Cache Creek (Sacramento River)
|Rivière la Cache|
Cache Creek, Lake County section, California
|Regions||Yolo County, Colusa County, Lake County|
|- location||southwest of Clearlake, California|
|Mouth||Cache Creek Settling Basin|
|- location||east of Woodland, California|
|- elevation||30 ft (9 m) |
|Length||87 mi (140 km)|
|Basin||1,139 sq mi (2,950 km2)|
|Discharge||for Yolo, CA|
|- average||533 cu ft/s (15 m3/s)|
|- max||41,400 cu ft/s (1,172 m3/s)|
|- min||0 cu ft/s (0 m3/s)|
Cache Creek is an 87-mile-long (140 km) stream in Lake, Colusa and Yolo counties, California. Cache Creek starts at the outlet of Clear Lake. It has two main tributaries: North Fork (starting in the Mendocino National Forest north of Clear Lake, and dammed by the Indian Valley Reservoir); and Bear Creek (starting in Bear Valley).
The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a network of canals. At the end of the Capay Valley, near Esparto, Cache Creek runs east into Central Valley, ending in a settling pond east of Woodland, the overflow of which runs into the Sacramento River through a flood control canal.
In addition to the recreational use of Clear Lake and Indian Valley Reservoir there are numerous trail-heads, parks and campgrounds, including the Bear Valley wildflower hotspot. Bear Creek and Cache Creek run in a scenic canyon along State Route 16 in Colusa and Yolo county, including the Cache Creek Regional Park. Cache Creek provides white-water rafting, both in the spring when it is flooded, and through the summer using the agricultural water flow. The entire area south of Route 20 and west of Route 16 is a wildlife preserve, hosting two herds of Tule Elk.
The name of the water body comes from Hudson's Bay Company trappers who cached their furs along the Sacramento River and smaller tributaries, one of which became known to them as Cache Creek. One of their camps, recognized by early settlers as French Camp, was situated in a grove of oaks on the north bank of Cache Creek one mile (1.6 km) east of the present town of Yolo, California. Cache Creek was originally known to the Hudson's Bay Company trappers as Rivière la Cache.
Cache Creek has two main tributaries: North Fork, and Bear Creek.
Cache Creek begins at the south-east end of Clear Lake (for which it is the outlet), east to the dam which now controls the level of Clear Lake.
The North Fork begins in Lake County in the Mendocino National Forest north of Upper Lake. It flows east, where it is joined by Bartlett Creek, and is then dammed by the Indian Valley Reservoir. It then flows south along New Long Valley Road, and turns east along State Route 20, which it crosses at the Cache Creek Recreation Area.
Cache Creek runs north-east from the dam, behind Perkins Creek Ridge, joining the North Fork about 2 miles east of the bridge over Route 20.
Bear Creek starts in Bear Valley and runs south through a canyon (joining Sulphur Creek near Wilbur Springs) until it meets Route 20. It then runs east in parallel with Route 20 for a few miles, and turns south, again cutting through a canyon following State Route 16 in Colusa and Yolo Counties.
Meanwhile Cache Creek cuts south-east between Cache Creek Ridge (on its north bank) and Little Blue Ridge (south bank), joining Bear Creek at Route 16 near the junction of Lake, Colusa and Yolo counties. The combined Cache Creek continues in the canyon until it emerges north of Rumsey in Capay Valley.
At the end of the Capay Valley near Esparto Cache Creek runs east into Central Valley, ending in a settling pond east of Woodland. If the Sacramento river is not in flood then any overflow runs into the Tule Canal,continues as Prospect Slough and finally enters the Sacramento River at Cache Slough. If the Sacramento IS in flood, then the overflow from the settling pond is swept into the Yolo Bypass and Sacramento Bypass flood control system, emerging directly at Cache Slough.
Water rights and flooding protection have been in dispute between Yolo and Lake Counties since the late 19th century.
The Yolo County Flood Control & Water Conservation District ("Yolo") has "an 1855 priority right to divert the natural flow of Cache Creek, and 1912 priority right to store waters in Clear Lake to elevation 7.56 feet Rumsey Gauge for later release and beneficial use." Various decrees attempt to ensure a balance between the needs of the two counties, although high-water conditions can cause temporary disagreements. Under the Solano Decree Yolo currently holds appropriative rights for up to 150,000 acre feet (190,000,000 m3) per year from Clear Lake, and all the water from the Indian Valley dam.
The Cache Creek Dam on the South Fork of Cache Creek, five miles (8 km) downstream from Clear Lake, was built to increase Clear Lake's capacity and to regulate outflow for downstream users of Cache Creek water. The dam was later modified to include a 3 MW hydroelectric plant. The stream has a relatively small capacity, less than a quarter of the amount the dam is able to release. There is a rock ledge a mile and a half downstream of Clear Lake, called the Grigsby Riffle, near the bridge on State Route 53. This ledge restricts the amount of water that can flow through at that point. The limited capacity of the stream means that it takes a very long time to drain excess flow from Clear Lake, increasing the chance of flooding around the lake. The bottleneck is seen as a backup to prevent flooding downstream and Yolo County is prohibited from increasing the capacity of the channel by the Gopcevic and Bemmerly Decrees.
The Indian Valley dam on the North Fork of Cache Creek forms Indian Valley Reservoir. The dam's primary purpose is water storage for irrigation, but a 3.3 MW hydroelectric plant was built to take advantage of the falling water.
The Capay Diversion Dam, west of Capay, diverts water for distribution throughout Yolo County using a 175 mile (280 km) network of canals. For example, water is pumped into the Winters Canal, which runs south and ends in a reservoir near Winters. This feeds into Willows Canal, which runs east for miles alongside Putah Creek -- the water of which is used primarily by Solano County. The 474 foot long, 15 foot high concrete dam was constructed in 1914. In 1994 its apron was raised with a 5-foot high inflatable bladder (the "longest in the world"), which can be raised or lowered in 30 minutes. It underwent substantial repairs starting in 2009. 
Wildlife and Recreation
A large part of the creek within Lake County is designated a Wildlife Area by the state of California and the federal Bureau of Land Management, on which vehicles are prohibited but hiking, primitive camping, and hunting are allowed. The North Fork and Bear Creek each host a growing population of the rare tule elk, plus winter populations of bald eagles. The ruggedness of the area tends to ensure its isolation from human activity. In 2006 the United States Congress designated 27,245 acres (110 km²) of the area as the federally protected Cache Creek Wilderness. Cache Creek Conservancy  has restored a 130 acre Cache Creek Nature Preserve area downstream in the watershed.
Nominally a tributary of the Sacramento River, Cache Creek now only reaches it during extremely wet years due to damming and diversion of the stream's water. Degradation of the channel caused by invasive plants, such as Arundo donax and Tamarix spp., as well as gravel mining has left no suitable habitat for Chinook salmon and steelhead to spawn, even if there is enough water. Consequently, there are no longer any anadromous fish species in Cache Creek.
State Wild and Scenic River
Cache Creek was added to California's Wild and Scenic Rivers System in October, 2005 which protects 31 miles (50 km) of the river from construction of new dams or diversions. Assembly member Lois Wolk introduced AB 1328 in 2005 which received support as well as opposition. New dam construction on Cache Creek was being considered in 2002 by the Yolo County Water District, the agency that had built the Indian Valley Dam and the present dam on Cache Creek.
- U.S. Geological Survey Geographic Names Information System: Cache Creek
- U.S. Geological Survey Geographic Names Information System: Cache Creek Settling Basin
- U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National Map, accessed March 10, 2011
- http://www.pa-roots.com/~yolo/maps/locations1.html#C pa-roots.com
- National Maps Viewer. "Cache Creek Hydrography". Map. USGS. Retrieved 22 February 2014.
- "WMP District Water Supply.". Article. Yolo County. Retrieved 10 February 2014.
- Jenkins, Mimi. "Conjunctive Use without management". Masters Thesis. UC Davis. Retrieved 15 February 2014.
- Moyle, Peter (4 March 2011). "Capay Diversion Dam is key to Yolo County’s water works". The Davis Enterprise. Retrieved 16 February 2014.
- Sabol, George. "Capay Diversion Dam Modernisation". Report. Yolo County Flood Control and Water Conservation District. Retrieved 16 February 2014.
- "Cache Creek Conservancy". Retrieved 3 February 2013.
- Tuthill, Bill. "Cache Creek in Capay Valley". Guide. California Creeks. Retrieved 22 February 2014.
- Tuthill, Bill. "Bear Creek into Cache Creek". Guide. California Creeks. Retrieved 22 February 2014.
- Logson, Terre (10-12-05). "Cache Creek Bill Signed". Sacramento River Portal and Library website. Lake County Record Bee. Retrieved 2009-04-08.
- "Cache Creek Bill Progresses Despite Opposition". Headwaters (Friends of the River) (Spring 2005): p. 14.
- Lake County Water Resources Division
- Yolo County Flood Control & Water Conservation District
- Cache Creek Bioregion Information from UC Davis
- Trust for Public Land (PDF)
- Cache Creek Natural Area BLM website