About the Project

Geographic Setting

The proposed Chakachamna Hydroelectric Project is bordered by the Alaska Mountain Range on the west and Upper Cook Inlet on the east. Chakachamna Lake and its tributaries, the Nagishlamina River, the Chilligan River, and Kenibuna Lake are located in the higher elevations of the study area above the Chakachatna River.  Kenibuna Lake, in turn, is supplied by the Neacola River, Another River, and the Igitna River.  At the mouths of major tributaries are large deltas, composed mainly of sand and glacial-fluvial deposits. These high elevation lands and waters support a variety of fish and wildlife. Chakachamna Lake is approximately 350 feet deep with mountains rising 3,000 to 4,000 feet above its steep, rocky shoreline.

Throughout the lower elevations of the Project area, absence of relief has contributed to the formation of an array or marshes, bogs, and ponds. Two major rivers transport the water from the mountains to the Cook inlet, collect runoff from the adjacent marshes and bogs, and provide both migration and spawning habitat for numerous species of resident and anadromous fish.

The McArthur River originates at McArthur Glacier but receives the majority of its water from Blockade Glacier.

The Chakachatna River originates at the outlet of Chakachamna Lake. The river flows 15 miles east through a canyon containing almost continuous rapids. In the low flatlands, the Chakachatna floodplain gets substantially larger until a portion of it is diverted to the Noaukta Slough. Past the divergence, it becomes much narrower.

The Noaukta Slough carries a large proportion of the Chakachatna's flow as it fans out into a two mile wide tangle of interlaced channels.  The Noaukta Slough then joins the McArthur River. Downstream from this confluence, the McArthur flows several miles to the Chakachatna River confluence, after which it passes through additional marches and tidal flats before reaching Trading Bay.