What kind of volume of water is needed to irrigate the proposed 42,000 hectares?
We are looking at storing around 27Mm3 of water for part of the year in Lake Sumner. Lake Sumner has a natural variation in lake level which could be controlled by use of a small weir at the outlet. We have engaged hydrology experts to understand the exact volumes of water flowing throughout the year, and the total water volume required to irrigate 40,000 hectares. Reports on our progress with these studies will be added to the website as they come in. Storage in Lake Sumner would be supplemented by a dam on the South Branch of the Hurunui River. How much water we need depends on several factors, including how much we are able to store in Lake Sumner, the river’s minimum flows and the minimum size of dam needed to meet demand.
