SEM Solutions were awarded the contract for water management on this site in January 2000 as part of a performance contract with the Department of Public Works in Johannesburg. The aim of the contract was to reduce water consumption and to monitor the consumption thereafter. After the preliminary investigation, our report for implementation would include leak detection, pressure control, pipe layout, upgrade of certain fittings, fitting water meters etc.

We started our investigation and implementation in Nov. 2002. First step was obtaining history consumption data from Nigel Council.

(see visuals in the article on the right)

The first water consumption profile recordings were done in Feb. 2003. This was obtained after several severe leaks on the mains were already closed. The site had two water supplies from the council. To assure proper control of consumption, the one supply was abandoned. It also has two sets of mains, the old steel pipes and the new cement pipes. One discovery was that the old steel pipes were not phased out.

(see visuals in the article below)

Eventually it was discovered that the portion of high flow was due to the golf course irrigation system being open through the night. The low flow portion was assumed to be the potential flow for the site under normal consumption conditions.

The results achieved for 2003 were good and the temptation was to leave it at that. But the problem of high consumption from the golf course would remain. It was calculated that the consumption would reduce from ±14 000 m³ per month to ±7 000 m³ per month if the golf course water consumption could be eliminated.

The first attempt to obtain borehole water at the military base was abandoned after 3 dry holes were drilled. However, at Dunnottar Military Base there were two boreholes that were unused. So the emphasis shifted towards these two holes. They were tested for flow and durability. The test was successful.

The planning for the lay of a 4 km pipe line to the reservoir at Marievale Military Base started. The most interesting part was the ditch switch machine, as can be seen on the photo in the article to the right.

Eventually the project was successful. It takes about an hour from when the pumps have been started for the water to emerge from the pipe line at the reservoir. The reservoir has a storing capacity of 500 m³. The water consumption reduced to ± 7 000 m³ per month, as can be seen for the consumption during 2004 and 2005. Part of the success is due to the cooperation of the staff at the golf course.

(see visuals in the article below)

Maintaining a zero-flow of 5 m³/hr takes some effort, but appears to be possible with the help of a GSM-logger that reflects the consumption profile in our offices on a daily basis.

Now that the consumption has been optimized, the seasonal pattern starts to show, as can be seen from the consumption history for 2004 and 2005. The consumption increases during the dry months after the winter before the rain starts. It is also the period where it is sometimes necessary to assist the golf course with water supply from the council mains.

At a cost of ±R6.00/m³, the annual cost of water reduced from R2 m to R550 000, ±27% of what it was.