The Cobb Dam sits in the Cobb Valley, which is in the Kahurangi National Park.  The dam was started as a private venture in 1937 and then taken over by the government in 1940.  The dam sits at 808m above sea level, making it the highest hydroelectric water storage lake in New Zealand.  The dam is 596 metres above the power station, which is also the highest vertical head between dam and power station in New Zealand.  There are two 4 km long penstocks that feed water from the dam to the power station1.  The power station is now run by Trust Power and generates 32 MW of electricity from little water flow2

Access to the dam area is from the Cobb Valley road, which heads up the valley from the bottom of the Takaka Hill road.   The Cobb Valley Road becomes the Cobb Dam Road, which is an unsealed road that follows the Takaka River upstream.   The road passes the cobb power station and then climbs on a winding road that passes through native forest.

The highest point on the road is around 1,000 metres above sea level and at that point there are good views down over the Cobb Dam.  The road winds back down to the dam, where it forks to either the dam end or to the Cobb River end.  Turning to the dam end the road soon crosses the dam and soon after comes to a carpark for the track up to Lake Sylvester.   The road to the Cobb River follows the South-East shore of the lake formed by the dam and takes 20 minutes before it ends at a DOC campsite or Trilobite hut which are close to one another.

We camped several nights on the DOC campsite beside the Cobb River, towards the end of March.  The weather was pleasant, but nevertheless at the 800 metre elevation it was cold at night and there was a relatively thick fog towards dawn that soaked all the tents.  It took the sun a few hours to burn off the fog and dry the camping equipment.  Trout fishing in the Cobb river and the dam is possible.  We tried but had no luck.  There had been a severe drought in the several months before we camped so both the river and dam were very low.

From the camp site there are walks upstream along the Cobb River or South up the surrounding hills towards the South-East mountains in the Kahurangi National Park.  I took a half-day return hike up to Lake Peel.  Views over the Cobb Dam and the Kahurangi National Park were wonderful from the ridge line.