTP) Intermittent Discharge; and . Reviews the potential effects on recreation of the location of the discharge point south of the Waiwhetū Stream confluence in the mouth of the Hutt River. The bulk of this report describes the relevant recreation opportunities. The effects of the discharge on recreationally-taken fish and shellfish and on water quality are summarised in the relevant assessment reports described in the Seaview WWTP Intermittent Discharges Resource Consent and AEE. These data are not repeated in detail in this recreation report, but relevant factors are reviewed in section 1.2.2. This assessment finds that the proposal has a minor adverse effect on recreation amenity. Adverse effects are limited by: . The low frequency and short duration of unplanned discharges, . The management of controlled maintenance discharges to occur in winter, . Timing of planned discharges to occur on outgoing tides, . The discharge plume to be limited to the true left of the flow of the Hutt River, avoiding effects on contact recreation in a proximate area on the true right around the Sea Scouts facility, . The coincidence of rainfall-related overflow discharges with high (if not higher) levels of background contamination, . Established expectations that shellfish gathering in an urban area with many stormwater discharge points is inadvisable. Health warnings will be required during planned and unplanned discharges along Port Road specific to whitebaiting (during the season) and contact recreation. As stated, during wet weather discharges, the potential for adverse effects are masked by high background levels of contamination in the Hutt River and Waiwhetū Stream, and standard rain-event warnings will remain necessary. 1.1 Introduction Wellington Water is reconsenting the existing outfall in Waiwhetū Stream which is used to discharge treated wastewater when heavy rains exceed the capacity of the system, or if the discharge pipe to the coast at Pencarrow needs maintenance. Rain events mean it is used an average of four or five times a year, and maintenance requirements mean it might operate for a week or so every few years. A preferred alternative location for the discharge has been identified to the south of the confluence of the Waiwhetū Stream with the Hutt River mouth (Figure 1). This assessment considers the discharge as a new activity and reviews effects without the existing discharge in place. An earlier version of this study was used in assessing alternative locations for the new outfall. The assessment area is defined by the marine and river areas where treated wastewater has the potential to disperse to, defined by the 10m depth contour between the Petone Wharf and Wellington Water Seaview WWTP Intermittent Discharge | Recreation effects assessment Rob Greenaway & Associates 5 the southern end of Lowry Bay, and up to the Estuary Bridge on the Hutt River, and the Wainui Road Bridge on the Waiwhetū Stream (the dotted line in Figure 1). 1.2 Findings 1.2.1 Recreation activities Figure 1 shows the main recreation activities in the study area. While fishing and boating were identified as