DWS ‘shrinks’ the Theewaterskloof Dam to get its last 10% of water

A reservoir that usually holds more than 50% of Cape Town’s surface water is now being drilled and shrunk for its last drop.

The Department of Water and Sanitation (DWS) this week began “emergency works” at the city’s largest dam, which will allow the remaining 10% of the water to be accessed.

That 10%, rather annoyingly due to the design of the dam, remains on the opposite side of the dam’s outlet pipe — the pipe through which water from the dam is funneled and pumped to the city.

But the DWS has a plan. Leonardo Manus, chief director for infrastructure operations and maintenance, explains that a cofferdam is current being constructed.

DWS Leonardo Manus explains the works at the Theewaterskloof dam pic.twitter.com/3cIqE2TMLx

— Water&SanitationRSA (@DWS_RSA) February 22, 2018

More details on the work done at the Theewaterskloof dam pic.twitter.com/Df3idtWe24

— Water&SanitationRSA (@DWS_RSA) February 22, 2018

Once complete, the cofferdam will temporarily make the Theewaterskloof Dam “a little bit smaller”, explained the Western Cape’s DWS regional head Rashid Khan, but will allow the department to gather and access the remaining water.

The Theewaterskloof Dam’s ‘cofferdam’ will temporarily shrink it, but will allow its remaining 10% of water to be used

“Yes, we have already got some work done in the Theewaterskloof, so we can access the water that is now lying below the outlet pipe,” he added.

Western Cape DWS Regional Head talks about the drilling that’s underway at the Theewaterskloof dam pic.twitter.com/UaooGPSIy4

— Water&SanitationRSA (@DWS_RSA) February 22, 2018

Currently the Theewaterskloof Dam holds just 11% of its possible storage capacity, but that still equates to more than 54 000 megalitres, close to the entire capacity of the Wemmershoek Dam when full.

The cofferdam is not yet complete, but once it is constructed, the DWS’s emergency engineering measures will ensure that Cape Town has an additional 108 days of water, if consumption remains around the 500-million litres per day mark.

DWS did not state when work on the cofferdam will be completed.

Feature image: City of Cape Town