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Kaituna River Development. —A reconnaissance has been made of the upper portion of the Kaituna Eiver to select possible dam sites and lines of development. An aerial survey of the area on which it is intended to base future investigations is now being carried out by the Aerial Mapping Branch of the Lands and Survey Department. Geoihermal Steam Development at Wairahei. —An intensive programme of prospecting for development of geothermal steam was commenced in January, 1950. Geophysical survey work by the New Zealand Geological Survey is under way in the Wairakei area, a camp for fifty men is under construction at Taupo Township, and survey work has commenced on a line of prospecting-drill holes. Three drilling-rigs have been made available for prospecting drilling, and a further rig is being sent to the site. Preparations are under way to fit the drills with blow-out preventer gear suitable for pressure steam. The installation of water-mains for the drills is in hand in the area selected for the prospecting holes. Braeburn Power Project.- —lnvestigations were commenced early in 1950, a camp being established at Lake Rotoroa for this purpose. Surveys of the lake outlet, the western shore of the lake near the outlet, and the Mangles River are in hand. A geophysical survey of the outlet has been made, and the area has been flown in preparation for an aerial survey. The construction of access roads to various sections of the project is in progress. Benmore Power Project. —Work on this project has continued on a reduced priority, some of the men having been transferred to the more urgent investigations for Waitaki Station extensions. A seismic survey has been carried out on the river terraces downstream from the dam site to determine the thickness of the gravels, and a contour survey has been carried out on the spur forming the left bank abutment of the dam. An automatic water-level recorder has been installed on the Ahuriri River. Stripping of the talus on the dam site was carried out during the year, together with some exploratory drilling and tunnelling. Some additions to the camp accommodation have been carried out and a telephone fine to the works has been provided. Waitaki Station Extensions. —The right bank of the Waitaki River has been investigated by exploratory shafts and a drive near the existing power-house. Geologists of the New Zealand Geological Survey have reported on the condition of the foundation rock, and an investigation report has been prepared, resulting in recommendations and the approval of the project by the Government. Some preliminary surveys have been made for the temporary construction village. Lake Hawea Control Project.-— Shafts have been excavated at the lake outlet and a tunnel has been driven into the hillside to examine the geological structure of the foundations for the proposed control works. Drill holes have been put down across Hawea Flat for the determination of water-levels. Samples-'of soil from deposits adjacent t;o the control site have been tested for suitability for earth-dam construction. Site investigations for this project are now complete. Lake Wanaka Control Project. —A full-scale electro-osmosis test has been carried out on the glacial silts at the lake outlet, with very successful results. The test showed that this method of treating the silts can greatly assist the dewatering of excavations during construction of proposed control works. Roxburgh Power Project. —An exploratory drive has been excavated in the right abutment of the dam to examine the thickness of the talus, and drilling has been carried out to determine the rock profiles of the river bottom at the dam site. An investigation shaft has also been excavated on the left bank of the river. High-speed diamond drills were tested on the schist rock. Te Anau - Manapouri Development. —An aerial survey of the Manapouri - Deep Cove project has been completed. An aerial survey of the Te Anau - George Sound project is in hand.

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