QUEENSLAND DEPARTMENT OF PRIMARY INDUSTRIES Q086013
IRRIGATION SUITABILITY OF TEVlOT ROOK AREA, BOONAH, SOUTH-EAST QUEENSLAND
N. G. Christianos, K. K. Hughes and A. R, Leverington
Land Resources Branch
QUEENSLAND DEPARTMENT OF PRIMARY INDUSTRIER Queensland Government Technical Report
This report is a scanned copy and some detail may be illegible or lost. Before acting on any information, readers are strongly advised to ensure that numerals, percentages and details are correct.
This report is intended to provide information only on the subject under review. There are limitations inherent in land resource studies, such as accuracy in relation to map scale and assumptions regarding socio-economic factors for land evaluation. Before acting on the information conveyed in this report, readers should ensure that they have received adequate professional information and advice specific to their enquiry.
While all care has been taken in the preparation of this report neither the Queensland Government nor its officers or staff accepts any responsibility for any loss or damage that may result from any inaccuracy or omission in the information contained herein.
© State of Queensland 1986
For information about this report contact [email protected] Queensland Department of Primary Industries Project Series 0086013
IRRIGATION SUITABILITY OF TEVIOT BROOK AREA, BOONAH, SOUTH-EAST QUEENSLAND
N. G. Christianos*, K. K. Hughes* and A. R. Leverington**
Land Resources Branch
* Land Resources Branch, Meiers Road, Indooroopilly, Brisbane 4068 ** Land ResourcesBranch, P.O. Box 1143, Bundaberg, Q. 4670
Queensland Department of Primary Industries Brisbane 1986 ISSN 0727-6281
Queensland Department of Primary IndustrLes GPO Box 46 Brisbane 4001. CONTENTS
Page
SUMMARY 1
i. INTRODUCTION
2. PHYSICAL RESOURCES
2.1 Climate 2.2 Vegetation 2.3 Geology 2.4 Topography
3. LAND RESOURCES SURVEY METHOD
4. SOILS - MORPHOLOGY AND CLASSIFICATION
4.1 Morphology 4.2 Classification
5. CHEMICAL ATTRIBUTES OF THE SOILS 12
5.1 General 12 5.2 Fertility, salinity and sodicity 12
6. LAND USE AND IRRIGATION CAPABILITY 16
6.1 Present land use 16
6.1.1 Alluvial plains 16
Logan River area 16 Mt Joyce area 16 Coulson area 16 Boonah area 17 Coochin Coochin area 17 Croftby area 17
6.1.2 Uplands 17
6.2 Physical constraints on agriculture 17
6.2.1 Drainage 18 6.2.2 Flooding and flood erosion 18 6.2.3 Salinity 18
6.3 Crop - soil suitability 18 6.4 Irrigated land capability classification 18 6.5 Potential of alluvia for irrigation 18 Page
7. SALINITY 25
7.1 Scope of salinity investigations 25 7.2 Salinity sources 25
7.2.1 Kalbar and Boonah areas 25 7.2.2 Alluvia 26 7.2.3 Walloon Coal Measures with scrub vegetation 33 7.2.4 Walloon Coal Measures with forest vegetation 33 7.2.5 Marburg Formation 34
7.3 Preventative measures against salinity 34
8. CONCLUSIONS AND RECOMMENDATIONS 36
9. ACKNOWLEDGEMENTS 37
i0. REFERENCES 38
APPENDIXES
1 Detailed morphological descriptions of soil types
Morphological and analytical data for representative soil profiles
Criteria for irrigated land capability classification for Teviot Brook alluvia
4 Irrigated land capability classes for Teviot Brook alluvia LIST OF TABLES
Page
i. Climatic data summary
. Major distinguishing attributes of the soils and landscapes
. General fertility and ratings in the analysed profiles 13
. Profile chloride (Ci%) levels (oven dry basis i05°C) 15
. Profile sodicity (ESP) levels (oven dry basis i05°C) 15
. Soil limitations, suitable crops and management 19 recommendations of soil types
. Limitation sub-classes for soils 22
. Areas of alluvia in irrigated land capability classes 23
. Data from proline drilling in Teviot Brook alluvia 26
i0. Salinity hazard rating 31
ii. Subdivision of alluvia in Teviot Brook catchment below 31 proposed damsite, applying salinity hazard ratings
12. Salt sources and chloride levels in soils on Walloon Coal 33 Measures
LIST OF FIGURES
i. Locality map
. Profile pH trend 14
. Plan showing locations of piezometers - Teviot Brook 27 alluvia
. Soil chloride profiles from selected proline drill holes, 28 Teviot Brook
. Changes in groundwater depths and groundwater quality from 29 10/83 to 8/84, in holes TBI, TB2, TB3 and TB4
. Changes in groundwater depths and groundwater quality from 30 10/83 to 8/84 in holes TB6, TBI5 and TBI7
SUMMARY
Low intensity soils data and broad salinity data were used to assess the validity of irrigation expansion in Teviot Brook catchment, South East Queensland, from a proposed dam at Croftby on upper Teviot Brook.
The assessment indicates the Teviot Brook alluvia overall have the potential to support this proposal. However the additional area of alluvia proposed for irrigation is not first class irrigation land and includes large areas with shallow watertables. Groundwater quality in these shallow watertables is good. Preventative measures such as improved surface drainage, management to avoid excessive water application and intake, and crop selection to utilise good quality shallow groundwater are recommended in these areas if the proposal proceeds. Measures to improve surface drainage and reduce erosive flooding throughout the general area are also recommended.
1. INTRODUCTION
A request was received from the Queensland Water Resources Commission (QWRC) to carry out a preliminary study of Teviot Brook Catchment to identify areas suitable for irrigation and determine likely problems such as salinity.
The study area comprises approximately 53 610 ha from the proposed damsite near Croftby to the junction of Teviot Brook with the Logan River. Alluvia cover • 5087 ha while the remaining 48 523 ha are low to rolling hills on Walloon Coal Measures and Marburg Formation.
The area is drained by Teviot Brook which rises in the border ranges south of Ipswich and flows in a north-easterly direction to join the Logan River near Kagaru. The upper reaches of the catchment are bounded to the west by Reynold's Creek catchment and to the east by the Burnett Creek catchment. The lower areas are bounded by the catchments of Woollaman Creek and Allan's Creek.
The main centre of the area is Boonah with a population of 1874 (Australian Bureau of Statistics, Brisbane Office, 1981). Boonah is directly connected to Ipswich with service roads to Kalbar and Beaudesert. A locality plan of the area is shown in Figure i.
Figure I. Locality map.
Scale in Kilornetres 0 20 40 60
Caboolture
Lt
Gatton • • IPSWI~ TOOWOOMBA
~STUDY AREA
Beaudesert
• WARWICK
• .::. : _ _: ...... ;_ ~_: _ 2. PHYSICAL RESOURCES
2.1 Climate
Climatic data for the area are summarised in Table i.
The Boonah area generally has a subhumid, subtropical environment with extreme rainfall variability. Annual average rainfall is 868 mm and is predominantly of summer incidence with 72% falling in the period October-March inclusive. Falls are medium-high in intensity, averaging i0-ii mm/rainday.
Summers are warm to hot with maximum temperatures averaging 30°C. Heatwaves can occur in the area, with the highest recorded temperature being 45°C. Winters are cool with average minimum temperatures ranging from 7-8.8°C. Frosts are possible during the months of June-August, depending on location, aspect, height, etc., but are more common during July and August.
Prevailing summer winds are south-easterlies. South-westerlies occur during winter. Wind damage is not common.
Cyclones can cause high winds and heavy rainfall, although effects are much less in this area than in the coastal areas.
Humidity and average evaporation figures are also given.
2.2 Vegetation
There are some marked associations of vegetation, geology and soils, but these are not consistent over the whole area.
Along the banks of Teviot Brook thick stands of river oak (Casuarina cunninghamiana) and weeping bottlebrush (Callistemon uiminalis) can be found, however selective clearing for flood control is reducing their extent.
Much of the alluvium has been cleared for cultivation, however remnants of Queensland blue gums (Eucalyptus tereticornis) tend to be scattered over the alluvial plains.
On the upland areas around Boonah, softwood scrub occurs on sandstones, and brigalow (Acacia harpophylla) on mudstones.
Elsewhere in the catchment these associations are less extensive and narrow-leaved ironbark (E. crebra) forest vegetation occurs over both mudstones and sandstones on duplex soils. Upland sandstone areas to the east are dominated by spotted gum (E. maculata) and narrow-leaved ironbark. cO (~ o0 L~ I"- ~ I~ ~ ~O • "- (~I ,-" ,--
0 ,-- r~ O I~ ~ ,-- -- CO ,--
,-- ,-- ~ ,-- I~
O~ ~ ~ CO • • I~ I~ • 0 CO ~ ~ ,-- 0 ITM If~ ,-- •-- ~ ,-- CO
O~ CO r~ O~ CO ~ • • r~ 0 • 0 •-- O~ ,- U~
O~ O~ CO CO If~ ~ I~ -- • ~r~ 0 • 0 (~ ,--
,-- ~ ~ •-- r~ ~r~ ~ -- ~ CO • ,-- ~r~ ~ ~ ~ ~0 ~0 I~- O~ 0
0 (xl 0 ,-- 0 ~ • • ~ ~ • ,-- 0 l'q ,-- ~ ITM C'4 ~- (~ CO
CO 0 If~ • • ~ ~ -- 0 E r~ t-
L. •-- (~ CO • • ~ 0 • 0 0 O) •-- f~ ,-- 0 0 0
•-- O0 O~ O~ ~ ~ ~ -- cO ,- • 0 O~ 0 CO ,- 0 oO I~
0 O 0 OJ O~ o.-~ I~ ~" r-- ~ • • cO O~ • 0
• • 4.~ c
u? .O 0 ~ 0 ~ ,-- 0 ~0 ~D O. .,-i •-- ('xl ,-- I'q O~ O~
0 S • ,-I 0 •~ A "~ A '~ ~ A E 0 "~ "~ "~ E t~ S- • • • • • • H 0 0 4--' O L O L O ~ 0 • • E • • • E E ~ "~
O ~ 0 ~ E E .,,-4
E tO .,-i .--4
~ ~ ~ ~ ~ "~ "~ ~ • 0 0 m ~ ~ ~ ~ ~ ~ -- ~ ~ c E t- • 0 ~ 0 ~ 0 ~ ~ ~ ~ ~ 0 "~ ~ • ~o ~o ~o o o c ~ ~ ~ e- O O E ~ E c E > ra o O E O E O E ~ ~ ~ ~ • ~ , ~ ,2 > It is difficult to explain the distribution of vegetation on lithological grounds alone because sharp changes in vegetation occur across the area. It is more likely that past and present climate, microclimate and complex hydrology combined with lithology have produced the present distribution of vegetation and soils.
2.3 Geology
The area comprises Jurassic sedimentary rocks intruded by Tertiary plugs, sills and dykes. The sedimentary rocks are folded anticlinally and in the Boonah area strike north-south and dip at approximately i0 ° west on the west limb of an anticline. There are numerous intrusives south from Boonah, with local steepening of sedimentary rocks about plugs and dykes.
The Marburg Formation (Jm) comprises sandstone, siltstone, conglomerate and shale. The overlying Walloon Coal Measures (Jw) comprise mudstone, sandstone, siltstone, shale and coalbeds. There is a strong influence of lithology on soil types in the area, with clay soils developed on mudstones, shales and coalbeds, and sandy soils on sandstone units.
Main developments of alluvia are along the valley of Teviot Brook where softer beds of the Walloon Coal Measures have weathered to broad valleys with fine alluvia. Restricted developments of mainly sandy alluvia occur where the more resistant sandstones of the Marburg Formation have weathered to narrow valleys with steep topography. Coarse colluvia occur on footslopes of steep hills of resistant rhyolite and trachyte intrusives.
2.4 Topography
The topography in the area reflects the geology. More resistant intrusive rocks form the higher steeper parts of the landscape, giving rise to some spectacular scenery. Rhyolite and trachyte plugs and dykes form steep hills with some sheer rock faces. Sills form steepsided flat-topped hills. The syenite intrusives weather to form moderately steep, rounded hills.
The softer Walloon Coal Measures (mudstones and labile sandstones) have weathered to form low rounded hills, and broad alluvial valleys with dominantly fine alluvia. Within these broad alluvial plains the creeks have built up levees, and backplain swampy areas are common at the junction of alluvia and toeslopes of hills.
The Marburg Formation contains quartz sandstone beds more resistant to erosion, and has weathered to moderate to steep hills with minor sandy alluvia developed in steep valleys. Drainage patterns change markedly from Walloon Coal Measures to the Marburg Formation, with main developments of alluvia and potential irrigation lands within the Walloon Coal Measures. 3. LAND RESOURCES SURVEY METHOD
The area was surveyed in two stages• Preliminary work in September and October 1983 was carried out on alluvia and adjoining uplands to identify soil types in the area and assess their suitability for irrigation. At this stage the area was mapped into broad land resource areas based on soils, geology, topography and vegetation using 1:25 000 black and white aerial photos and ground inspections at selected sites.
Investigations into potential salinity problems were carried out using stream sampling and piezometer measurements of groundwater and quality•
These preliminary investigations showed the alluvia had the best potential to accommodate the proposed irrigation expansion. Considerable areas of fertile upland scrub soils occur, but significant soil and water salinity problems were found to be associated with these soils, making them unsuited to irrigation• Accordingly the alluvia were selected for more detailed work with a low intensity soil survey at 1:100 000. Parts of the alluvia were downgraded because of salinity hazard, particularly the local alluvia associated with minor tributaries of Teviot Brook• As a result, soil investigations were then concentrated on the main Teviot Brook and Black Rock Creek alluvia• Field work was completed by March 1984. Detailed descriptions from 140 sites were obtained.
Much of the study area has been previously mapped into soil associations (Paton, 1971). The Paton report covered the area from Boonah to the junction of Teviot Brook with the Logan River. Three soil associations were mapped:
• Bromelton-Fassifern: soils of the river alluvium with little terrace development (prairie soils, black earths and wiesenbodens).
• Logan-Teviot: soils of the terraced river landscape (alluvial soils, minimal prairie soils and solodic soils).
• Bromelton-Beaudesert: soils of the terraced river landscape downstream from Beaudesert (alluvial soils, prairie soils, wiesenbodens, grey clays, soloths and acid gilgaied grey clays)• There was no available information on the soils between Boonah and the damsite.
Soil types were given names of local significance• Where descriptions generally matched, the Paton (1971) or Powell (1979) subgroup name was used. 4. SOILS - MORPHOLOGY AND CLASSIFICATION
4.1 Morphology
There are nine soil types, three phases and six land resource areas identified in the survey area. Detailed soil descriptions from 140 sites were obtained. Five profiles, representative of the major soil types, were submitted for laboratory analysis.
Table 2 lists the major distinguishing features of the soils including a brief description of profile morphology, landscape characteristics and present land use - vegetation. Detailed descriptions including the range of variation within each class are given in Appendix I. Profile descriptions and analytical data for representative profiles are given in Appendix II.
Soils on the upstream alluvial plains are dominated by deep, dark light-medium to medium clay soils (Bell and Warrill) with wet phases of Warrill (occasionally mottled) occurring in drainage lines or backplain areas. Soils on the levees are expected to be lighter textured, although they are not mapped at this scale. In the lower reaches soils are much older with considerable profile development (duplex soils and acid gilgaied grey clays). Small pockets of younger soils (black earths and prairie soils) also occur.
The upland soils are typical of those formed on Walloon Coal Measures with brown or grey clays formed under scrub vegetation while duplex soils (soloths and solodic soils) are associated with forest vegetation. Prairie soils and soloths are associated with the Marburg Formation.
4.2 Classification
The soils have been mapped at a scale of i:i00 000 as associations of soil types. Soil types are groups of soils such that the variation in selected soil features is much less within a group than between groups. Mapping units usually contain a number of soil types but are named after the dominant soil types, or where two soils are codominant, after the two dominant soil types.
Dominant soil types classified into great soil groups (Stace et al. 1968) and principle profile forms (Northcote 1979) are listed on the soil map reference. In addition, sampled representative soil profiles are classified into Soil Taxonomy subgroups (Soil Survey Staff 1975). "0 c c c c c c ,....4 .,,4 o • .o o
0 > ~0 .,-I
• • ,-4
0. 0 O 0 (0 0 EL
o,-.t °,..~ c r- > c > r- > c I c > c e 0 ~ .r-i °,--i 0 c ,.~ (o .c: • 0 m < o. < o. < cl 03 O. '~C o.
c- C c c c 0 • ,.4 (~ •,4 (I~ • ,-4 (%~ • ,-i c0 o.. ~I~ .,-4 ,-4 > > > ,-f > r~ "7 (I] ,--i ,-H 7D c c > > > • e-- > ._J • c • c • c • c --~ 0 ~ 0 -J 0 .A 0 .A 0 .~ 0
,-- 1~7 p~ ~0 ~0 ~0 C'4 0q LL O_ O E 0') O~ 4- O_ c-
O •.~ E .o • L- 0 O "~ (0 ! N -I-, -I-, • °,..4 0 > ..~ _c 0 -I-, O U ,---4 .r-I L O 4-- ,-4 0 ,-4 ~ ~'- O L ,~. ,-~ m • CO • m •
0 0..
0 c "o A c 0 c "O E • • ~ - O. ,-4 0 ~ 0 L c _c E • "O L E 0 7O c .O E C 4- .,4 ~ ,-~ O E 4- -~ • U • °,-4 "O .,'4 O) ,-~ ,-4 ~, O E L c • > , ~ E 0 0 >~ co 0 4~ E e >, C E E (0 .,-I >~ .,4 ~_ ~ O ,--i ~ 0 0 L ,-4 ~, • O U (O -~ • O • r c O -8-' E E O o d O O E 0 U >, • ..C (0 -~ m t.. • ~U ~" °~ ,-4 .O (0 • o,-I L -~ m ~-~ 0 .,4 ,--4 0 ~ "8 >, >, r- .C: ,," .C > E °,4 O E ~ "~ 0 ,-~ E "~ E 0 C~ ~- ~ 0 E 0 ~ 0 •,-i ,,4 ~ E e-- ~, °~ ¢- • 0 ~ o~gS"~ 0 0 • 0 °~..i 4--' U L t. 0 10 0 4-, ~- m m >, U E ~E • E • • _~ ~, ~ .,4 E r- 0 E " '- 0 ~ 0 L.. m O~ 0 ~ 0 c- ,4..- ~; C C .,4 N °r-i o~-I .,.4 "0 .,4 ,4 E 0 ~- r- E "O 0 e- i/) ~ E ,-4 ~" 0 ~ E 0 ..~ 4- t- .~ 10 _,K L_ .O .r.-i ~- 0 O 0 -a :~ "'4 0 .,-.t O O. O • t7 E E "O .~' r7 m 0 E 0 c- °~..~ o,-.t
.~, 0 O. >, L 0 '7 C .0 L L E E 0 0 0.. oO h- 03 O. V" E .0 L • n- 10
"•C C c c c t- c ,u .o .o O • o • ,-'4 • ,-I L. 4-' -s ~-~ ~2 > ~ > ~ > ~o • ~0 • .,-4 "'4 (0 ~-~ • J t~ • • ,-.4 ,.--I ";L -I I_ L 0_ 0 0 0 0 d; 0 0 (.3 0
•~ .r-i °~ > t- > c > c ~ .el > -7 .~ no (D ,-4 0
< o_ 0 • ~0 O. O • m
c c c c 0 ,....4 tTl > ~ > ~ > ~ > 0 4-, e~ e 7O C °,-'4 ~- > • ,-i c- > C CO > > > > L O ~ .-J • c • c • c • c C ,--4 0 ~ 0 ~ 0 ~ 0
Cq u7 ('4 ~ u~ E n t-~ r7
U 0 (O ",~ if) .,.4 ~ 0 E ~- °,~ °,~ C ~O ~- • CO ,-4 ",~ t_ •,-~ L ~- ~-~ 0 0 ~ I_ ~-~ 0 0 m • O~ O o~ ~0 0 ~E CZ O 0 o0 ~o
• E
¢- N ~" E 0 "-~ 0 .~ L 0 U O E E O >, --i 0 ~ >
>~ ,-- 0 C0 "~
c O c ~ E .,-t c ~ O~ O ~-~ O -~ e- >, 000 0 0 0 • "'~ >, ~ 70 • ~..t ffl L. 4-~ '~ c ~ 0 if)
c- ~ 01 L ~ >,, O '--~ • I-- ~- >, > 0 O ~ t- O. .--.t E 0 L ~~ o~ •~ >~ ~-~ ~ O 0 ~-~ • ~ O 0 "~ 0 0 ~'~ ~- ~ .,4 N .~ 0 t_ (0 •. • t- 4-, >~ "O ~" > ~ 0 ~ 0 ~o~ ~o~ O~ (0 O ~ "'-4 •~ ~ 0 t- ,--i "~ E C ,-~ "-~ >
E O O ~ "10 C --~ O U~ >~ E < 0 ~0 - C > O 0 "'4 0 •~ • -,4 0 ~t~ ~ t- .,-i ~ c >~ ~ O 0 o '8 I0 ,"4 ~ 0 O E E O .c ('4 ~-~ t~ ~ O m CO
o,-i > >
0 ,--i r- ,--4 ~0 C 4.~ E ~ 4- 0 L O ~ ~- 0 ,~ 0 ,.--t (/~ .,4 ~ O U O ~- 0 ~0 0 T, O .~ O ~ "~ --
E ,-~ 4-, E E _.1 _1 11
"0 c c 0 0 • ,-4 .r4 0
L 0 ~ ~ ~ ~ 0 O ~ 0 0 0 ~
0 4.-
c ._1
f- ~ C if'/
U (0 .,'4 7O C ~-~ ~" ~-I ~" "~ ~0 ",~ ~0 C :D
._1
co ,--..t if) ,--i co
U ~ U ,-4 ¢'- • ,-..i 0 >~
0 ~- C9
c o,-i c-
• ,-i (o
if) c co • ,-i c~
0 ,--.t 0 >~ L L.
,--t ~E >,
o ,...f f--
"8 ~" r-4 0 oO
c c: c: c L 0 cD 0 0 0 0 ",'4 Cl o,.~ .,-i .,-i CD 4- 4-, >., .1-., 0 4.' 0 L. ~ ~ .Q 4-, 0 ~ 4-J 0 -Q ~-~ ~ ~ ~ -Q -~ ~
o 0 ~ ~ 0 ~ ~ 0 • ~E ~ > oO 3 4- > ~ co > ~E 4- >
~ ~E 2E 12
5. CHEMICAL ATTRIBUTES OF THE SOILS
5.1 General
Five soil profiles, representative of the major soil types, were submitted for laboratory analysis. Profiles were sampled in 0.i m increments and analysed at 0.3 m intervals to a maximum depth of 1.5 m. A bulk of nine 0 to 0.i m surface samples was collected at each site. Analyses and interpretations are as detailed in Bruce and Rayment (1982). The C.E.C. method used was alcoholic at pH 8~5.
Table 3 gives general fertility data and ratings for the 0-0.i m depths of the analysed profiles. Table 4 and Table 5 respectively summarise chloride levels (Ci%) and sodicity levels (ESP) for the six key depths of the analysed profiles.
5.2 Surface fertility
Data in Table 3 indicate that the surface soils have medium to very high levels of the nutrients necessary for plant growth. Naturally high levels combined with long term fertiliser use probably account for this.
Most surface soils have very high levels of extractable bicarbonate phosphorus (P). This P test is more applicable when assessing the phosphorus status of soils with alkaline pH levels (pH >7.4). Total nitrogen and organic carbon range from 0.15-0.29% and 1.8-3.3% respectively. The carbon/nitrogen ratio (C/N) ranges from 9.0-12.6 suggesting that there would be net mineralisation of N on cropping. Total sulphur ranges from 0.029 to 0.066% and a response to sulphur is not expected.
Trace elements (copper, zinc, manganese) are all in adequate supply and no deficiencies are expected.
5.3 pH, salinity and sodicity
For all profiles, soil pH is neutral in the surface becoming moderately to strongly alkaline with depth. A maximum pH of 9.3 at 0.9 m was found in the Warrill profile (S3) (Figure 2).
From data in Table 4, the Bell and Blumberg sites have very low levels of chloride throughout the profile, while the Warrill profiles have high levels of chloride (0.073 and 0.106%) at 0.8 to 0.9 m. These soils are heavy textured, slowly draining, cracking clay soils.
Most analysed profiles are non-saline, non-sodic to 0.9 m. The exception is one Warrill profile which is strongly sodic at 0.6 m (ESP 32) reaching a maximum ESP of 44 at 1.2 m. This high ESP is likely to effect deep rooted crops such as lucerne, reducing yields. 13
0 Z ¸ .~ ~ 4-,
t~ E Ch E ~ E C~ E C~ £~ ~ f~ "~ ff3 -3 ~ -3 ko t- o • ~ O ",~ O ",'~ O "~ O O~ ~._0 --~ to E E E E
""4 0 E E E E
L L) 0 E E E E
0 E E E E E ,'-4 O) 0 •--- ",-~ v-- "~ ,-- "~'~ ~ .,-4 (~ .,"~ • "O 0 E E E E E c-
0 o~ 0 ~" E E E E E E O% O_ "O nO E E E E E 0 _Q
E E E E O U • • "0 • • O) X E E E E r Imm
E E E E E oo o_ E o o_ o. 0 ~- • o ~ d8 ,;~ (D to .,-~
.o O >~ .O E E E L. ~3 o L. O. E E E • E v n-
E
0
0 ¢- ¢- ~- L o) o') o') 0 O i E L L. o L O~ • • E • c- > > > °,..~ --3 U O rn L. J: O. oc- O (o ¢- , >~ ¢- e- c- i- 1- 4-, °,-.4 o,-.4 .,--t .l-i .,.,..i o t- o t- o c- u'~ ¢- ~-~ t- o,..~ ~E
L. L. i_ L. L. • • • • • °r.t > > > > > U
0 c- O o o0 co A A v v
4-, v v o ,-i ,--( ,---I E L L
~ rn m ~ ~ 14
pH 6.5 6.9 7.3 7.7 8.1 8.5 8.9 9.3 0 I I I I I ~
\ ",, \ "1~.~
0.3 -- \ \ \ 0.6 - \ Depth (m) \
0.9 -- / \ / Bell ($4) \\ i Blumberg ( 1,2 • Warrill ($2) I
" " Warrill ($3) ~ i
1.5 J
FIGURE 2 PROFILE pH TREND 15
Table 4. Profile chloride (Ci%) levels (oven dry basis I05°C)
Depth (m) Chloride (C1) % Bell (Sl) Bell ($4) Blumberg Warrill (S2) Warrill (S3)
0-0.1 0.002 0.002 0.002 0.004 0.004 v. low v. low v. low v. low v. low
0.2-0.3 0.002 0.002 0.002 0.011 0.016 v. low v. low v. low low low
0.5-0.6 0.002 0.002 0.003 0.042 0.121 v. low v. low v. low med. high
0.8-0.9 0.003 0.002 0.003 0.073 0.106 v. low v. low v. low high high
1.1-1.2 0.004 0.002 0.003 0.073 0.098 v. low v. low v. low high high
1.4-1.5 0.003 0.002 0.003 0.081 0.076 v. low v. low v. low high high
Table 5. Profile sodicity* (ESP) levels (oven dry basis 105°C)
Depth (m) Sodicity (ESP) % Bell (Sl) Bell (S4) Blumberg Warri11 ($2) Warrill (S3)
0-0.I I .4 I .4 0.5 I .3 5.8 non-sod ic non-sod ic non-sod ic non-sod ic non- sod i c
0.2-0.3 1.6 0.5 0.8 1.9 14.2 non-sod ic non-sod ic non-sod ic non-sod ic sod ic
0.5-0.6 1.5 0.7 0.9 2.9 32 non-sod ic non-sod ic non-sod ic non-sod ic st rongty sod ic
0.8-0.9 1.3 0.7 0.8 5.3 43 non-sod ic non-sod ic non-sod ic non-sod ic st rongly sod ic
1.1-1.2 1.2 0.8 0.7 8.5 44 non- sod ic non- sod ic non- sod ic sodic strongly sod ic
* Sod icity ratings taken from Northcote and Skene (1972) 16
6. LAND USE AND IRRIGATION CAPABILITY
6.1 Present land use
There has been intensification of land use on the alluvial plains over the years• With the steady decline in the dairy industry, there has been a move towards the more intensive cultivation of agricultural and horticultural crops such as soybeans and carrots. These crops are better suited to the well drained soils of the alluvium (Bell and Blumberg).
Areas subject to flooding and excessive wetness (Warrill wet phases) still pose problems and are only likely to be used for high intensity grazing or grain and fodder crops (drainage required)•
For the Teviot Brook area, land use can be divided into: i. land use on the alluvial plains 2. land use on the uplands•
6.1.1 Alluvial plains
The alluvial plains have been further divided into six main areas:
• Logan River area • Mt Joyce area • Coulson area • Boonah area • Coochin Coochin area • Croftby area.
The area with the greatest irrigation potential in the study area commences at Coulson and continues upstream to the damsite. Within this area the valley floor has widened, and consists mainly of black earth soils suitable for most agricultural and horticultural crops with only minor limitations•
Logan River area. Land use in this area is limited due to lack of suitable irrigation water• An area of disease free sugar cane for planting material used at the Rocky Point sugar mill is grown here. Some dairying is also carried out. This area has been previously mapped by Paton (1971) as Bromelton-Beaudesert Association•
Mt Joyce area. Flooding and small areas of soils available for cultivation are limitations which make this area most suitable for grazing on native or improved pastures• Potential for salting also exists. The majority of this area was previously mapped as Logan-Teviot Association (Paton, 1971)•
Coulson area. Current land use is permanent grazing of sown pastures with some grain crops and irrigated pasture• Small areas of seepage salting occur• Flooding also poses a problem• Coulson to Boonah has been previously included in the Bromelton-Fassifern Association (Paton, 1971)• 17
Boonah area. Boonah is the main centre in the Teviot Brook catchment. Choice of crops is limited in this area as irrigation water is of poor quality. Crops with a high tolerance to salinity, such as beetroot, are grown.
Further up the valley towards Mt Alford, grain and oilseed crops are grown.
Coochin Coochin area. Most agricultural and horticultural crops such as carrots, sweetcorn, lucerne and soybeans can be grown. However there is a potential problem with shallow water tables (<1.5 m deep), though water quality is good. To date this has not been a problem. Careful irrigation management would be required to ensure water levels do not rise and cause seepage salting. Some areas are under permanent sown pasture to reduce the effects of erosive flooding.
Croftby area. This is considered the best area in the catchment, because of well drained soils. Most crops could be grown. Current land use is grain crops, lucerne, native and sown pasture.
6.1.2 Uplands
Intensive land use in these areas has decreased, due mainly to the decline of the dairy industry. On the scrub soil areas, some intensive dairy and beef production occurs along with small areas of mainly fodder crop production. There is little usage of irrigation water in these areas because of limited supplies, unsuitable soils or the economics of cropping these areas.
The eucalypt forest duplex soils are less favourable and do not have the same level of capital improvements as the scrub soils. Beef production remains the main industry on these soils, along with minor areas of sown pasture.
Subdivision of the upland areas into blocks with a minimum size of 16 ha is likely to continue, however the economics of croppingthese areasstill needs tobe investigated.
Although some upland areas of fertile soils occur, experience in the Kalbar area has shown that irrigation of these areas is likely to increase salinity problems. The upland areas are not considered suitable for irrigation and were not surveyed in detail.
6.2 Physical constraints on agriculture
Development of the alluvials to more intensive production has been prevented by:
(i) Drainage (ii) Flooding and flood erosion (iii) Salinity. 18
6.2.1 Drainage
A considerable area of valuable alluvia cannot be cultivated because of poor surface drainage, with moderate impeded internal drainage. This is caused by the very gentle slope of the plain and the lack of drains for removal of surface water.
A drainage programme requiring landlevelling and improved surface drainage would need to be implemented to improve soil drainage in the area. The rapid removal of surface water would reduce the effects of prolonged wetness especially during floods.
6.2.2 Flooding and flood erosion
The flooding of the alluvia is a major constraint to development. In many areas of the alluvia, farmers have resorted to permanent grazing pasture in areas subject to inundation e.g. Coochin Coochin area. Many landholders have taken further steps to reduce the problem by constructing levee banks (often unlicensed) or clearing trees from the streambank. This often exacerbates the problem in other areas.
The intensity of the flooding and erosion could be marginally reduced by a co-ordinated drainage network and licensed levee banks placed in strategic situations. Strip cropping is not recommended due to the narrow- ness of the alluvia, crop type and soil variability. No estimate of area affected by flooding and erosion has been made (see 6.5 Potential of alluvia for irrigation).
6.2.3 Salinity
Saline seepages in backplain areas and areas with saline shallow water tables render some land unsuitable for agricultural production. Special land management and preventative measures to prevent further degradation of the alluvia need implementing (see Section 7.2.2 Alluvia).
6.3 Crop - soil suitability
Table 6 lists the major limitations, suitable crops and management recommendations for the soil mapping units, while Table 7 summarises the limitation subclasses.
6.4 Irrigation land capability classification
A modified version of the land classes defined by the United States Bureau of Reclamation (1953) has been developed for Teviot Brook project. Detailed Soils data (Map i) and Salinity data (Map 2) have been combined to produce Irrigated Land Capability (Map 3). 19
Table 6. Soil limitations, suitable crops and management recommendations of soil
Management Soil type Major limitations Suitable crops recommendations
Romani Low plant available Pasture Because of frequent flooding water in A horizon. and erosion, cultivation High water requirement. is not recommended. Best Subject to frequent used as pasture with flooding and erosion. limited grazing to reduce effect of erosion.
Bell Suffers from inter- Most horticultural* Accurate land levelling to mittent waterlogging and agricultural** improve surface drainage. where surface drainage crops Suitable for spray is restricted. irrigation. Preventative Occasional flooding measures against erosive and erosion. flooding.
Blumberg Shallow water table Most horticultural Careful management of would limit the amount and agricultural irrigation water. Land of irrigation water crops levelling is not recommended applied. as removal of topsoil in Occasional flooding some areas would bring the and erosion. water table closer to the surface. Suitable for spray irrigation. Preventat- ive measures against erosive flooding.
Blumberg Saline shallow Salt tolerant Irrigation is not recommended. saline phase water table pasture eg. Rhodes Problem of disposal of grass. Lucerne in saline water. Should be fiood free areas. kept under permanent pasture.
Warrill Suffers from Most horticultural Accurate land levelling to intermittent and agricultural improve surface drainage. waterlogging where crops Application of poor surface drainage quality water may result is restricted. in deterioration of surface Occasional f 1god ing structure. Preventative and erosion. measures against erosive Trafficability. flooding. Suitable for spray or flood irrigation.
Warrill- Restricted surface Pasture, limited Gilgai would require wet phase drainage and impeded grain cropping in levelling. Surface drainage internal drainage. better drained would have to be improved. Occasional flooding. areas. Suitable for spray irrigation. Probably best used as pasture. 20
Table 6 (Cont'd.)
Management Soil type Major limitations Suitable crops recommendations
Warrill Saline shallow Salt tolerant Irrigation is not recommended. saline phase water table pasture eg. Rhodes ProbIem of disposai of grass. Lucerne in saIine water. Should be fiood free areas. kept under permanent pasture.
Kagaru Hardsetting surface Pasture, some Suitable for spray or flood may pose emergence grain crops. irrigation. Gypsum may problems improve surface structure.
Woolaman Hardsetting surface Pasture, lucerne, Requires higher frequency may pose emergence soybeans, disease irrigation than clay soils. problems. free plant cane Suitable for spray or Probably poor general trickle irrigation, fertility.
Waterford Restricted surface Pasture, limited Gilgai would require drainage and lmpeded grain crops accurate levelling. internal drainage. Probably best used as pasture. Couid be irrigated preferabiy by floed.
Kilmoylar Hardsetting surface may Pastu re. Application of gypsum and/or pose emergence problems. incorporation of organic Probably poor fertiiity. matter to improve surface Intermittent perched structure. Fertiiiser watertable above application needed to B horizon. improve fertility. ProbabIy best used as pasture.
Kilmoylar- Poor surface drainage. Pasture Improve surface drainage. wet phase Debil Debil microrelief
Miscellaneous Soil variability and Pasture, most grain Measures taken to reduce occasional flooding. crops. effect of flooding and erosion.
Local alluvia- Irrigation on these Pasture, dryland Grazing or dryland Walloons soiIs may cause seepage cropping. cultivation. Not recommended saiting on the aiIuvial for irrigation. fiats.
Local alluvia- Irrigation on these Pasture, dryland Grazing or dryland Marburg soiis may cause seepage cropping cultivation. Not recommended salting on the alluvial for irrigation. fiats, 2i
Table 6 (Cont'd.)
Management Soil type Major limitations SuitabIe crops recommendations
WaIioon- Soils marginaI for Pasture Grazing. Not recommended forest irrigation. for irrigation. vegetation SIope 3-10% Hardsetting surface wouId pose emergence probiems.
WaIioon- Soils marginaI for Pasture Grazing. Not recommended scrub irrigation. Dryland cropping for irrigation. vegetation Siope 3-I0% High salt IeveIs in subsoiI. Irrigation would ieach saIts out and cause seepage saIting on the alluvial fiats.
Marburg- SIope 10-32% Pasture Grazing. Ensure overgrazing forest Soiis unsuitable for doesn't occur. Could lead vegetation irrigation. to erosion on these siopes.
Marburg- Slope I0-32% Pastu re Grazing. Ensure overgrazing scrub-forest Soils unsuitabie for doesn't occur. Couid lead vegetat ion irrigation. to erosion on these siopes.
* Horticultural crops include: carrots, beetroot, sweetcorn, cabbage (brassicas)
~-~ Agricultural crops include: grain - wheat, barley, sorghum, maize, triticale fodder - lucerne, oats, summer forage oilseeds - sunflower, soybeans heavy vegetables - potatoes, onions, pumpkins 22
Table 7. Limitation subclasses for soils
Mapping unit Limitation subclasses*
Romani f2, e3, shl
Bell w2, f2, e2, shl
Blumberg f2, e2, sw3, sh3
Blumberg-saline phase f2, e2, sw4, sh4
Warrill tl, w2, f2, e2, k2, shl-4
Warrill-wet phase w3, f2, e2, pb3, k2, g2, sh2
Warrill-saline phase w3, f2, e2, sw4, sh4
Kagaru pc3, k2, shl
Woolaman f2, pc2, shl
Miscellaneous f2, e2, shl
Waterford w2, pb3, k3, g2, shl
Kilmoylar pb2, pc3, so3, shl
Kilmoylar-wet phase w3, pb2, so3, shl
* See Appendix 3 for details on limitations and subclasses. 23
Limitation sub-classes derived from soils data are listed in Table 7. These have been combined with salinity hazard ratings as described in Table 10 and Map 2, to arrive at Land Capability Classes.
The classification contains five classes based on increasing limitation to crop growth, difficulty of using machinery and land degradation hazard.
The irrigated land capability classification for Teviot Brook area is shown in Appendix III and descriptions of the land capability classes in Appendix IV.
The classes are:
Class I - Land suitable for irrigation with no or few limitations Class II - Land suitable for irrigation with slight limitations Class III- Land suitable for irrigation with moderate limitations Class IV - Marginal for irrigation with severe limitations Class V - Unsuitable for irrigation.
Three irrigated land capability classes were identified - classes II, III and IV.
6.5 Potential of alluvia for irrigation
Table 8 shows areas of alluvia in irrigated land capability classes II, III and IV.
Table 8. Areas of alluvia in irrigated land capability classes.
Irrigated land Total % of suitability class area (ha) total area
II 1 879 37 III 2 162 42 IV 1 046 21
Total 5 087 100
Areas of alluvia surveyed in detail between the dam site and the Logan River total 5087 ha. An area of 1046 ha of class IV land including areas with high salinity hazard is marginal for irrigation and is not recommended for irrigation development. A gross area of 4041 ha of classes II and III land is considered suitable for irrigation development. Approximately 29% of this gross area could be lost to houses, roads, drainage ways, etc. In addition it is considered that erosive flooding could prevent irrigation of a further 200 ha. Allowing for the above losses the net area of irrigable land is estimated at approximately 2700 ha.
No special studies have been undertaken for this report on the area likely to be lost through facilities on the Teviot Brook alluvia. The figure of 29% used in the above estimates was obtained from data on the 24
Lower Lockyer Valley (Anon 1967). This is considered to be a conservatively safe estimate, since there are fewer roads and houses on Teviot Brook alluvia than on Lockyer Valley alluvia.
Erosive flooding prevents cultivation of some of the alluvia. The area affected by erosive flooding is not the total area inundated. Safeguards such as the dam, artificial levees, and land management will reduce effects of erosive flooding. No special studies of erosive flooding have been made for this report. A conservative estimate of 200 ha maximum affected by erosive flooding and unavailable for cultivation is made.
It is stressed that this irrigable land is not all first class irrigation land, as approximately half of this land has an inherent limitation of shallow watertables. However the groundwater is generally of good quality and parts of these areas are currently being irrigated without evident problems. It is considered that in this area the limitation of shallow good quality watertable can be overcome through careful management and improved surface drainage, without resorting to underground drainage to lower water levels. 25
7. SALINITY
7.1 Scope of salinity investigations
A considerable amount of salinity data is available from ongoing research work in the Kalbar area (Hughes 1982)• This was extrapolated to the adjoining Boonah area on the basis of similar soils, vegetation, geomorphology and geology•
Salinity investigations in the Teviot Brook catchment for this project comprised:
• stream sampling from flowing watercourses • sampling of farm irrigation water supplies • limited proline drilling and soil sampling at selected sites • piezometer installation and monitoring • reconnaissance geological, geomorphological and soils investigations•
Outbreaks of seepage salting were located and used with water quality data from stream sampling to outline salt sources.
Salinity hazard ratings for irrigation land use in this area were developed from these investigations (see Map 2). This is a recently developed method applying data on salt distribution in deep profiles (up to 4 m in this area), water table depths, groundwater quality and soils data, to determine overall risks from salinisation following development• This type of assessment allows salinity problems to be identified in planning stages so that preventative measures against salinity can be taken prior to development•
In addition, salinity assessment was used to screen this area and select the land with best potential to support the proposed expansion• Detailed work was then concentrated on the selected areas. Salinity hazard ratings were then combined with soils data to arrive at irrigated land capability for the alluvia.
7.2 Salinity sources
7.2.1 Kalbar and Boonah areas
In the Kalbar area watertable salting has followed clearing of scrub and forest areas for cultivation and pasture• Salting is more pronounced in cleared scrub areas• The loss of deep rooted vegetation has resulted in additional water from rainfall moving through the subsoil causing rises in groundwater levels• Irrigation of the uplands around Kalbar has increased this effect resulting in numerous saline running creeks and seepages• The uplands around Kalbar have been developed at the expense of adjoining lowlands. Characteristics of intake areas and of impermeable runoff areas have been determined for the Kalbar area and these data can be extrapolated to the adjoining Boonah area. 26
In the upland areas around Boonah intake areas characterised by softwood scrub vegetation on sandstones occur above impermeable areas characterised by brigalow scrub on mudstones. The brigalow areas have high chloride levels in grey clay subsoils, indicating significant salt sources present (see Table 12). These upland areas are currently used for dryland cultivation and pasture, and clearing of trees for cultivation and pasture has resulted in scattered seepage salting occurrences. Irrigation of these upland areas must increase salinity risks by raising water levels, increasing salinisation of Teviot Brook alluvia. A sacrificial approach involving irrigation of uplands at the expense of lowlands cannot be applied in the Boonah area, because saline creek flows will cause deterioration of irrigation water quality in Teviot Brook and jeopardise the proposed irrigation expansion.
Consequently expansion of irrigation is not recommended on the uplands, and should be confined to the alluvia, on those areas where there are no shallow saline watertables.
7.2.2 Alluvia
The alluvia in the main Teviot Brook valley are utilised for irrigated farming and there is considerable potential for expansion of irrigation. Limited testing of the alluvia was done with a proline drill, boring to 4.0 m maximum depth, and installing piezometers. Soil samples from selected holes were analysed for chloride content, and piezometers have been monitored to obtain information on groundwater quality and watertable movements. Results are shown in Table 9 and Figures 3, 4, 5 and 6.
Table 9. Data from proline drilling in Teviot Brook alluvia
Site Hole Hole Depth to Water Salinity of alluvia ppm chloride no. no. depth water (m) quality 0 - 0.5 - 1.0 - 1.5 - 2.0 - 2.5 - 3.0 - 3.5 - m us/cm 0.5 m 1.0 m 1.5 m 2.0 m 2.5 m 3.0 m 3.5 m 4.0 m
I TBI 3.0 1.45 10950 64 259 665 918 804 510 - - I TB2 1.5 1.25 No sample 2 TB3 4.0 1.7(?) No sample 60 400 1055 972 827 600 721 688 3 TB4 3.0 1.2 730 200 132 94 124 131 141 - - 4 TB5 3.0 2.7 46 113 186 150 158 97 - - 5 TB6 2.0 0.67 1080 42 60 97 89 .... 5 TB14 2.0 1.3 830 5 TB15 2.0 0.55 830 6 TB17 2.0 1.15 2230
The samplingprogran~nelocated some areas with high soil salt values associated with shallow saline watertables. These areas have high salinity hazard and should not be irrigated. Other areas were found to have shallow watertables with good quality water, which could lead to some problems under irrigation. These areas need careful management. 27
I
BOONAH nj,,,~ ~ //" TB3 L I I |~ / ", ! TB4,~ / "-J / I ! o Mt. A Iford ~, [_'k"-1~.TB17 i
TB6, TB15/'e t"~
f/~ Dam Site ~,,
¢!
Scale 1:250 000 0 5 10 15kn
FIGURE 3 PLAN SHOWING LOCATIONS OF PIEZOMETERS TEVIOT BROOK 28
0m
t~ ,x-~.._ .
1.0m ~,~ ~.. -;x
T l-- n 2.0m III £3
• a r×," • TB1 % 3.0m ,, x TB3 X i 12 TB4 I ! e o TB6 X%~,. 4.0m ,"X , , , , , 200' 4 6 0 600' 800 1 000 1 200 1 400 1 600 1 800 2 000 ppm CHLORIDE
FIGURE4 SOIL CHLORIDE PROFILES FROM SELECTED PROLINE DRILL HOLES, TEVIOT BROOK 29
Om
1.0m I x-~\'~ .'""%""'-. x
W £3 ./ ss ~ 0 ~-~ 4" ~" --" 2.0m k J/
10/8311/8312/83 1/84 2/84 3/84 4/84 5/84 6/84 7/84 8/84 TIME IN MONTHS
1 000
2 000 ! • I I • I I ~.~ i 3 000 I % I I I E 4 000 I o I oo ~.x,~X-,~ .J I x/ x I >.- 5 000 I I-- I I > I I 6000 ! (O i I £3 I Z 7 000 I O (O I I 8000 I I I I • TB1 9 000 I I x TB2 I I o TB3 10000 I I n TB4 \ /o...t,..~ I 11 000 'V 12 000 10/8311/8312/831/84 2/84 3/84 4/84 5/84 6/84 7/84 8/84 TIME IN MONTHS
FIGURE5 CHANGES IN GROUNDWATER DEPTHS AND GROUNDWATER QUALITY FROM 10/83 TO 8/84, IN HOLES TB1, TB2, TB3 AND TB4 30
0m
•-, ~ --X~ x • '~',,V ,,~'''- - "O~ X,---'-X--
1.0m a
2.0m 10/83 11/8312/83 1/84 2/84 3/84 4/84 5/84 6/84 7/84 8/84 TIME IN MONTHS
E o or) X~xlX 1 000 It"t"- • " ..... •"--'e - --O'~ .-. ~ ......
>.- S S I-- S 2 000 }- o o.....-.-.-o 3 000 z o o 4 000 10/83 11/83 12/83 1/84 2/84 3/84 4/84 5/84 6/84 7/84 8/84 TIME IN MONTHS
• TB6 x TB15 o TB17
FIGURE 6 CHANGES IN GROUNDWATER DEPTHS AND GROUNDWATER QUALITY FROM 10/83 TO 8/84 IN HOLES TB6, TB15 AND TB17 31
The areas of high salting hazard adjoin the scrub Walloon uplands. The areas with shallow watertables appear to be associated with major constrict- ions in the valley alluvia restricting drainage.
Salinity hazard ratings. The Teviot Brook alluvia have been subdivided into four zones on the basis of salinity hazard as shown in Table 10 and Map 2, while Table ii shows area (ha) of potential alluvia using this subdivision.
Table i0. Salinity hazard rating
Criteria Salinity Salinity hazard hazard Salt sources Salt sources Depth to Waterlogging rating in profile in groundwater groundwater
A Negligible Minor Not applicable >2.0 m Minor B Slight Minor Not applicable >2.0 m High C Moderate Minor Minor < 2.0 m Moderate D High Significant Significant < 2.0 m Moderate
Table ii. Subdivision of alluvia in Teviot Brook catchment below proposed damsite, applying salinity hazard ratings
Salinity hazard rating Land use area A B C D Total Total * Negligible Slight Moderate High A+B+C+D A+C
ha ha ha ha ha ha
i. Logan River area 795 - - - 795 795 ii. Mt Joyce area 150 - - 20 170 150 iii. Coulson area 30 195 170 170 565 200 iv. Boonah area 885 30 265 660 1 840 I 150 v. Coochin Coochin area 505 15 740 115 1 375 1 245 vi. Croftby area 350 35 80 - 465 430
i to vi (inclusive) 2 715 275 1 255 965 5 210 3 970 iii to vi " 1 770 275 1 255 945 4 245 3 025 iv to vi " I 740 80 1 085 775 3 680 2 825
* Area best suited for irrigation The ratings determined for Teviot Brook alluvia are based on the following criteria
Rating A. This covers lands with negligible salinity hazard. No significant salt sources occur in soils and no groundwater is present to 2.0 m depth.
The data for TB5 (Table 9) are typical of lands in this rating. Most of the alluvia currently being irrigated is in this category. 32
Rating B. This covers lands with slight salinity hazard. No significant salt values occur in soils or groundwater but soils are frequently water- logged forming a perched watertable because of poor surface drainage.
Lands in this rating occur as narrow backplain areas along most of the margins of the alluvia. There is little cultivation and irrigation of these areas because of waterlogging problems caused by surface runoff.
Rating C. This covers lands with moderate salinity hazard. No significant salt values occur in soils or groundwater, but groundwater is commonly at shallow depth and less than 2.0 m from the soil surface, and frequently in the order of 1.0 m and less.
There is potential for watertable rise and eventual salting in this category. Most of the potential irrigation land for irrigation expansion is in this rating. No salting has been located to date in parts of this area which have been irrigated. There are some indications of minor surface concentration of chloride but adequate leaching probably decreases the risk of salt buildup. Within rating C lands there are variations in salinity risk. Groundwater quality in Black Rock Creek alluvia is poorer than groundwater quality in Teviot Brook alluvia, imparting a slightly higher salinity risk to Black Rock Creek alluvia. The rating C lands also include some lower lying areas with shallow watertables more susceptible to seasonal waterlogging.
Data from TB4, TBI0, TBI4, TBI5 (see Table 9 and Figures 3, 4, 5 and 6) describe rating C alluvia. Data on TBI7 are from Black Rock Creek alluvia.
Rating D. This covers lands with high salinity hazard. Significant salt values (mainly sodium chloride) occur in soils and in groundwater. Groundwater is commonly at shallow depth (less than 2.0 m from the soil surface) ranging up to the surface in seepage salting outbreaks.
There is little potential for irrigation of these lands unless extensive drainage is carried out. The disposal of saline drainage water into Teviot Brook irrigation water supplies would prohibit irrigation of these lands.
A guide to 'significant' salt values is:
- groundwater classed as unsuitable for use for irrigation because of salinity and/or sodicity.
- soils with high or very high values for E.C. and/or chloride, as defined by Bruce and Rayment 1982 (greater than 0.90 ms/cm conductivity and/or greater than 0.06% Cl on 1:5 soil water extract).
Rating D lands have a moderate waterlogging risk, increasing to high risk about actual seepage salting occurrences where groundwater is very close to the surface. Data for TBI and TB3 are typical of rating D lands.
Rating D lands should not be irrigated. This is to protect adjoining high value lands, and to maintain the quality of irrigation water supplies in Teviot Brook. Rating D lands should be kept under pasture, applying relevant vegetative preventative measures outlined in 7.3. 33
7.2.3 Walloon Coal Measures with scrub vegetation
Salt sources occur in soils, rocks and groundwater. Clearing of the scrub vegetation has resulted in additional deep infiltration of water under current rainfall, raising groundwater levels to cause seepage salting and saline creek flows. Softwood scrub areas on labile sandstones have more permeable soils than the brigalow areas, and are the main intake areas. The igneous rocks forming much of the high terrain on catchment boundaries are also intake areas, and springs are common on the lower slopes of these hills. The grey clays formed on mudstone beds support brigalow vegetation, are less permeable, and are high in salts (see Table 12).
Table 12. Salt sources and chloride levels in soils on Walloon Coal Measures
Auger Map Unit Site Description ppm chloride at Hole ., 0 - 25 - 50 - 75 - 100 - 125 - 25 cm 50 cm 75 cm 100 cm 125 cm 133 cm
TB7 Walloon- Cleared brigalow pasture, clay - 215 368 582 - scrub vegetation soil on mudstone
TB8 Walloon- Standing brigalow, brown clay 55 89 306 534 772 928 scrub vegetation soil on mudstone
TB9 Walloon- Cleared softwood scrub, replanted, 51 19 - - scrub vegetation brown clay on labile sandstone
TBI0 Walloon- Cleared softwood scrub, replanted, 32 47 134 134 - scrub vegetation brown clay on labile sandstone
TB11 Walloon- Forest on solodic soil on labile - 67 203 forest vegetation sandstone
TB12 Walloon- Forest on solodic soil on labile 40 450 928 forest vegetation sandstone
Saline creek flows from cleared scrub areas are discharging into Teviot Brook and causing deterioration of irrigation water quality. This was shown by creek water sampling through Teviot Brook catchment in September 1983, with steady increase in salinity of Teviot Brook water through the scrub area. Conductivity increased from 990 uS/cm at Beverly Bridge to 1920 uS/cm in the Coulson area, a distance of approximately 15 km. If the upland scrub areas are irrigated, saline creek flows will increase, seepage salting will intensify, and irrigation of the high value alluvial lands could be jeopardised through increased salinisation of soils and water supplies.
7.2.4 Walloon Coal Measures with forest vegetation
The forest areas have similar salt sources in soil, rocks and groundwater to the scrub areas on Walloon Coal Measures. The soils in forest areas are mainly solodic soils and soloths and are less permeable than the grey and brown clays on softwood scrub areas. Consequently the forest areas are not as sensitive to clearing as the scrub areas.
Forest areas have not been as intensively cleared as scrub areas because the soils have more management difficulties. Under current land use salinity hazard is low. However there is potential for salting if land use is changed and water introduced into the more permeable soils in the forest Walloons. 34
There is considerable erosion in the forest areas, and the area around TBI2 (see Table 12) is particularly unstable. Lower slope areas are eroding through slippage and undercutting of A horizon material, caused by perched watertables developing in the solodic soils and soloths. Removal of trees from those areas increases this instability• Special soil conservation measures should assist in these areas e.g. drains on bottom sides of banks, and improved pastures incorporating salt tolerant grasses to utilise water from the perched watertables.
7.2.5 Marburg Formation
The Marburg Formation includes scrub and forest areas, with forest dominant• The scrub usually occurs on more clayey beds e.g. shales or labile sandstones• Climatic influences also determine vegetation distribution in this area with scrub on wetter areas•
Several occurrences of seepage salting were noted in the Marburg Formation in cleared forest areas, indicating some poor quality water and shallow watertables. The alluvia in the Marburg Formation are mainly sandy, reflecting the more sandy nature of Marburg Formation and the steeper terrain•
As the sedentary soils and alluvia on the Marburg Formation have little irrigation potential no deep drilling for salinity data was carried out. Salt sources and poor quality groundwater can be expected in the mudstones and labile sandstones of the Marburg Formation. Quartzose sandstone beds will be intake areas and should contain only minor salts and good quality water.
7.3 Preventative measures against salinity
Investigations into salinity indicate:
• The scrub areas on Walloon Coal Measures are sources of salinity, demonstrated by induced salinisation which has followed clearing and dryland cultivation of these areas• Salt from the upland scrub areas is already affecting irrigation water supplies in Teviot Brook and soils in the alluvia• If the upland scrub areas were to be irrigated, this salinisation would be intensified.
• The scrub areas on Walloon Coal Measures could jeopardise the proposed irrigation expansion through salinisation of irrigation water supplies in Teviot Brook• Consequently no irrigation of these upland scrub areas should be allowed•
• The alluvia along Teviot Brook and Black Rock Creek, contained within the Walloon Coal Measures, have the best potential for irrigation• Soils are generally suited for irrigation• Limitations in parts of the alluvia are shallow watertables and salinity•
• There is sufficient alluvia to support this irrigation proposal• However approximately half of this land is likely to have limitations of shallow groundwater. The shallow groundwater in these areas is mainly good quality. No salting has developed under current usage of 35
these lands, but the shallow groundwater is a potential problem for irrigation expansion• Since no problems are evident under current practices, careful management with improved surface drainage should be sufficient to deal with this limitation, without resorting to sub- surface drainage.
Preventative measures recommended to prevent salinity in this area are:
• Walloon Coal Measures with scrub vegetation should not be irrigated and should be retained under dryland farming•
• On upland intake areas (areas which had softwood scrub vegetation) the following measures to reduce water intake should be applied where practicable.
- establish deep rooted vegetation such as Leucaena leucocephela (leucaena) - improve water runoff by shorter steeper contour banks
- site water storages so as not to impede overall drainage (e.g. site dams on sides of valleys rather than across valleys)
- ensure water storages do not leak
- encourage salt tolerant deep rooted vegetation along gully lines (e.g. Melaleuca bracteata (black tea-tree)•
• Establish and encourage salt tolerant trees and grasses on toeslopes of scrub areas, and about salt affected areas, to minimise saline water discharge into Teviot Brook• Manage salt affected areas carefully under grazing land use to avoid development of bare areas.
• Improve surface drainage on toeslopes and adjoining alluvia e.g. by constructing grassed waterways.
The emphasis on salt tolerant vegetation and revegetation is to reduce saline water discharge into irrigation water supplies in Teviot Brook, by removing excess water by evapotranspiration. 36
8. CONCLUSIONS AND RECOMMENDATIONS
(i) The Teuiot Brook alluvia overall have the potential to support this proposal for expansion of irrigation through a dam.
Low intensity soils data and broad salinity and groundwater data have been used to make this assessment.
(2) The additional area of alluvia proposed for irrigation is not first class irrigation land, and includes large areas with shallow watertables and good quality groundwater.
Parts of these areas have been successfully irrigated without adverse effects from salinity or waterlogging, so the shallow watertables need not preclude expansion of irrigation in this area. However they indicate a potential problem requiring preventative measures such as improvement of surface drainage, management to avoid excessive water application and intake, and crop selection to utilise good quality shallow groundwater. These measures should suffice without resorting to subsurface drainage.
(3) Expansion of irrigation will necessitate improvements to surface drainage and reduction in erosive flooding.
Accurate land levelling will be required in some areas to improve drainage. A standard approach to clearing trees along watercourses should be adopted e.g. remove trees obstructing water flow in watercourses, but do not remove trees from banks and areas adjoining watercourses. Siltation of the watercourses has resulted in a reduced capacity to handle large volumes of floodwater, thus increasing the area inundated by consecutive floods. Clearing obstructions within the watercourse should reduce siltation.
(4) If this proposal proceeds, additional work will be required to more accurately define boundaries of rating D lands (Warrill and Blumberg saline phases) which are recommended for exclusion from irrigation.
This additional work is necessary so that final decisions can be made from a more precise data base. These decisions may adversely affect some landholders.
(5) Preventative measures against current seepage salting should be implemented to protect irrigation water supplies in Teviot Brook.
These must be vegetative and management methods, as drainage of saline areas would jepordise Teviot Brook water supplies.
(6) Control over water usage so as to exclude irrigation of upland areas of Walloon scrubland is required. Extension work to elaborate this approach and avoid land use issues will be necessary. 37
9. ACKNOWLEDGEMENTS
The authors wish to thank the many people who assisted in the successful completion of this report:
• Dr B. Woods, Mr D. Houghton and Mr W. Steentsma, Department of Primary Industries officers, Ipswich, and Mr M. Hawley, Department of Primary Industries officer, Beaudesert, provided information and comment on land use and soils•
• Drafting section of the Division of Land Utilisation (DLU) drafting the maps and for drawing and photoreducing the tables and figures•
• Soils laboratory staff of the Agricultural Chemistry Branch for under- taking the soil chemical and physical analysis•
• Mr D. Baker, Agricultural Chemistry Branch for assistance in interpre- tation of soil chemical and physical analysis.
• The typists for typing the manuscript and the various drafts for the Interim Report and Final Report•
• Mr R. McDonald and Mr B. Powell for advice and editing of the manuscript• 38
10. REFERENCES
ANON (1967), 'Report on Water Conservation and Irrigation for Lockyer Valley', Queensland Department of Primary Industries, Irrigation and Water Supply Commission.
ANON (1980), 'Teviot Brook Preliminary Investigation', Project Planning Branch Internal Report, Queensland Water Resources Commission.
BECKMANN, G.G. (1967), 'Soils and Land Use in the Beenleigh-Brisbane Area, South Eastern Queensland', CSIRO Australia, Division of Soils, Soils and Land Use Series Number 50.
BRUCE, R.C. and RAYMENT, G.E. (1982), 'Analytical methods and interpretations used by the Agricultural Chemistry Branch for soil and land use surveys', Branch Bulletin QB82004, Queensland Department of Primary Industries Agricultural Chemistry.
Fassifern Centenary Committee (1944), 'Fassifern Centenary Booklet', Committee Boonah.
HUGHES, K.K. (1982), 'Summary Report on Salinity in Kalbar Area'. Internal Branch Report, Development Planning Branch, Queensland Department of Primary Industries.
HUGHES, K.K. (1985), 'Prevention by Prediction' in Vol. ii, Technical papers, Fifth Afro-Asian Regional Conference, International Commission on Irrigation and Drainage, 25 August - 5 September 1985, Townsville.
JOHNSTON, P.J.M. (1979), 'Bremer Catchment Land Degradation Study', Division of Land Utilisation Bulletin No. 40, Queensland Department of Primary Industries.
McDONALD, R.C., ISBELL, R.F., SPEIGHT, J.G., WALKER, J. and HOPKINS, M.S. (1984), 'Australian Soil and Land Survey Field Handbook', (Inkata press, Melbourne).
NORTHCOTE, K.N. (1979), 'A Factual Key for the Recognition of Australian Soils', 4th edition (Rellim Technical Publications: Glenside, S.A.)
NORTHCOTE, K.N. and SKENE, J.K.M. (1972), 'Australian soils with saline and sodic properties', CSIRO Australia, Soil Publication Number 27.
OYAMA, M. and TAKEHARA, H. (1967), 'Revised Standard Soil Color Charts', (Fujihara Industry Co. Ltd.: Tokyo).
PATON, T.R. (1971), 'A reconnaissance survey of soils in the Boonah- Beaudesert district, Queensland', CSIRO Australia, Division of Soils, Soils and Land Use Series Number 52.
POWELL, B. (1979), 'Soils of the Kalbar District, South-East Queensland', Agricultural Chemistry Branch Technical Report Number 16, Queensland Department of Primary Industries. 39
Soil Survey Staff (1951), 'Soil Survey Manual', United States Department of Agriculture, Agriculture Handbook Number 18 (United States Government Printing Office, Washington D.C.).
(1975), 'Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting soil Surveys', United States Department of Agriculture, Agriculture Handbook N~ber 436 (United States Government Printing Office: Washington D.C.).
STACE, H.C.T., HUBBLE, G.D., BREWER, R., NORTHCOTE, K.N., SLEEMAN, J.R., MULCAHY, M.J. and HALLSWORTH, E.G. (1968), 'A Handbook of Australian Soils' (Rellim Technical Publications: Glenside S.A.).
THOMAS, T.C. (1973), 'Shire Handbook Boonah', Queensland Department of Primary Industries.
United States Bureau of Reclamation (1953). MaT~,ual, Volume V Irrigated land use, part 2 Land classification. APPENDIX 1
Detailed morphological descriptions of soil types
Notes:
General: Soil types are presented in the same order as in the map reference on Map I.
Soil profile morphology:
(i) Modal soil profile descriptions refer to the most commonly observed profile morphology. Variations outside the modal range occur less frequently.
(ii) Self mulch:
weak = 1 cm of poorly developed self mulch moderate = 1-2 cm of discrete aggregates breaking to granular peds strong = 2 cm of discrete aggregates breaking to granular peds.
(iii) The soil profile diagram indicates upper and lower depth limits of each horizon.
(iv) Horizon nomenclature: As per McDonald et al. (1984).
(v) Colour: Moist colours were recorded using the Revised Standard Soil Colour Chart (Oyama and Takehara 1967).
(vi) Bleach: An horizon which is 'bleached when dry' is an A 2 horizon that is white or almost so. It has been defined (Northcote 1979) as having the following Munsell notations for a dry soil:
(a) for all hues, value 7 with chroma 4 or less or Value 8 or higher with chroma 4 or less, and
(b) where both the A 1 and the B horizon have hues of 5YR or redder then the value of 6 with a chroma of 4 or less is allowable.
(vii) Texture: As defined in Northcote (1979).
(viii) Structure: As per McDonald et al. (1984).
(ix) Consistence and horizon boundaries: As per McDonald et al. (1984). I-i
o L._
0 ~0 --~ C 0 C
C 0 O ° ,..-I c • • > ~0 > .,-4 L- o_ ,---.t
o O. C,
.,.4 CO C C
.--I
O • o L >, E 0 n ~ C 4-~ ~ .,-I • - C 0 I--
,---.t E 0 • .~ ~, °,.-t 0 t'~ ~ 0 • 0 U7 ~ L- O 0 >- 0 ,-~ 0 ,--4 >- 4- ~- O U o ~-" O, L ~ >,, i o o ~ "o ~o .~ ~ , 4-' c co ',4.- • ,~ O c ~ O O • . .I.o t. ~ 4-' ~ • o >~
,---I L_ O ,m. ,---t . 23 .,.-I • . E C • • -- >, ~" "I~ >~ 0 4..-' C ~0 ",~ ~'~ ~ E ~ C 70 ..0 ,,-.t
C) >- >~ >- >~ -s
0 L. • C ~O • ~0 C 0 if? '~t m
0 O 0 E to E
-0 cO
°,-I 123 I1) ,-...t .,-4
O E oo o 0 0 0 0 E to o 0 0 0 0
LL O-
• ,-4 f'l o ~, T-7
O
O c 0 70 .~ c 4-,
_J O 0 ~L 4-, C~ c • • > I-- O "7 I_ 4-.' O_ (0 13-
O O. c °,-i (0 70 c c o. cO
> O _J
4-' 4-, n- O ,~. O 0 O n U) (0 O ,-- > L ~ >', "O • I-
o,-i ..~ >, ~r~ r~ ~- ~- >- "- ~ O c • ~ O O ,-'4 ).-. ..0 0 u7 P: >, ,.-. >~ ~ -~ ~ c 0 o 0'--4 ~ u7 .- 4-~ . -s ,, 0 --- > ~" 0 (o 0 0 I= ,--~ I'~ ~ ~ ,~ "" "~ O ,'~ ~(~'~ O (13 O,~ "'~ s .c 4-a 0 (0 0 --~ ",4 "0 ~- -7 r7 E L) ~ ~- C~ 4 • ~ • ",~ I- ~ E ~ ¢3 0 E 4- -~ E ~ O ..O c 0 c o o,-i -~ • § g o ~= ~ o o.~ ~ o 2.o d ~ i r'~ ,,-i I,_ (J (;3 0 ,- .-, ~ .~ -2 o ('4 o0 E O if7 ,~ r7 ml ff~ ~ (.9 rnl E E ,-4 O ~ O
O~ O
E .,-4
,--i u E >, 4-, > r" O O O O (D .,.4 E o o I.O E E = 6, I.. •,-I C O3 v' .,.-4 P: .,4 4-' C O,I O,I (D m O 4-' E O .,-i E E 4- O EO o o o O O O O ~ ",~ l_ O O n E o o o o ~ .5 ',-- 09 CO C~ O~I ",r-
>. ,--. r~ O --- >- ,--
~ ,-- •
! ~4~4 r-, , , , if) CO if- "" -jim -~im °J00 . I.~ i..- co 09 ~ .. 0 Lo ,,B r- 00 ~ c N • • O .,..-t O e- c N I,,- if) 0 0 ",~ 0 • ~ N i- ale
• ,-I O. L r- r- O >~ t- O0 I-- L.. L ¢- ,1 ~ ~ ,~ m rn T-8
O ol r" Z~ r" 0 if) c" O -.I 4-' O 0 r" (D > (/) t- if) (D 4-' O~ ol nO (0 • n
O O. (0
"o c- ,--.t r --~ t0 _l
c- O r~ •-- "~ >-~ °,--i tl~ ,-- E I- • ~ I= Z~ ~ ,-~ O~ i~. ~- ~ .~ .,~ I- ,-I .,-4 >- ~0 0 L. O Or) • E --~ • E .- 0 O - 4-' O c~ • L- O • O~ c- --~ >- ",'~ O L- v .- J~ 110 I.. C- n • ~ ,-~ 0 "~ r" E "~ t- O -~ "~ t_ t~ E ~ v L O 123 °- ~ f_00E E ~ "04-, u~ t- O t- co °o O 4-, ~ °,-I °o O >'~ >, "~ o~ ~' o.- 20 o~ ,--t z3 .,-I I-- m e-- E O ~ ~- O U) ~ • if) r" .. r- ..E 4-' E -~ (O 0 ~- ..0 ,~ E °,-..t C~l ~ .,~ • ~ (0 -~ O O CO E m ~ 1301~- 3: .~ .o ~- o0 E 0
0 0 0 E o t~ F:o o~ E ~0 I- O~ CO CXl .,-I m n
-,-'4 ~:oo o O O O O I-- E o o O O O O Q. ~-- CO
b-- CO LO
Ll- -r i i ! 0- r~LO t~ 0 0 t~ LO O- •
°r-~ O. O >~ CO ~-- I-9
o 09 c 0
C 4-,
J 0 m • E 0 , E O L oo 13.. ~oo CXlCO g
o c~ E (I) ",'~ ,-.-I c i! _J > 7 O J
>, ~O _k 4-, 4.-, ~ • o C " O 4-, ~- 0 C "(3 •,4 ,-- 4-~ 0 .- ~ ~ C i._ ,,- o~ ..m • o L ~ ~ ~ 0 ~.~o O .~ -Q .~, (/ NO "=" ~" .~ = 0 4-' • O • c ,,~m o •-~ ~= ~ 0 0 0 c ~ r~ ~ .~ ~ 0
4. °,.-I I~ O x:: ~. • m E ~ ( (..I . >- 0 o . ~8~ ~7 O c- O k 4-' • N I. S ( L O "~ 4-' .,-.t • O O C ~ ~.) -° O~1 ,-- •~1,-- O r" o •
• ,-t • ~ 4-., ~g ~ O ~ c O c o O O O F:: O 1.O o m E Eo e4 co 4-~ E L m O Q. ~.-
.-~ .,-t ~"~ m .r '4- ~o ( I. O O O Q lEO oo o E ~o o O O O o • CO (D O') O,I I.O j ..-I
°,~ >- .o •
~0 --- c- -o c 2c. .' ~ ~ 13. .~ >, 0 • ~ • (0 L "o • ~- cO t'~ t--. t'~ b,- tch ~ >'~ ~ ~. T © ~ o~ o~ o~ n ~c~ O_ i , , , , n >, >, !"-- CO 00 cO LO 0 °° ~ C3 g~ Lf~ LO ~'~ I"-- O0 aO C o,--I • .~O >, ~ C .,4 4-' ~ 0 L. r" ,-...t N 0 O~ c" •,..~ c- .,..~ CI. o ~ ~ E c ,-..-I .,.-t v. O4:~1" 3: '~- APPENDIX 2
Morphological and analytical data for representative soil profiles
Notes:
General: Soil profiles representative of the major soil types are presented in the same order as in the map reference.
Profile morphology: As per notes (ii) and (iv) to (ix) for Appendix i.
Laboratory data: Apart from pH, E.C. and fertility data, chemical data are presented on an oven dry (O.D.) basis.
II-i
0~0~ ...°°
ul
00000 • ..°°° ~ 00000
000~ ~ ....°
.... ° o 00000
o • C"-,I 0 o ~ 00 ~ • ° ° • • • 0 00000
b~ o co ,-i:j 4_1 E~ o-, ZO ..... ~" d r,,I o o o o o
d ~ ~ d:., ;'~ ~.,., ~.,
+ ~ .,.~ .,~
0 0 0 .,-t °~ ,-.-t
°0 r.D 0 b" • ° ,.-.-t ,.-.-t ,-..t .,-.t
~ E ~ E
'it:l o ~ E I-i .~1 ~ ~ .;--i 0
.el b~ ,-.I @ o I o .r-t o~o o 0 ~ .- .~ .~ •
o ,-i ~ ,-~ o .el r~ ~ o ~ o E °+-~
~ ~ .~ o
.o
0 . i , . i ~.,-I ~.p o o o
.~ .~
E o ~~Z~o o ~) ~ ~ ~ ~ o ~ 000000 .i-I o o .~ o . _ _
o Z 0 ~ ~ ~ ~ 0 +; ~ ~.~ .,.~ ,~ r4 ~ m 0 I-i I,.i ~ ~ 0 r4 • ~, ° • • ° • • r~ o
~~o~ C'4 ~ ~ m ~ ...... 0
g~ , , ~o~o I I o o o o e-. o o o 4,,,,goooo ooooo 0
"i/ .c- O 000000 i rn ~ I-2
:3
O (/) Q..
"10 E
-J t- O ,Pi c > O °p} L 13_ :3 (J
O * (~ "IO
> 0 _.1 O •~ O >, I • . >, • 0 ~ 4-~ 4.~ 4 -~ • "10 O ~ c r- - E "-" O p-, -! O -~ t- E t- >, ~- •~ ~ ~- .-, lID O "~ O ,"4 - O i_ >- - "~ U~ c- ~ .~ oo ~" ID~ ,~ >- °- 1~ ,4- n~ E E o • >- -~ L ,~- (/ NI ~ r- E tY ~ U U~ ",'4 O ~ ,~- O • >- ~ .,~ OI 0 "'~ • E -~ ~ ~ 0 O c ,, n- O c r... • ~ "-~ "o cO J: ,-~ O~ 0 L >- O O • O ,--~ "~ ~0 .... 3 O E •..- E L. O~ 4- O O~ • •,,, ~ .,-i • I c E ~ • c- L L 4-, r" r" >- ~, 0 L. / =SN ° 0 Ol .H ~ O O" L ,-- E .r-I °,-.t >~ r~ .~ u~ ~0 ~D r- 0 "~ ~ o-~ n- f- E o~8o °o.. ~ • . >- I~ cO 4- r~ ~I • L _~ o~ o,..~ p,, Q. OI • 4-, • O .,-.i s s f- • -Is E . ~ L L ~ ol '~- • E O N'-~ ~ °,-i o,-.4 ~---. n- • "o O O~ , •-.- (M ..~ L e-- ('~ ('N >- ~1 o'} E ~ V -~o~ggo
O O O N in O O O O E ",~ • O ,~- U') E t. u~ O • E O e~l >~ O t- t- O O ---- r"
OJ
"~ • n- L Or'> - O "O O 4-' ~ c >~ E ,-- • O F: O O O OO OO O O > :3 (",,I 4-' .,~ OO OO O O CO u') T.- E ~" C O E 0 m t- • - ,, N L 0
E ~ .c O O
O ~-" ~ m ,-~ .~,
>, • I"- • ~ i~, ~ t- C O '-'4 ",~ 4-' O
~,~ 7- ...... L 0 0 ~ • o~ o~,~- r~ ~,) L~) LO O Lf) O •-~ C 0 L "~ .... O 4-' ~/~ c" t- N .. • . O O .-~ c .. .oC o.c.ct- N N o.~L O ot- •~ 0 O r~ L .~ ~- ~ .c D 0 ~- •~ O ~0 r- O c- ,-- (,Q r" ('q CQ O ff~ > < m m Z m r~ z-3
@ L.
~J O (~ (~ :3 c O. 0 (3 .,-t c (~ (~ j ..~ O
]_
O O. c 0,M
E~ C E ::3 {3. (~ /
E7 ;:, • PI V' •. ,--I .. (/) ~ r" 0 ::] o o -8 ~; .--" 0 "E~ ~ 0 o. C -~ E ~- 0 --'- ",-~ E 0 X ,-~ (~1 ..Q >~ (~ ~ 0 0 0 • ~ F: .,4 .C ~ ",~ ~ (0 ",-~ .I-' >- -~ E~ -- >- ~ ~.~ o ~ ~ ~ U~ ~= ~ o (0 E i_ "10 Lr~ 0 (J 70 E 4--' 0 ~-- 0::: 0 E ",~ "~ 4-~ (D c rY -- L. .,M o O3 :~ J::: I.~ ",~ ,-~ ~ r~ (~ 0 v o=~°o~ 0 (.) .IS L. (1) 4- 0 ,-- -t~ r- I= -~ C • (~ I ..~ .E ~ (0 (0 L. 4~ ~ ",'4 E~ ~ 70 ~ C .[..
o ,~ (~ (~ 13) • 0 "O ::3 ,--~ ~-~ E 4-~ "E~ t'7 ~ 4-' 4--' E N L.) • ~ • L. ~ ",~ -~' ,~ 0 • "~ (~ .. ,--- .- .L= ~ "O (~ 1'~ ',n 0 "'-~ -O
0 "~) N "O O L. C
{3. o,~ L. o (~ L 0 .. I,- • C
o L. ,-- >- I.~ 0 "~ "'~ L (7 L 0 •-- 031 ,-- E r- ml ey ..Q E .O ~ E c .o E o. 3=
c ~ >- m E .,4 0 O "-" (0 (0 C 0 4- .,4 ~-- E (1)
o O OO E o LOO E O OJ LOCO ~"E~ O ~("~ or) ~-- ] • - >- -~ E 0 ff C~I • 0 l=: >~ C~I ~ 0 ~ L ) OJ E r~ CXl --- 0 "'~ (~ ns >, C
) --- 0 0 ..E L. D. F:oo oo O o 0 0 0 0 • O) F o LOO ~ O 0 0 0 ~" ~ C r- .~ C • -- OJCO ~ r,D 0") Oa LO L (0 4-~ ,-~ 0 "O ('4 c ('4 • ,-
O E ,-~ c n- >., n," :3 ~ -~ E >- L >- E ~ O E ~ (~ O "'~ O E • E: ~ X f= (0 O r-,. O .--- (O O L~ LO Lr) CO o0 --- .,-~ E >~ (D ..,._ I~. I'-.- O0 O0 CO O .-~ L ~3 ~ (~ i,,% M{D -- l].-- I I I I I ~,- L. ~ (~ c L. O C "O O "'~ "~' LL O0 n (3. 70 C ~ '+-' ('0 n 0 C'M l 4- ,- CO i U 03 I >~
E: E~ 0 L. °,,4 0 .,-4 ..Q .,-I L E c c ~'~ _c o~ E L. .,,,4 > CXl CN Cxl > m 0 m m m I-4
O I...
(1)
8 °~-.i
> .,.4 4-~ ,--t
O
"7 0 c .,-i O~ "7 L.
4.-
c Itl
O (1) O I:: -'-- (D c "u .. (N '-4 • o~ O) -o ,/ (0 (O (D c OK 0 "~ - O ~ l ~ E O~ = (0 070 >- E ~- "~ ~- E 0 0 ~ - .- ~ c 0 0 E • .,~ (D 0 "4 ~-
'-4 O~ ~-~ • 0 _C n,,- E ~ >- U 0 >, o "~ (0 >- E ~ ~ 0 >- • ~- ~- 70 (0 "~ "/ (0 .~ 0 0 "7 .,-4 4-. ,-- I~ E >~ ~ ~ I- CO c •-- "~ -0 4- v o "7 _~ (~ C • CO C 0 rJ ~ r"- ..~ ~ ~ L ~-" 70 • "~ C4 "~ (-) L 0 4- C 0 .O ,-~ O) r7 O) (0 c (0 • E "~ -~ ~-- "~ 0 ~ "~ 0 ",4 i_ •~ ~- (0 .- 0 -~ E ~ • ~-~ *~ ~-~ N ~,~ .0 ~ ;_ O ,_a ~- I- 0 E L ~ ~ 0 0 ~ (0 0 -- E E 0 0)(1) ,-~ .. ~ ~ 7 ~ c: .c: c L_ • ,-, 0 L. N (0 • . ~ ~ ~ -~ ....-7 .... N "~ "'~ _~ 0 -0 (D0 ~, c 2 ~ c .. g 0 0 >~ ~ 0 ,-i .,-i l_ 0 .--~ ,-.-4 c- 0
O ~ (0 Q- 0 -~. 0 ~ • -m 0 (0 ~- 0 •,-i c • --,-- (0 I.- (N,-- O~ ~8 E >, •-- E 4- ~o r- 4-, ml ~ O ~- IIII ~ ,-4 E ,-~ ~ ~ ~- O 4.o O ,-4
~ E r-
t¢3 E
O 0 0 0 C'q 4-~ E I'~ o- o- F: 0 CXl 0'~ >-- >, O~ O m e- v ,---.t
~J • > O m C ~ E
..Q ~= .,.4 E oo o o o o o ~ m >.~ .,--I 4--
4-, .- 'T'-- I"-- r- E ---
if) C
O 4-@ • 4.-' t'N r- O --~ O E O CO ~ LO I'-.- i"-- ~0 I I I I I I I Q. > o') o~ D D o 2 c6 c~ c~ oc; o~ ".o O r'- N • , O ,,-,i r- N t_ O ",4 O ,-~ N ~ r- ,.-i ,..-I O ~_ r- f'- i- O .-~ i.. 0 D C 0 70 .,--i c 4-I cO _J 4-, 0 c • 0 i_ 4-' O_ 0. 0 O. C O .*-.' •,,...t (/) .,-4 "~D C ,...-t C D O ._1 0 ~ ~ 0 (1) 1 c I¢~ (- ~ L) -- ~ 0 OI ",~ ,-4 {~ L C .z: "~ .~..~ ...,='. -~"~ ~-~, rY U ~ O ~ • 0 0 L. 0C P: °~ O • n," ~- >~ co .~ c O ~-, ~ >- •-- ,-~ E 70 ~1 ~'- O • ~ O z} U c c N • ,-~ (I} •-- 0 .,4 0 -s 0 "~ "0 0. v ~ .. O ".-" 4-' 70 ~ O ..O L_ C r • ..O E L_ O ~i "" 0 -" • (0 "o E >', ...... ~- ~ ?~ ~ r7 (0 L ~ E U ~D • oo 0 4-' (- (I)I "0 ..0 ,--~ ¢)I C "" 0 ~ @) °,.4 • "~" ~~ ~ • ,'--,, .~Cl 0 ~ "7"I l.~l U c ~, ~, o 2 ~ . .. O o~ ~' L. ~ ~ 0 • i ( OI ""-' ' ~. ~ogo ',~1 ~'~ O .o (_) rnl.C~ ,,~- El-- O E E (0 o F: o o o o r Eoo o o o o o £ E o o o o o o v-- co 0 CO ~ CO CO L 7" i i i I ( L O') D 0 L 0 E 0 0 >, L O) v" I z-6 0 L 0 c 0 70 .,-4 c 4--' _j .~ t- 0 O 4--' O~ .,..t t- • > 0 .,--4 O_ 0 0 o. Itl c ,--t c "-~ .J 110 o~ ,--i -"- 0 0 O~ ~ 0} c ~ 0 0 0 .- L • 0 ~ ~ (7 •~ ~ -I-' 70 -i-' t.. I-- X:::) .C ~ ~ 0 0 ~ ~ • ,-...t (I) ~ c I ~ 0 ~ c ~ ~ 0 .,--t "~ ~1 (~ >~ 0 0 ~ ~ ~ 0 o 01 ,~ 0 •~ ~ ~ ~ 0 0 ~ 0 u) ,-4 .E >- • .E i1) 0 "" ,'- "'~ "'~ (~ 0 0 0 ~ ~ 0 > 03 C ~ 4- o .~-~ 4- o • ,-I -~ E: ~- (U "" L. 0 ~ ~ c ~ E L • ,4 "0 -~ r7 ~ > • . -~ ~ "~ ~ 0 0 .,-4 4-*' 8 n -,-t o -r-I ~£ " o r" L- 0 • r-t -'l "~ •--~ ~ I0 (0 0 C%1~ CO ~ CO N m m "~,£o e> aim m E .c .,~ aim m .~ .c o 0 o o 0 I:= o ~- ) I=o co .,- ) • ,...t 121 CJ ) C~ ,--t .,.-i ) n I=0 0 0 0 0 0 0 o O0 E oo o ~ o 0 o L- CJ LO 0 0 L.. 01 0 0 0 0 0 0 ..r ~,• r-- I'-- r.: r-- u_ i i I I I n 0"-0 CO LO I~ I'~ E C 0 °,.-4 .r.t o~ L u') F-- tO C4 ZZ-2 ~0~ ..... ooooo [.... °°°°0 ooooo tn I::n o f-I 1.4 o , ~ Z -~ O O °°°°0 I.~ 0 -O O ooo0o o u~ cO • . . . . 00 O ,--t o o o o ~o r~ o O t+ E zo • ° . . ° g O ~ ,-I ~1~ ,~ "D 0 ,.o C: 4-I u'h .,-I ul (D ..~ t4.4 ,--I ..~ p~ ~ O ,--.t -,--I -,-.t m .(D ~ .,--I E .~ E E •~ 0 "~ -~I < Ln ¢N C_) • (2) 0") ~ .,-I -,-I ..I-' .r-I C',I ¢x/ ~1 CW. • E E~ • 0 • • 0 -rt E ~J ~J E r,j ~3 .H r-to 00 ~ O O ~ .-p O fi E~ 0 O ,--t o~-~ -,--I 131 ~__~-" rW 0 ,~ ~0 -,I O~ 'D ,~ On ~0 ~O ~0 t~ o 0 0 • • . • ~'H 0 0 0 0 ,-H 01 +~ °~ °~ @ rx ~ ~ o 0 ,H -~ co • t'~ t~ r~ -,-4 ~ gg~ggg > o~0 000000 if3 ~ • U'I ..°... ,--I • ° r"- ° oooooo t~ Z ~.o O C i:~ -,--I N ,e • ~ o ~F 0 0 • C.) ...... 00~• 0 0 0 0 0 0 [:4 L} ~ E E~ E v~ E ~ E E g ~ ~ g ~~00 o IN 1~ (D ¢'~ rw ~ I I I I gg O ,-, g g g OOOOOOogg~ o r"- or.- O 000000 I 1 o_ ~ m E i 11-3 0~ .°... E ooooo r.~ ,-t ~ ooooo ,-.i i~ °o°°. o .,H o ¢N ¢N c,l ,-t ,-.t ,-I ,--I • • ° • • o O O O O O o co c...l r~ + ~ ~ c~ • • • . • o 0 00000 E ~ b~ o ,~ o O ,...-t 4J O r~ ~ O O O O O O o + 1.1-.4 ÷ "~ 1.4 ,--t ~ -,-t ,--t ,---t ,.....i ,..-.t ,.-.t O ~ O ~ >, + ,--t + 03 ~J O O t~ o ,'4 ..~ -,-'t +~ ,-4 ~J ffl ,r,D r~ r..) ,la X2 O • ° ~ O b" ul 4J 1~1 "° ~ ",-t m .,.-t • ,~ ~ 0 0 E~ -~ -,~ (D -,-t E ,~ 0 • -H t:~ ,~ E~ -~ 0 E ..~ O o O E 0 ~ • "o °~ o o~ ~ ~ ,-~ .,.~ ,--t -,-t r~ 0-- -,-t I .~ .,-'t 4~ ~ o 4~ 0 • ,-t 4J 4J -,-t • 0 .~ z~ ~ E~ -,~ ,--i ~.~ .... i -,-t ~ oooo ,-t . °~ ~N o E ¢,1 ~ o O > o~o >t OOOOOO ~ , ° OOOOOO Z S o ~ o ~4 ~J ~ 121 121 c3 m ~ ~ oooo~o • ° .... r~ 000000 r..) m ~ ...... O g~ .° oooo~ e- o IIIItl ,° ~ ~ °° .t- O OOOOOO ~ ,~ m rn 11-4 ..... OOOOO C'4 :~ ooooo • ° ° ° o re) Uc) 0 ~o ~ ,," ~ o • ° . ° ° ~ !ooooo + H ""1 ~ ° r~ "D L~ O ,---I..... O o O o b.0 ~ZO~o ~ Ln • ° ~ ,-.4 ~ ¢"-1 0 4J ~o -~ 0 ,..-t ~ CN C',l ~ uo • ° _~ o P~ 0 ,~ o o ,0 •~ ~4-: I E ~s .CO ~ • O E o (D .. ~ °, o J 00~ ~'~ -~ 0 E [~. ',~ ,-.g ¢:h Oh -,-I ~ ,.~ 0 E~ 4J -,~ rJ'J ~ c~ c~ ~ c~ b~ ~ 0 ~ m .CO 0 .,.-t 0 'lJ "~ ~H 0 CD~., 0 ~0 O .... I • ¢--I I~ o -,4 CU ,--t 12n "~ m +-~ -,-.i ,.~ o °. .. ~ o .,~ ,.D ,-..t ~.D c~ tD ,---i O ,.--i r'N O ~ t ~ H~,~ O O ,--t ,-.t O O > o\o • ° .... O O O O O O ,-..-i Z ,-..t .o = d (11 ,-.-I ,---I ° ° ,...~ 4J :>i -,-I j r---t I 0 o ,--.t • O ° o o ° ° ° e~° ~ O O O O O O • ,--i ,_~ ,---i ~ C3 ~ cO 1.4 t.) 4J ~ M ¢..q U? ~0~0 0 °. ~-~ .° O ~ .. ~_ o ~ ~ °~~ "- ~ i 0000~0 11-5 U'N ,---t, O +-~ ~o~ ..... [fl co • . . ° ° H Z • , . . . E r- oo~ P4 i o ...°. I 0 ,----I H 0 ~.~ t~ I.~ l"~ + ~ t~ ¢xl Cq t~ 0 r~ • ° . ° • ° 0 0 0 0 0 0 n- I 0 U~ r~ t~ 0 ~ 0 5~g ,.-t • ° . . . tD o ~ ;', o• -- ~-~ t~ 0 ~ ~ ~ rnrn 4..1 -,-.t ~ 0 0 0 ca ~ ,---t "H "O ~ E~ 0 ~: • ° ~ m O l,t ~ 0 O~ 0 CD • 0 r~ ~ b7 L~ o~ O N cl ~ • ~ 0 °H 0 • E~ ~ u~ °CO 0 0 ~2 o • > °r-t Z'~ o.t~ ~: .- 0 O~ 0 -,~ n~ ~ ~ ~ c' .~ ~ • O t~ 0 0 .,4 ~.H .... 0~ .i.n o o O O • -,-I • -~ 0 -~a ,H ~ .,-t ~ -H O °~ -~ ~ O -,-t ~1 > oooooo o\O .°.... oooooo ~ v 0 CD CD CD -~-I • z o • o "~ o r--tl 0 .°.°°° C) co D • m CY tm ...... o o o g o oooogg oooo~ e- IIllll 000000 O c-I ,-~ ~ogog o l'il i .,-- APPENDIX 3 Criteria for irrigated land capability classification for Teviot Brook alluvia Capability Sub- class (if Limiting factor Degree of limitation class sole limiting symbol factor) Topography Slopes <1% i tl 1-3% II t2 3 - 10% Ill-IV t3 10 - 32% V t5 Wetness Requires accurate II w2 levelling and storm drains. Requires permanent IIl w3 drainage. Susceptibility No flooding. I to flooding Occasional flooding. II f2 Susceptibility to To reduce erosion to an water erosion acceptable level, require: Simple practices II e2 Intensive practices III e3 Pasture phase IV e4 Shallow water Water table >1.5 m deep I.I sw2 table Water table <1.5 m deep III sw3 (good quality water) Saline water table <2.0 m IV sw4 deep Soil physical i. B horizon or subsoil factors affecting depth. Depth to horizon plant growth of slow permeability. and management 20 - 45 cm II pb2 <20 cm III pb3 2. Surface crust. Surface soils likely to set hard if overworked. II pc2 Surface soils set hard. IiI pc3 III-I Suitability Sub- class (if Limiting factor Degree of limitation class sole limiting symbol factor) 3. Soil workability. Surface soils with narrow moisture range for working. Slight restriction II k2 Moderate restriction IiI k3 Severe restriction IV k4 Microrelief Vertical interval of gilgai <25 cm II g2 25 - 60 cm III g3 >60 cm IV g4 Sodicity Non-sodic II so2 Sodic III so3 Strongly sodic IV so4 Salinity hazard Negligible I-II shl rating Slight III sh2 Moderate III sh3 High IV sh4 Factor interactions There are occasions when there may be interaction between limiting factors. It is proposed that where there are more than two Class III limitations that the land concerned be placed in Capability Class IV. APPENDIX 4 Irrigated land capability classes for Teviot Brook alluvia Class I Land suitable for irrigation with no or few limitations. (i) It is highly productive requiring only fertiliser input under a cropping programme. (ii) It presents no or few limitations to machinery use or choice of implements. (iii) Erosion hazard is low under intensive cultivation. Class II Land suitable for irrigation but with slight limitations to use in one or more of the following categories. (i) Land with some limitations to crop growth requiring amendment(s) to attain satisfactory productivity. (ii) Land with some impediment to the use of cultivation or harvesting machinery which limits the choice of implements or restricts operations, such as wetness and occasional flooding. (iii) Land which under cultivation requires simple conservation practices to reduce soil loss to an acceptable level. Class III Land suitable for irrigation but with moderate limitations to use in one or more of the following categories. (i) Land with moderate limitations to crop growth requiring reclamation or treatment to attain satisfactory productivity. This includes land with a shallow water table frequently at <1.5 m depth, with good quality groundwater and requiring careful irrigation management to prevent water level rises. (ii) Land with moderate impediment to the use of cultivation or harvesting machinery which limits the choice of implements or restricts the conditions and timing of operations. (Waterlogging due to restricted surface drainage and impeded internal drainage). (iii) Land which requires intensive conservation or protective measures to maintain soil loss within acceptable levels. Class IV Marginal land suitable for irrigation but with severe limitations to use in one or more of the following categories. (i) Land on which crop growth would be very poor without intensive reclamation or protection measures. This includes lands with shallow saline water table at <2.0 m depth, with inherent problems on disposal of saline water in Teviot Brook catchment. IV-I (ii) Land with severe impediment to the use of cultivation and harvesting machinery which limits the choice of implements or severely restricts the conditions and the choice of time of operations. (iii) Land which cannot be used safely for continuous cultivation due to excessive soil loss even with conservation measures applied. Cover crops would be required to limit soil loss to an acceptable level. (iv) Land which requires special economic, agronomic and/or engineering studies to show it is capable of reclamation which can ensure sustained economic crop production. Examples of severe limitations are: inadequate drainage, excessive salt, likely secondary salinisation, periodic inundation. Class V Land which is not suitable for irrigation due to one or more of the following limitations. (i) Land whose limitations to crop growth cannot be satisfactorily corrected with existing technologies. (ii) Land with limitations such that cultivation or harvesting machinery cannot operate effectively even after treatment. (iii) Land on which the level of soil conservation works required to reduce soil loss to an acceptable level would unduly hinder farming operations or land that is subject to regular damaging erosive flooding.