Putah Creek is a major stream in Northern California, a tributary of the Yolo Bypass, and ultimately, the Sacramento River. The 85-mile-long (137 km) creek has its headwaters in the Mayacamas Mountains, a part of the Coast Range, and flows east through two dams. First, Monticello Dam forms Lake Berryessa, below which Putah Creek forms the border of Yolo and Solano Counties, and then flows to the Putah Diversion Dam and Lake Solano. After several drought years in the late 1980s, the majority of Putah Creek went dry, prompting a landmark lawsuit that resulted in the signing of the Putah Creek Accord in 2000. The Accord established releases from the dams to maintain stream flows in Putah Creek, with natural flow regimes which spike in winter/spring and ebb in summer/fall. The restoration of natural flow regimes has resulted in a doubling of riparian bird species and a return of spawning native steelhead trout and Chinook salmon, as well as protecting the livelihood of farmers on the lower watershed.

The Sacramento River is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for 400 miles (640 km) before reaching the Sacramento–San Joaquin River Delta and San Francisco Bay. The river drains about 26,500 square miles (69,000 km2) in 19 California counties, mostly within the fertile agricultural region bounded by the Coast Ranges and Sierra Nevada known as the Sacramento Valley, but also extending as far as the volcanic plateaus of Northeastern California. Historically, its watershed has reached as far north as south-central Oregon where the now, primarily, endorheic (closed) Goose Lake rarely experiences southerly outflow into the Pit River, the most northerly tributary of the Sacramento.