The Stony Creek watershed consists of 777 square miles (2,010 km²) mostly in the Coast Range foothills and a smaller area of the Sacramento Valley.
The area experiences a Mediterranean climate, with cool, wet winters and hot, dry summers.
The annual precipitation, 90 percent of which falls between November and April, ranges from 32 inches (810 mm) on the valley floor to 60 inches (1,500 mm) in the headwaters.
The watershed above Black Butte Dam drains about 740 square miles (1,900 km²), or 95 percent of the whole.
Grindstone Creek drains the largest area of any tributary, at 160 square miles (410 km²), followed by Little Stony Creek at 102 square miles (260 km²).

Black Butte Dam is considered the boundary between the upper and lower Stony Creek watersheds.
Above Black Butte Dam, most of the watershed is publicly owned in the Mendocino National Forest and various BLM and state lands, while about 96 percent of the lower watershed is privately owned.
Lower Stony Creek has formed an extensive alluvial fan in the Sacramento Valley which slopes downhill to the east.
The alluvial fan extends about 26 miles (42 km) north to south and 14 miles (23 km) east to west, and is made up mostly of fertile, well-drained soils.
Beneath the surface is the Stony Creek aquifer, whose primary source of recharge is Stony Creek.
The aquifer has an estimated volume of 3 million acre feet (3.7 km³) and is an important water source for agriculture.

Water quality in upper Stony Creek is impacted by naturally occurring sources of mercury and drainage from abandoned mines, and lower Stony Creek is affected by pesticide runoff and high temperatures.
Black Butte Lake has also suffered water quality issues, with a toxic blue-green algae bloom occurring most recently in summer 2017.
The watershed in between Stony Gorge and Black Butte Dams is highly impacted by erosion, both due to overgrazing by sheep and cattle, and due to the naturally erosive geology of the area.

Agriculture makes up most of the local economy, with the major crops being almonds, olives, oranges, wheat, and corn, and also dairy operations and pasture.
The upper watershed historically had a significant logging industry, although the amount of timber harvested saw a dramatic decline in the 1990s and has remained low since then.
The Stony Creek watershed consists of 777 square miles (2,010 km²) mostly in the Coast Range foothills and a smaller area of the Sacramento Valley. The area experiences a Mediterranean climate, with cool, wet winters and hot, dry summers. The annual precipitation, 90 percent of which falls between November and April, ranges from 32 inches (810 mm) on the valley floor to 60 inches (1,500 mm) in the headwaters. The watershed above Black Butte Dam drains about 740 square miles (1,900 km²), or 95 percent of the whole. Grindstone Creek drains the largest area of any tributary, at 160 square miles (410 km²), followed by Little Stony Creek at 102 square miles (260 km²).
Black Butte Dam is considered the boundary between the upper and lower Stony Creek watersheds. Above Black Butte Dam, most of the watershed is publicly owned in the Mendocino National Forest and various BLM and state lands, while about 96 percent of the lower watershed is privately owned. Lower Stony Creek has formed an extensive alluvial fan in the Sacramento Valley which slopes downhill to the east. The alluvial fan extends about 26 miles (42 km) north to south and 14 miles (23 km) east to west, and is made up mostly of fertile, well-drained soils. Beneath the surface is the Stony Creek aquifer, whose primary source of recharge is Stony Creek. The aquifer has an estimated volume of 3 million acre feet (3.7 km³) and is an important water source for agriculture. 
Water quality in upper Stony Creek is impacted by naturally occurring sources of mercury and drainage from abandoned mines, and lower Stony Creek is affected by pesticide runoff and high temperatures. Black Butte Lake has also suffered water quality issues, with a toxic blue-green algae bloom occurring most recently in summer 2017. The watershed in between Stony Gorge and Black Butte Dams is highly impacted by erosion, both due to overgrazing by sheep and cattle, and due to the naturally erosive geology of the area.
Agriculture makes up most of the local economy, with the major crops being almonds, olives, oranges, wheat, and corn, and also dairy operations and pasture. The upper watershed historically had a significant logging industry, although the amount of timber harvested saw a dramatic decline in the 1990s and has remained low since then.
Stony Creek (Sacramento River tributary)