Yolo Bypass
Yolo Bypass | |
---|---|
Coordinates | 38°33′N 121°36′W / 38.55°N 121.60°W |
Country | United States |
State(s) | California |
Characteristics | |
Area | 59,000 acres (24,000 ha) |
Hydrology | |
River(s) | Sacramento, San Joaquin, American |
The Yolo Bypass is one of the two flood bypasses in California's Sacramento Valley located in Yolo and Solano Counties.[1] Through a system of weirs, the bypass diverts floodwaters from the Sacramento River away from the state's capital city of Sacramento and other nearby riverside communities.[2]
During wet years, the bypass can be full of water. The main input to the bypass is through the passive Fremont Weir, where water spills from the Sacramento into the bypass if it reaches the 33.5 feet (10.2 m) crest. Downstream, the Sacramento Weir, just north of the city of
The bypass is crossed by the Yolo Causeway, a long highway bridge on Interstate 80, linking West Sacramento and the city of Davis, as well as by a rail causeway just north of the Yolo Causeway used by freight and Amtrak trains. To the north, Interstate 5 also crosses the bypass on the Elkhorn Causeway, east of the city of Woodland.
History
Sacramento experienced several severe floods prior to construction of the bypass. The Yolo Basin, a depression formed during the last ice age,[3]: 3.4-1 would fill up with water during the winter months from seasonal rainfall and runoff into the three rivers surrounding what is now the city of Sacramento (Sacramento, San Joaquin, and American). This created a diverse marsh ecosystem that could last more than 100 days. During the 1800s, seasonal flooding would limit travel and access between cities in the Sacramento River valley.
Destructive floods in 1862 and 1878 prompted various flood control measures, including the 11.5-mile (18.5 km) long Tule Canal (completed in 1864) along the eastern edge of the present-day Yolo Bypass; and the Elkhorn Weir (1897–1917), downstream of the confluence of the Feather and Sacramento Rivers.[4]: 3.6-4
Congress approved the Sacramento River Flood Control Project in 1911, with a plan to divert the water through multiple weirs and bypasses. The Yolo Bypass is one of two major bypasses in the
The Yolo Bypass extends approximately 41 miles (66 km) long, north to south, and 3 miles (4.8 km) wide. The western and eastern edges are defined by levees separated by a distance ranging from 7,000 to 16,000 feet (2,100 to 4,900 m) apart, except for an 8-mile (13 km) long segment immediately south of the mouth of Putah Creek.[7] The two largest sources for the Yolo Bypass are the Sacramento Weir, completed in 1916, and the Fremont Weir, completed in 1929.[3]: 3.4-4 [4]: 3.6-5
Uses
Almost 75% of the Yolo Bypass is privately owned, while the rest belongs to the Yolo Bypass Wildlife Area. Most of the land is used for agriculture during the summer and spring, and the rest makes up marshland. This marshland is ideal for animal habitat, and is also utilized for fishing, hunting, and other recreational activities.[8]
Flood control
Flood control is the main purpose of the Yolo Bypass. When the flowrate of the Sacramento River exceeds approximately 55,000 cubic feet per second (93,000 m3/min), the excess is released into the Yolo Bypass at the passive Fremont Weir,[9]: 548 near that river's confluence with the Feather River. The Fremont Weir, which lies along the south bank of the Sacramento, is about 32 feet (9.8 m) tall, nearly 12 feet (3.7 m) shorter than the levee on the north bank. When the water reaches the 32 feet (9.8 m) mark it starts to flow out into the Yolo Basin.[10]
North of where the Elkhorn Causeway crosses the Yolo Bypass, the Cache Creek flood control basin drains into the Yolo Bypass.[6] The Knights Landing Ridge Cut, where the Colusa Basin Drainage Canal empties, also contributes to the flow in the Yolo Bypass near this point.[9]: 587
There is a second weir just north of West Sacramento, the Sacramento Weir, upstream of the confluence of the Sacramento and American Rivers. The Sacramento Weir is opened manually when the Sacramento River reaches 27.5 feet (8.4 m) at the I Street Bridge. It was built in 1916 by the City of Sacramento and contains 48 gates over its 1,920-foot (590 m) length; water from the Sacramento Weir flows through the 1 mile (1.6 km) long Sacramento Bypass and drains into the Yolo Bypass.[6] The crest of the Sacramento Weir is at 25 feet (7.6 m) and the top of the moveable gates is 31 feet (9.4 m); each gate is 38.1 feet (11.6 m) long.[9]: 549
Name | Location | Capacity | Notes |
---|---|---|---|
Moulton Weir | 8 miles (13 km) N of Colusa 100 miles (160 km) N of Sacramento |
25,000 cu ft/s 42,000 m3/min |
Releases from Sacramento River to Butte Basin |
Colusa Weir & Bypass | 1 mile (1.6 km) N of Colusa 100 miles (160 km) N of Sacramento |
70,000 cu ft/s 120,000 m3/min |
Releases from Sacramento River to Butte Basin |
Tisdale Weir & Bypass | 10 miles (16 km) SE of Meridian 56 miles (90 km) N of Sacramento |
38,000 cu ft/s 65,000 m3/min |
Releases from Sacramento River to Sutter Bypass |
Fremont Weir | 8 miles (13 km) NE of Woodland 15 miles (24 km) NW of Sacramento |
343,000 cu ft/s 583,000 m3/min |
Releases from Sacramento River |
Sacramento Weir & Bypass | Tower Bridge
|
112,000 cu ft/s 190,000 m3/min |
Only manual weir in the Yolo Bypass system |
Cache Creek Settling Basin & Weir | 2 miles (3.2 km) E of Woodland | 30,000 cu ft/s 51,000 m3/min |
Covers 3,600 acres (1,500 ha) |
Water flowing through the Yolo Bypass is drained through a riparian channel along its southeastern edge, named the Toe Drain. In the Liberty Farms area, the bypass joins first Prospect Slough and then Cache Slough adjacent to the connection of the
The Yolo Bypass can hold approximately four times the flow of the Sacramento River. Together, the Sacramento River and Yolo Bypass are designed to handle a maximum flow of 600,000 cubic feet per second (1,000,000 m3/min), of which the Sacramento handles 110,000 cu ft/s (190,000 m3/min) and the bypass 500,000 cu ft/s (850,000 m3/min). This flood management relieves pressure on the surrounding river levee systems and reduces the risk of urban flooding in nearby cities, such as Sacramento or Davis. During wet years, which occur during more than half of all rainy seasons, the Yolo Bypass is flooded; when flooded, it covers an area equal to 1⁄3 the area of San Francisco and San Pablo Bays, to a depth ranging from 6 to 10 feet (1.8 to 3.0 m).[6]
The state of California has the right to inundate any land in the Yolo Bypass with
Wildlife habitats
The Yolo Bypass contains the Fremont Weir Wildlife Area, Sacramento Weir Wildlife Area and Yolo Bypass Wildlife Area. The Vic Fazio Yolo Wildlife Area is also part of the Yolo Bypass Wildlife Area and was the largest public/private restoration project west of the Florida Everglades. The entire bypass forms a valuable wetland habitat when flooded during the winter and spring rainy season. In the summer, areas of the bypass outside the wildlife areas are used for agriculture.
The Yolo Bypass provides habitat for over 280 terrestrial vertebrate species, changing throughout the seasons. The natural flooding provides an exceptionally good nursery habitat for native fish species, including the endangered
Habitat Management activities are monitored annually by the California Department of Fish and Wildlife's Wildlife Area Habitat Committee for area in the Yolo Bypass Wildlife Area. Each year they establish a specific management plan for different parts of the land. The targeted species for seasonal wetland management is the
Years with high flows in the Yolo Bypass also benefit fish populations in the San Francisco Estuary.[14][15] This is mainly because of increased habitat availability, food supply, larval transport, and reduced predation.
Agriculture
The floodplains of the Yolo Bypass are a surprisingly good farming ground for multiple seasonal crops. The California Department of Fish and Wildlife leases land to farmers through the Dixon Resource Conservation District. The most widely-grown crops include rice,
Agricultural crops in
Recreation and education
The Yolo Bypass provides a multitude of recreational uses and educational as well. The Yolo Bypass Wildlife Headquarters provides summer educational programs for children in kindergarten through high school. These programs include hands on activities on plants, animals, and wetlands, using the Yolo Bypass Wildlife Area as a classroom. They have summer camps, classes, and are open to schools wanting to coordinate field trips as well. The Bypass is also open for guided tours for all ages of the public every month.
The Yolo Bypass is often used for bird watching, hunting, and hiking. Game species include waterfowl (when the bypass is flooded), ring-necked pheasant, and mourning dove. There are also assorted trails that loop around the wetlands in the Yolo Bypass that may be accessed by the public.
Future
Recent modeling shows that increasing flow to the Yolo Bypass may be beneficial for animal habitat. An upcoming project looks to extend the Yolo Bypass by potentially pushing back the levees, and allowing more room for water to be released into the Yolo Bypass. Separately, the
The Nigiri Project
The Nigiri Project[16] is a collaborative research study being done in the Yolo Bypass at Knaggs Ranch by the UC Davis Center for Watershed Sciences, the California Department of Water Resources, and the nonprofit organization California Trout.
This research is being conducted to determine how
This project is currently funded by the
References
- ^ "A Framework for the Future: Yolo Bypass Management Strategy" (PDF). Yolo Bypass Working Group, Yolo Basin Foundation, and Jones & Stokes. August 2001. Retrieved June 28, 2018.
- ^ Tokita, Joyce; Cameron-Harley, Jamie. "Beneath the Flood". California Department of Water Resources. Retrieved 2009-02-28.
- ^ a b EDAW, Inc. (June 2008). "3.4 Geomorphology, Hydrology, and Water Quality". Yolo Bypass Wildlife Area Land Management Plan (Report). California Department of Fish and Game. Retrieved 5 December 2019.
- ^ a b EDAW, Inc. (June 2008). "3.6 Cultural Resources". Yolo Bypass Wildlife Area Land Management Plan (Report). California Department of Fish and Game. Retrieved 5 December 2019.
- ^ "Managing for Multiple Benefits: Farming, Flood Protection, and Habitat Restoration in the Yolo Bypass Wildlife Area" (PDF). February 21, 2013. Retrieved June 28, 2018.
- ^ a b c d e "Yolo Bypass And Its Sources" (PDF). California Department of Water Resources. Retrieved 5 December 2019.
- ^ "1.5.3 Surface Water Resources". Integrated Regional Water Management Plan, IA7: Yolo Bypass Integrated Project (PDF) (Report). Water Resources Association of Yolo County. April 2007. Retrieved 5 December 2019.
- ^ Cloé Garnache and Richard E. Howitt. "Species Conservation on a Working Landscape: The Joint Production of Wildlife and Crops in the Yolo Bypass Floodplain" (PDF). University of California, Davis. Retrieved June 28, 2018.
- ^ a b c Hendricks, Ernest LeRoy (1964). Compilation of Records of Surface Waters of the United States, October 1950 to September 1960, Part 11. Pacific Slope Basins in California; Geological Survey water-supply paper 1735. Washington, D.C.: United States Department of the Interior, Geological Survey / United States Government Printing Office. pp. 548–549, 587. Retrieved 6 December 2019.
- ^ "Our third river". Sacramento News & Review.
- ^ "FLloodplains: Lessons from the Cosumes River and Yolo Bypass". Delta Council. Retrieved June 28, 2018.
- ^ "Building Rivers: The Yolo Bypass - Hiding in Plain Sight". NRDC. September 23, 2011. Retrieved June 28, 2018.
- ^ Biological Resources Retrieved June 28, 2018.
- .
- .
- ^ The Nigiri Project Retrieved June 28, 2018.
- ^ "Nigiri Project Mixes Salmon and Rice Fields for Fifth Year on Floodplain". ucdavis.edu. University of California, Davis. February 23, 2016. Retrieved June 28, 2018.
Further reading
- Christian-Smith, Juliet. Managing for Multiple Benefits: Farming, Flood Protection, and Habitat Restoration in the Yolo Bypass Wildlife Area (PDF) (Report). Pacific Institute. Retrieved 23 April 2016.
- "About the Yolo Bypass Wildlife Area". Yolo Basin Foundation. Retrieved 23 April 2016.
- "Environmental Services". Division of Environmental Services, California Department of Water Resources. Retrieved 23 April 2016.
- Garnache, Cloe; Howitt, Richard E. (July 24–26, 2011). Species Conservation on a Working Landscape: The Joint Production of Wildlife and Crops in the Yolo Bypass Floodplain. 2011 Annual Meeting. Agricultural and Applied Economics Association. .
- Kiparsky, Michael (October 2003). "Floodplains: Lessons from the Cosumnes River and Yolo Bypass" (PDF). California Bay-Delta Authority. Retrieved 23 April 2016.