New dam envisaged for Khan River

Brigitte Weidlich
The Canadian Osino Gold Exploration and Mining company, which is currently developing the Twin Hills gold mine project about 25 km northeast of Karibib, is considering building a dam in the Khan River. This should supply the future mine with up to forty percent of its water consumption.
A mining company already planned to build a dam in the Khan River in the 1990s. However, this plan was scrapped after strong criticism.
The dam being considered by Osino will have a dam wall almost five meters high and a storage volume of approximately 786 000 cubic metres. Of this, only 500 000 cubic meters will be removed twice a year.
The gold mine is only supposed to be in operation for thirteen years, then the gold veins and gold deposits are believed to be exhausted.
"Despite the success of water supply studies carried out so far in the Karibib marble aquifer, Osino is still exploring other sources, including the Khan River Dam option," SLR Consulting said.
The gold project is located in an area where water is very scarce.
"The dam can supply up to 30 to 40 percent of the total mine water needs."
SLR said an environmental feasibility study requested at the behest of Osino began last year and public hearings were held in early August.
A draft of the report is now available. The primary water source for the gold project will be boreholes pumping groundwater from the Karibib marble aquifer. They are expected to produce approximately 3 300 cubic meters (m³) per day or 1.1 million m³ per year.
"This supply strategy is based on sustainable returns, which have been tested during the trial phase of the program and will later be supplemented by mine drainage," says SLR Consulting.
Environmentalists are concerned that the dam could limit the flow of water to the Swakop River during rainy seasons.
At one of the hearings it was recommended that Osino - like the Navachab gold mine near Karibib - get water from the Swakoppoort Dam.
The preliminary report can be viewed at Interested and affected parties as well as the public can comment on the content and write to SLR by 20 February.
Information can also be obtained from the following address: [email protected].
Public hearings are also planned as follows: In Karibib on 6 February at 14:00 in the town hall; in Usakos on 6 February at 18:00; and on 7 February in Omaruru at 12:00 in the town hall.