Wednesday, April 1, 2015
YOLO COUNTY NEWS
99 CENTS

Bypass floodwaters close wildlife area

Floodwaters make a pattern in the Yolo Bypass Wildlife Area on Thursday afternoon, after the Fremont Weir was overtopped on Monday. The bypass, about three miles wide and 40 miles long, handles overflow from the Sacramento River. Sue Cockrell/Enterprise photo

By
From page A1 | December 28, 2012 |

The Yolo Bypass is filling with water due to the recent heavy rains, and the Yolo Bypass Wildlife Area is in the midst of a seasonal closure as a result.

The California Department of Fish and Game announced Monday that the Wildlife Area was closing due to “forecasted flooding until further notice.”

And Ted Thomas, information officer with the California Department of Water Resources, confirmed Thursday morning that water is flowing over the Fremont Weir from the Sacramento River into the Yolo Bypass, and had been for the past day or so.

The Fremont Weir, completed in 1924, is a two-mile-long structure on the south side of the Sacramento River, not far from the confluence of the Sacramento and Feather rivers, at a point about eight miles northeast of Woodland and about 15 miles northwest of Sacramento.

When the river rises to 33.5 feet, water flows over the Fremont Weir and into the Yolo Bypass, which is roughly three miles wide and about 40 miles long. The Yolo Bypass conveys the water southward into the Sacramento-San Joaquin Delta, and the water ultimately flows into the San Francisco Bay.

The California Department of Water Resources describes the Yolo Bypass as “a great ‘safety valve’ taking huge quantities of water out of the river channel and allowing it to flow slowly and safely out to the delta.” Otherwise, there would be a high risk of flooding in the lower parts of the Sacramento urban area, a common event in the late 1800s.

When flooded, the Yolo Bypass also provides a stopover point for migrating wildfowl, and an excellent environment for fish that swim up through the delta to lay their eggs. Recent studies have shown that the slower-moving, nutrient-rich water in the seasonally flooded Yolo Bypass helps young fish grow more quickly than they would in the faster-moving, channelized Sacramento River itself.

At full flood, the Yolo Bypass also conveys an enormous amount of water — more than the river itself.

“The levee and bypass system along the Sacramento River system handle many times the normal flow of the Sacramento River,” according to the Department of Water Resources. When filled to capacity, the bypass system “carries a maximum of 600,000 cubic feet per second (cfs), many times the normal flow of the Sacramento River. Only a sixth of that flow — 110,000 cfs — is carried by the river itself. Nearly 500,000 cfs is channeled into the Yolo Bypass.”

This includes water that flows over Fremont Weir, as well as water entering the Yolo Bypass from creeks and sloughs along the side of the bypass.

The seasonal flooding of the Yolo Bypass in wet winters creates a large and comparatively shallow body of water.

“In more than half of all water years (from Oct. 1 to Sept. 30), the Yolo Bypass is inundated,” according to the Department of Water Resources. “When completely flooded, the Yolo Bypass covers an area equal to about one-third the size of San Francisco and San Pablo Bays. Water depths range from 10 feet in a heavy year to around 6 feet in a normal year.”

Seasonal flooding in the Yolo Bypass can inundate the acreage for anywhere from a few days to a few months, depending on how hard it rains and snows over the watersheds of the Sacramento River, the Feather River and their tributaries, officials said.

The Yolo Bypass includes about 59,000 acres of land, of which roughly 17,700 acres is part of the Yolo Bypass Wildlife Area. The remainder of the land includes private duck clubs and agricultural land, including a substantial amount of acreage devoted to rice.

— Reach Jeff Hudson at [email protected] or 530-747-8055.

Comments

comments

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

     
    Food Bank springs for year-round assistance

    By Anne Ternus-Bellamy | From Page: A1 | Gallery

     
    Next-generation GMOs: Pink pineapples and purple tomatoes

    By The Associated Press | From Page: A2 | Gallery

     
    Dismal snowpack gets one more measure

    By The Associated Press | From Page: A2

     
    Funding sought for slain vet student’s pets

    By Lauren Keene | From Page: A2

    Woodland Library’s community room reopens

    By Enterprise staff | From Page: A3

     
    Museum celebrates Easter with candy-filled eggs

    By Enterprise staff | From Page: A3

    Easter egg hunt set Sunday at Atria

    By Enterprise staff | From Page: A3

     
    AquaMonsters open summer registration

    By Special to The Enterprise | From Page: A3

     
    Odd Fellows will host a big birthday bash

    By Special to The Enterprise | From Page: A6

    Tamblyn presents a comedy concert

    By Special to The Enterprise | From Page: A6 | Gallery

     
    Cancer fighters will gather Saturday for Relay For Life kickoff

    By Special to The Enterprise | From Page: A6

    Poet laureate emerita celebrates at book-release party

    By Special to The Enterprise | From Page: A6

     
    UCD gets grant to look at open access to published research

    By Special to The Enterprise | From Page: A6

    AARP’s free tax-prep services continue

    By Special to The Enterprise | From Page: A7

     
    Round up at the registers for Davis schools

    By Enterprise staff | From Page: A7

    ‘Sip and Shop’ kicks off Child Abuse Prevention Month

    By Special to The Enterprise | From Page: A7

     
    Pain management lecture slated April 8

    By Special to The Enterprise | From Page: A8

    Seniors invited to join new social group

    By Anne Ternus-Bellamy | From Page: A8

     
    Pence Gallery: See artists at work during Garden Tour

    By Natalie Nelson | From Page: A10 | Gallery

    .

    Forum

    Program sparks lots of questions

    By Letters to the Editor | From Page: B4

     
    Is Davis on the cusp of an evolutionary change?

    By Rich Rifkin | From Page: B4

    Will containers block cyclists’ path?

    By Letters to the Editor | From Page: B4

     
    We have no room for another cart

    By Letters to the Editor | From Page: B4

    This is no way to run a city

    By Letters to the Editor | From Page: B4

     
    Get informed on organics program

    By Letters to the Editor | From Page: B4

    Bicycle bells are my birthday wish

    By Letters to the Editor | From Page: B4

     
    Tom Meyer cartoon

    By Debbie Davis | From Page: B4

    Shootings showed need for MRAP

    By Letters to the Editor | From Page: B4

     
    Groom’s parents overwhelmed

    By Creators Syndicate | From Page: B5

    .

    Sports

    Aggies get ready for Hawaii by rolling over St. Mary’s

    By Bruce Gallaudet | From Page: B1 | Gallery

     
    UC Davis represents well at Final Four in Indiana

    By Bruce Gallaudet | From Page: B1 | Gallery

     
    Descalso looks back at Aggie days, ahead to new Rockies gig

    By Bruce Gallaudet | From Page: B1 | Gallery

    Blue Devils drop softball game at CBS

    By Enterprise staff | From Page: B1

     
    JV/frosh roundup: DHS younger girls soccer squad stomps Grant

    By Enterprise staff | From Page: B2 | Gallery

    UCD roundup: Nunez powers Aggies to softball win

    By Enterprise staff | From Page: B3 | Gallery

     
    Gibson’s heroics ensure a DHS split at Boras Classic

    By Enterprise staff | From Page: B10

    .

    Features

    Spring is a busy time for honey and hives

    By Dan Kennedy | From Page: A8 | Gallery

     
    .

    Arts

    Bluesman and guitarist Buddy Guy comes to Davis

    By Jeff Hudson | From Page: A9 | Gallery

     
    Fiery bluesman brings guitar pyrotechnics to The Palms

    By Special to The Enterprise | From Page: A9 | Gallery

     
     
    .

    Business

    .

    Obituaries

    .

    Comics