The Cobb Reservoir is a hydro storage lake fed by the Cobb River in the Tasman District of the South Island of New Zealand. The reservoir feeds the Cobb Power Station and is 819 metres above sea level but drops significantly with low rainfall. Cobb Reservoir is the highest hydro storage lake in New Zealand, and is entirely surrounded by Kahurangi Nation…The Cobb Reservoir is a hydro storage lake fed by the Cobb River in the Tasman District of the South Island of New Zealand. The reservoir feeds the Cobb Power Station and is 819 metres above sea level but drops significantly with low rainfall. Cobb Reservoir is the highest hydro storage lake in New Zealand, and is entirely surrounded by Kahurangi National Park. The reservoir, dam, penstock and powerhouse are excluded from the national park.