Development On Lake Flats

Press, Volume CV, Issue 31007, 12 March 1966, Page 8

Development On Lake Flats

Some farmers near Lake Ellesmere may soon be increasing their contribution to New Zealand's farm production. These are men whose land is subject to flooding by salt water and who are now spending considerable sums of money on building stopbanks to protect their country from lake waters and to instal pumps to irrigate this country and flush the salt out of it. These pumps may also be used in reverse to pump off water in the winter months to enable this country to carry stock at this time of the year.

Mr L. W. J. Woods, of; Motukarara. who is one of I these, has spent between £2OOO and £3OOO recently in erecting a 66 chains long stop-] bank facing the lake and also installing a pump. ' Mr Woods is working on an j area of some 200 acres be-] tween 4.5 ft and--sft above mean sea level. Covered wittr- : rushes, barley grass and salt 'weeds it was carrying 200 ewes before the development project began. Already ewe numbers are up to 400 and; next year should go to 600. Iti is the opinion of Mr D. J. G. Davies, an instructor in agriculture with the Department of Agriculture, who knows] this area well, that fully de-; veloped this country should be capable of carrying at least five sheep to the acre and even more. The stopbank, completed in i March of last year, joins the old Halswell canal and is sft 9in high. 25ft wide at the base and about 6ft wide at the apex, and has a 3ft wide culI vert through it. The cost of i erecting the stopbank and in- ] stalling the culvert with flood ■ gate and slide gate was about £646. In addition on the banks of the Halswell canal Mr Woods has set up a pump house with an axial flow pump, powered by a 20 horsepower electric motor, capable of delivering 5000 gallons of water a minute. The purchase of the pump and its installation and the erection of the pumphouse and construction of a concrete lined channel to carry the water onto the land nas cost Mr Woods another £1720. Irrigation of the land with water pumped from the Halswell canal began this summer. Already the land has been i given two waterings at an in■terval of six weeks. It takes six days’ and seven nights’ pumping to cover the land with about six inches of water. This is then held on the land for three days before it returns to the lake through the | culvert in the stopbank and ;to the canal through another pipe. The cost of a watering

is about f!5 a time—this is for electric power Already Mr Woods believes that there has been a remarkable response Io the waterings in the appearance of clover. Mr Davies says that the effect is also noticeable in the 'rushes which are darker in colour and stronger. L.-The aim of the watering is to wash the salt out of the land and also to produce more feed. A test done on the soil indicated a deficiency in eop- | per. Mr Woods said, and about •five weeks ago slb of blueIstone, 51b of super as a carjrier, a half bushel of short rotation ryegrass and about ■ lib of white clover was flown ion to the acre. Ploughing ; Mr Woods has begun to! i plough some of the country I with the, idea of putting it through greenfeed or turnips before sowing to a permanent grass and clover sward with some lucerne. He hopes soon to begin subdivision of the block and inside about five years or earlier he hopes to Shave all of the block sown to pasture and subdivided. The borrow pit, from which the spoil for the stopbank was scooped, forms a drain on the inside of the stopbank. and also, incidentally, a fence, but Mr Woods does not believe that deep drains inside the stopbank, which might be pumped out in the winter, will be necessary to enable stock to graze on this country at this time of the year. An interesting side effect of the use of fresh water on this property has been that an increase in bird life has been noticed, presumably 7 as a result of better feed conditions. An approach was made to i the North Canterbury Catchment Board for a subsidy for i this project, but Mr Woods . said that it had been turned i down because it was considl ered that it was of benefit ■ only to himself, and to a ; small degree to bis brother.

I A pioneer in this sort of i I development is Mr H. R. l iWoods. a brother of Mr L. W.j •J. Woods, whose property is t i next door. Here stopbanking, I began about 15 or 16 years I ago and when it was found; that the banks were not high enough they were raised. Mr Woods tried his hand at developing about 130 acres when elsewhere on his property he found that well water gave a good response and he wondered whether he might not get the same result on the country nearer the lake. He I installed an electric powered; pump with a capacity of 25001 gallons a minute, to help ! wash out the salt. This coun-' try has had superphosphate I about four or five times so that it has now had a total of about lOcwt to the acre, and as well clover and perennial ryegrass have been applied. There is now plenty of Palestine strawberry clover in the country and carrying capacity over the years has been raised about three times. Now Mr Woods is starting to plough with the idea of levelling the country and also sowing back to grass i and clover. He may use iabout scwt of super to the I acre and possibly even more

! in this process and is inter- I ' ested in testing to see what 11 rate of fertiliser is needed < ; to give maximum benefit. I i Mr Woods says that they have had no trouble getting , I grass and clovers established | and there has been no bloat < in cattle. He has kept a close eye on the Department . of Agriculture’s Greenpark j trials over the years. Mr Woods says that he | could bank on nine months , ' of effective grazing on this , country each year and even , , more where the lake level was | ' I low over the winter, but if the , i lake was unduly high there j J would be a drainage problem. | J . Loiigbank ji J 1 j One of the most impressive , projects currently under way is that of Mr A. H. C. Nutt. , Before the winter he hopes . to have 120 chains of stop- ( ' banking completed out of j some 204 chains of stopbank- j ■ ing needed to ring bank a , . block of 270 acres. The bank , is on the 3.7 ft contour, which . J is the level above mean j sea level at which the . Catchment Board opens the . ( lake in the winter. Building .

I of the bank began in January and shortly it is likely that two draglines will be used to speed up the work before the ground becomes too wet. Most of Mr Nutt’s 1130 acres property is subject to Hooding from the lake. He has demonstrated the posI sibilities of the country. Just with fresh water from wells carried in alkathene pipes and in shallow surface channels I strawberry clover and rye- : grasses have grown profusely, I even in the absence of super--1 phosphate and introduced (seed, but with the threat of flooding there is no guarantee that this feed will be available 'to stock at any particular i time and this is seriously impeding the farming of this I country and further development. The Bank Mr Nutt is building 66 chains of bank facing the lake. 30 more chains in a northerly direction and then 108 chains of bank around the arm of the Halswell river. The bank being built facing the lake is 45ft wide at the base and 14ft wide at the top and is 7ft high on average. : but at some points depending on the lie of the land it 'is higher still. Material from the surface is being used on the either side of the bank to facilitate growth of grasses and lucerne sown on the bank to help stabilise it. Calm lake conditions this winter are hoped for so that the new bank will have an opportunity to settle down without being unduly tested. A 14ft boom or terrace separates the bank from the borI row pit which will act as a I drain on the inside of the

bank—the boom is provided to prevent erosion in the event of a north easterly driving water in behind the bank. Mr Nutt hopes that the remaining 80 chains of the bank will be completed next summer.

Eventually it is hoped to also install a large axial flow pump here for both irrigation to leach the salt and grow feed and also to reduce the water level in the winter if the lake level is too high for the water to escape through the culyert. A 24 inch diameter culvert sits on a 45ft long slab in the bank to allow water to escape from the area. It has flood gates to keep lake water out and where necessary to hold irrigation water in. This country’ is also in rushes, salt weed and barley grass and as a result of desalting and establishment of improved pastures it is hoped to raise carrying capacity in the long term from about nil to five sheep and more to the acres, according to Department of Agriculture estimates. And this is not all the development projected in the area. It is only the first phase of the programme on Mr Nutt’s farm. Including other proposals of individual farmers and a proposed drainage scheme in the area. Mr Davies said this week that improvement was in sight on some 6000 acres, or about onethird of the country in this area that could be improved and developed by flood protection, desalting and drainage.