Water, vital for farming, was an elusive commodity for the farmers in the Ashton and Montagu districts in the Klein Karoo and in 1981 the Cogmanskloof Irrigation Board's Water scheme was formed. The scheme now supplies irrigation water to 107 fruit farmers and without the scheme there is very little permanent water.

After a few years, the system has proved itself as a reliable source of water for the area and started expanding, and after initially been known as 'Black snake', its name has now been changed to 'Golden vein'. Since the last upgrade in 1994, the demand to supply more water to the irrigators has grown so much that it has now become a matter of urgency to extend the system.

In search of an economical solution to the greater demand, the board is using Aquanet supplied by Allyson Lawless to analyse the existing network and test alternative scenarios to arrive at a cost effective network. The entire network has been modelled on Aquanet, and field readings match very closely with the results determined from the analysis, including velocities, pressures and flow through the pumps. So confident are the designers of the software results, that they are using the software to determine and price alternative boosting regions for each of the municipalities.

The wide seasonal variation in water availability and demand dictated that Aquanet be extended to cope with a 52-week demand cycle, which is now an important selling point of the product. The various scenarios developed for the municipalities are presently being weighed up against building new pipelines and extending their own networks. A collaborative development effort among all the water users in the area will mean a more efficient system for all, and reduced anxiety during the dry season, as the 'Golden vein' will pump water to all who need it.

Allyson Lawless

(011) 476 4100