The watershed drains more than 940 sq miles, or 600,700 acres. More than half of its length it runs through forested areas over rugged terrain. The lower reaches flow through agricultural and densely populated areas. The watershed crosses two counties and includes federal land administered by the US Forest Service and BLM, state land, and private land.
Unlike the Bull Run Watershed, which is federally owned and managed by the City of Portland, 72% of the of the Clackamas watershed is publicly owned, 3% is tribally owned, and 25% is privately owned. The watershed can roughly be divided in half, with nearly all of the upper watershed in the Mt. Hood National Forest and managed by the USFS. In contrast, most of the lower watershed is privately owned. The area in between the national forest and the lower watershed include parcels of land owned by private timber companies and the BLM. The estimated population within the watershed in 1995 was 63,702.
The Clackamas River supplies high-quality drinking water for nearly 300,000 people in Clackamas and Washington Counties and is targeted in the Regional Water Supply Plan as a source to meet future demand.
There are five municipal surface water intakes on Clackamas. They include: