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IRRIGATION AND WATER-SUPPLY. Irrigation is considered one of the most important developmental works being carried out by the Government. In Otago there are now thirteen schemes in operation, commanding an area of 63,000 acres, of which 50,000 acres are regularly irrigated and last year the revenue received from the sales of water was £25,980, as against £24,100 the previous year. No new work was undertaken in Otago as the schemes investigated did not show sufficient promise to justify proceeding with them. This condition is due to the necessity for expansive conservation of water in dams or the high cost of pumping water to higher altitudes. In Canterbury there are two schemes in operation, commanding 17,403 acres, of which 2,491 acres were irrigated last season, and £334 revenue was obtained. The irrigating season both in Otago and Canterbury was noted for the unprecedently wet weather conditions that obtained until the middle of January, and the exceptionally dry conditions that then set in and persisted until the end of June. The effect, of this uncommon season was to delay the demand for water until the season was half oyer, thus leaving many of the irrigators unprepared for the drought that followed. This adversely affected the revenue on the schemes whiclTliupplied water on demand—namely, the Omakau Scheme in Otago and the Redcliff and Levels Schemes in Canterbury. The year's construction activity was confined to Canterbury on schemes which will derive their water-supply from the Rangitata River. It was found in Canterbury that the main rivers provided the most reliable source of water-supply on account of possessing large glaciers at their sources, which act as natural storage reservoirs which let the water down during hot north-westerly winds, when it is most required. For this reason schemes of considerable magnitude must be undertaken at one time. The area in the Ashburton County between the Rangitata and Rakaia Rivers proved the most promising one to start on, and this entailed the authorization of the large supply race known as the Rangitata Diversion Race. This race is 42 miles long, and, besides supplying 1,000 cusecs of water for the irrigation of 234,000 acres of land, it is also capable of generating 30,000 horse-power of electric energy during the winter months, when the water is not required for irrigating the land. The construction of this race is being vigorously proceeded with ; eighteen large mechanical plant units are being worked three shifts each day, moving 125,000 cubic yards of excavation per month, and to date about one-half of the 3,000,000 cubic yards of earthwork contained in the work is completed. Other features of the main race construction comprise a large concrete headworks and regulator, a 12-ft.-diameter reinforced-concrete syphon 8,700 ft. long, and six 11-ft.-diameter reinforced-concrete syphons to carry the race under the Ashburton and Hinds Rivers and their tributaries. The turbine and generating set for the electric-power development have been ordered, and the race and power development is scheduled to be completed by the winter of 1941. Concurrent with the construction of the Rangitata Race, two large irrigation schemes—namely, the Mayfield-Hinds scheme 54,000 acres, and the AshburtonLyndhurst scheme 34,000 acres —are proceeding, and are scheduled to be ready when the main race is completed. These schemes also entail the removal of large

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