DOCSLIB.ORG

Delta Region Drinking Water Quality Management Plan

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Delta Region Drinking Water Quality Management Plan DELTA REGION DRINKING WATER QUALITY MANAGEMENT PLAN DRAFT FINAL June 2005 Funding for this project was made possible by a CALFED Grant through the Drinking Water Quality Program This document was funded by the CALFED Water Quality Program as an initial effort to create Regional “Equivalent Level of Public Health Protection” Plans and to assist in establishing a uniform framework in such planning. It is not intended to be a final document. California Bay-Delta Authority and CALFED WQP Implementing Agency staff have not had the opportunity to review and comment on this document, and any opinions or interpretations of the CALFED program expressed within the document are solely those of its authors. The CALFED WQP is committed to working with these and other parties to continue development and refinement of Regional Plans. EXECUTIVE SUMMARY In 2004, the CALFED Bay-Delta Program (CALFED) commissioned a pilot program for development of regional drinking water quality management plans (i) to identify the drinking water quality issues and needs of drinking water agencies in different regions of California and (ii) to develop solutions to address those needs. This Delta Region Drinking Water Quality Management Plan (DRDWQMP) was developed jointly by Contra Costa Water District (CCWD), the city of Stockton (COS), and Solano County Water Agency (SCWA). Figure ES-1 shows the Sacramento-San Joaquin Delta (Delta) region, with an outline representing Delta boundaries as defined in California Water Code Section 12220, along with the service areas of the three participating agencies. These three agencies represent the largest urban water users within the Delta region. The objectives of the DRDWQMP include understanding existing water quality conditions (and anticipated future water quality conditions absent proactive actions) at the urban intakes within the Delta, identifying challenges and issues confronting agencies diverting water from the Delta, and developing projects and programs at the local, regional, and statewide level to address these issues and to ensure that in-Delta agencies can meet their water quality goals in the future. Bromide and salinity concentrations in central and south Delta in the fall, which decreased from the mid-1940s to the 1970s, increased appreciably over the past two decades (see Figure ES-2). The fall is when Delta outflows are lowest and salinities are highest. Organic carbon concentrations in the interior Delta remain high and have not shown a significant degradation or improvement. Runoff from the Barker Slough watershed continues to result in high organic carbon and turbidity at SCWA’s in-Delta intake. The decline in Delta water quality has negatively impacted agencies that divert water from the Delta for drinking water purposes. Evidence points to the risk of additional Delta water quality degradation in the future. The majority of the adverse impacts on Delta water quality and the in-Delta diverters are the result of actions by others, outside the control of in-Delta diverters. Population increase, global warming, and the risk of more frequent levee failures will likely continue this degradation trend unless actions are taken. At the same time, the prospect of new operational constraints to protect fish and more stringent drinking water regulations in the future are additional major challenges facing in-Delta drinking water providers. A number of projects and programs are being developed, or are in place, to address Delta water quality degradation at the statewide level through CALFED, and through local and regional projects, such as those discussed in this DRDWQMP. Draft Final ES-1 June 2005 Delta Region Drinking Water Executive Summary Quality Management Plan Figure ES-1 Sacramento-San Joaquin Delta Boundary and Boundaries of Delta Region Drinking Water Quality Management Plan Participating Agencies June 2005 ES-2 Draft Final Delta Region Drinking Water Quality Management Plan Executive Summary 300 Dry Years Wet Years 250 Severe 1977 Drought Long-Term Average 200 150 100 Rock Slough Chlorides (mg/L) Very Wet El Nino Years 50 0 1944 1949 1954 1959 1964 1969 1974 1979 1984 1989 1994 1999 2004 Year Figure ES-2 Fall Chloride Concentration in Rock Slough, 1944 to 2004 Over the last two decades, wet year salinities have been higher in the fall than those experienced during the drier 1960s and 1970s. CALFED BAY-DELTA PROGRAM CALFED has prepared a long-term comprehensive plan that will restore ecological health and improve water quality and water supply for beneficial uses of the San Francisco Bay/Sacramento-San Joaquin Delta system. The August 2000 CALFED programmatic Record of Decision (ROD) identified 11 “action plans.” Some of the action plans will improve drinking water quality for users of Delta water; however, other actions (e.g., wetlands restoration projects and projects to increase exports from the Delta) have the potential to negatively impact Delta water quality. Draft Final ES-3 June 2005 Delta Region Drinking Water Executive Summary Quality Management Plan CALFED WATER QUALITY PROGRAM The specific target of the CALFED Water Quality Program (WQP) is to provide safe, reliable, and affordable drinking water in a cost-effective way by achieving either of the following: a) Average concentrations at Clifton Court Forebay and other central and south Delta drinking water intakes of 50 micrograms per liter (Pg/L) bromide and 3.0 milligrams per liter (mg/L) total organic carbon (TOC), or b) An equivalent level of public health protection (ELPH) using cost-effective combinations of alternative source waters, source control, and treatment technologies (August 28, 2000, CALFED ROD, page 65) The WQP is investing in projects and programs to continuously improve water quality for the more than 23 million Californians who rely on the Delta for their drinking water supply. “EQUIVALENT LEVEL OF PUBLIC HEALTH” (ELPH) MODEL In 2002, the CALFED Bay-Delta Advisory Committee, Drinking Water Subcommittee, developed a framework for drinking water quality management: the “Equivalent Level of Public Health Protection Decision Tree.”1 The ELPH model is a conceptual model of the multibarrier approach needed to fully ensure that the state’s drinking water and public health are protected, and is being used to guide implementation of the CALFED WQP. The ELPH model provides a conceptual representation of the relationships between various water management operations, reduction of contaminant discharges into the Delta and its tributaries, and changes in source water quality to the Delta. The ELPH model, applied at the local, regional, and statewide level, is an excellent tool for identifying potential water management operations to improve Delta water quality and for developing strategies for implementing those operations (including the appropriate role of local, state, and federal agencies). The ELPH model implicitly recognizes that water quality objectives in source waters and water quality regulations protecting consumers are dynamic, and are best met with flexible plans that consider the entire drinking water system from source to tap. The DRDWQMP uses an “in-Delta” version of the ELPH conceptual model to present water quality solutions for the Delta urban agencies (see Figure ES-3). 1 http://calwater.ca.gov/BDPAC/Subcommittees/DrinkingWaterQualitySubcommittee.shtml June 2005 ES-4 Draft Final Delta Region Drinking Water Quality Management Plan Executive Summary Figure ES-3 CALFED Equivalent Level of Public Health Model Adapted to Delta Region POTENTIAL PROJECTS AND PROGRAMS Strategies are currently being implemented or considered locally, regionally, and statewide that would address the challenges and issues presented by the impacts on Delta water quality. DRDWQMP participating agencies, CCWD, City of Stockton Municipal Utility District (COSMUD), and SCWA, have identified potential projects and programs to improve and protect Delta water supplies and to improve the drinking water quality delivered to their customers. Projects, programs, and operational changes currently under consideration that have the potential to improve Delta water quality and/or the quality of water diverted from the Delta for drinking water purposes are presented and discussed below within the construct of the ELPH model developed by CALFED (see Figure ES- 4). Draft Final ES-5 June 2005 Delta Region Drinking Water Executive Summary Quality Management Plan Figure ES-4 Potential Projects and Programs of Delta M&I Water Users in the Equivalent Level of Public Health Model Analysis of existing water quality conditions indicated that CCWD’s primary water quality issue is high bromide concentrations at its Delta intakes. Organic carbon concentrations are generally higher than the CALFED target of 3.0 mg/L, but are currently manageable. CCWD is developing several major projects and programs to protect its future water quality needs and to improve the drinking water quality delivered to its customers: x An “Alternative Intake Project” to evaluate other points of diversion from the Delta for the purpose of improving water quality (both for direct delivery and storage in Los Vaqueros Reservoir for later blending to improve delivered water quality). The new intake will, at times, have lower bromide concentrations than CCWD’s existing intakes, which will help CCWD meet anticipated future drinking water regulations. x Encasement of the Contra Costa Canal to improve source water quality delivered to the Bollman and Randall-Bold water treatment plants (WTPs). This
Load more

Recommended publications
  • Draft Upper San Joaquin River Basin Storage Investigation
    Draft Feasibility Report Upper San Joaquin River Basin Storage Investigation Prepared by: United States Department of the Interior Bureau of Reclamation Mid-Pacific Region U.S. Department of the Interior Bureau of Reclamation January 2014 Mission Statements The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian Tribes and our commitments to island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. Executive Summary The Upper San Joaquin River Basin Storage This Draft Feasibility Report documents the Investigation (Investigation) is a joint feasibility of alternative plans, including a range feasibility study by the U.S. Department of of operations and physical features, for the the Interior, Bureau of Reclamation potential Temperance Flat River Mile 274 (Reclamation), in cooperation with the Reservoir. California Department of Water Resources Key Findings to Date: (DWR). The purpose of the Investigation is • All alternative plans would provide benefits to determine the potential type and extent of for water supply reliability, enhancement of Federal, State of California (State), and the San Joaquin River ecosystem, and other resources. regional interest in a potential project to • All alternative plans are technically feasible, expand water storage capacity in the upper constructible, and can be operated and San Joaquin River watershed for improving maintained. water supply reliability and flexibility of the • Environmental analyses to date suggest that water management system for agricultural, all alternative plans would be urban, and environmental uses; and environmentally feasible.
    [Show full text]
  • Structured Decision Making for Delta Smelt Demo Project
    Structured Decision Making for Delta Smelt Demo Project Prepared for CSAMP/CAMT Project funded by State and Federal Water Contractors Prepared by Graham Long and Sally Rudd Compass Resource Management Ltd. 604.641.2875 Suite 210- 111 Water Street Vancouver, British Columbia Canada V6B 1A7 www.compassrm.com Date May 4, 2018 April 13th – reviewed by TWG and comments incorporated Table of Contents Table of Contents ............................................................................................................... i Executive Summary .......................................................................................................... iii Introduction ...................................................................................................................... 1 Approach .......................................................................................................................... 1 Problem Definition ........................................................................................................... 4 Objectives ......................................................................................................................... 5 Alternatives ...................................................................................................................... 9 Evaluation of Trade-offs ................................................................................................. 17 Discussion and Recommendations ................................................................................
    [Show full text]
  • A Century of Delta Salt Water Barriers
    A Century of Salt Water Barriers in the Delta By Tim Stroshane Policy Analyst Restore the Delta June 5, 2015 edition Since the late 19th century, California’s basic plan for water resource development has been to export water from the Sacramento River and the Delta to the San Joaquin Valley and southern California. Unfortunately, this basic plan ignores the reality that the Delta is the very definition of an estuary: it is where fresh water from the Central Valley’s rivers meets salt water from tidal flow to the Delta from San Francisco Bay. Productive ecosystems have thrived in the Delta for millenia prior to California statehood. But for nearly a century now, engineers and others have frequently referred to the Delta as posing a “salt menace,” a “salinity problem” with just two solutions: either maintain a predetermined stream flow from the Delta to Suisun Bay to hydraulically wall out the tide, or use physical barriers to separate saline from fresh water into the Delta. While readily admitting that the “salt menace” results from reduced inflows from the Delta’s major tributary rivers, the state of California uses salt water barriers as a technological fix to address the symptoms of the salinity problem, rather than the root causes. Given complex Delta geography, these two main solutions led to many proposals to dam up parts of San Francisco Bay, Carquinez Strait, or the waterway between Chipps Island in eastern Suisun Bay and the City of Antioch, or to use large amounts of water—referred to as “carriage water”— to hold the tide literally at bay.
    [Show full text]
  • Municipal Water Quality Investigations Program History and Studies 1983—2012
    State of California The Resources Agency Department of Water Resources Municipal Water Quality Investigations Program History and Studies 1983—2012 November 2013 Edmund Brown Jr. John Laird Mark W. Cowin Governor Secretary for Resources Director State of California The Resources Agency Department of Water Resources State of California Edmund G. Brown Jr., Governor California Natural Resources Agency John Laird, Secretary for Natural Resources Department of Water Resources Mark W. Cowin, Director Laura King Moon, Chief Deputy Director Office of the Chief Counsel Public Affairs Office Security Operations Cathy Crothers Nancy Vogel, Ass't Dir. Sonny Fong Gov't & Community Liaison Policy Advisor Legislative Affairs Office Kimberly Johnston~ Dodds Waiman Yip Kasey Schimke, Ass't Dir. Deputy Directors Paul Helliker Delta and Statewide Water Management Gary Bardini Integrated Water Management Carl Torgersen State Water Project John Pacheco California Energy Resources Scheduling Kathie Kishaba Business Operations Division of Environmental Services Dean F. Messer, Chief Office of Water Quality Stephani Spaar, Chief Municipal Water Quality Program Branch Municipal Water Quality Investigations Section Cindy Garcia, Chief Rachel Pisor, Chief Ofelia Bogdan, Staff Services Analyst Prepared By Sonia Miller, Project Leader Otome J. Lindsey Foreword The Sacramento-San Joaquin Delta (Delta) is a major source of drinking water for 25 million people of the State of California. Therefore, the quality of Delta water is an important consideration for its use as a drinking water source. However, Delta water quality may be degraded by a variety of sources and environmental factors. Close monitoring of Delta waters is necessary to ensure delivery of high quality source waters to urban water suppliers.
    [Show full text]
  • Delta Cross Channel Fact Sheet
    U.S. Department of the Interior Bureau of Reclamation California-Great Basin Region Delta Cross Channel Overview The Delta Cross Channel (DCC), located near Walnut Grove, California, is a feature of Reclamation’s Central Valley Project (CVP) Delta Division. The facility is a gate-controlled diversion channel on the east bank of the Sacramento River, about 30 miles downstream of Sacramento. The DCC facilitates the diversion of fresh water from the Sacramento River into the interior Sacramento-San Joaquin River Delta to the CVP and State Water Project (SWP). Background Reclamation completed the DCC in January 1951. The facility is key to maintaining water quality in the central Delta during controlled releases from northern CVP storage reservoirs, such as Shasta and Folsom, through the Delta to the headworks of the CVP’s Delta-Mendota and Contra Costa canals and SWP’s California Aqueduct. The DCC, pictured above, is 6,000-feet long with a bottom width of 210 feet, and a capacity of 3,500 cubic feet per second (cfs). The gates extend about 245 feet across the channel at its mouth on the Sacramento River. Reclamation closes the DCC gates during high water to prevent flood stages in the San Joaquin section of the Delta. After flood danger passes, Reclamation opens the gates to allow Sacramento River water through to the federal and state pumping plants. During certain periods, When the gates are open, the DCC diverts fresh Sacramento River water to Snodgrass Slough. From there it flows through natural the DCC gates can operate frequently and boaters are channels to the CVP’s Jones Pumping Plant and SWP’s Banks advised to check gate status, especially around holidays.
    [Show full text]
  • California Highways and Public Works, March 1939
    I~ygPF Y "y~ff ~ s~{4 9l+~pP~: , ~ ~~ ' ` ` A mks „ ~`=;x ~~ .a. e 1 imx, .. ~ . t ~.. e-'~ ~~v~ f y f ~~ ~ CALIFORNIA HIGHWAYS AND PUBLIC WORKS Official Journal of the Division of Highways of the Department of Public Works, State of California FRANK W. CLARK, Director C. H. PURCELL, Stat¢ Highway Engineer J. W. HOWE, Edi4or K. C. ADAMS, Associate Edi4or Published for information of the m¢mbers of the d¢partment and th¢ citizens of California Editors of newspapers and others are privileged to use matter contained herein. Cu!s will be gladly loaned upon request Address communications to CaliFornia Highways and Public Works, P. O. Box 1499, Sacram¢nko, CaliFornia Vol. 17 MARCH, 1939 No. 3 Table of C'onterats Cover Page—Large center picture shows east sine of Shasta. dam site on Sacramento River, terraced by work roads where excavations for the dam foundations are under way. Surrounding scenes show diversion tunnel bore, drillers and equipment at work. Photos courtesy U, S. Bureau of Reclamation. Page Go~~ernor Olson Acts to Secure State Control aircl Operation of Shasta Water and Pa~uer---------------------------------------- 1 Sketch of Shasta Dam Sha«ping Po«per House,. Spill~~ay and Reservoir Lake 3 lIap of Central Valley Project Svstem_ 4 EYeavating Diversion Chaiznel for Sacramento River at Shasta Dam______ 5 Repairing Floocl Damage oi~ All-Year Yosemite. High~~ay_______________ 6 By If7. C. Fos~~czte, Dist~~tict Co~cst~~a~ct4o~ti Eai~z~aeer Picture of Rock Wall Flood Protection Construction on All-Year Yosemite Hi~;hi~~aY -------- ----------------------------- 7 Photo of Finished Section of Pock Wall _______ 8 $ 6,809,000 Cost to Modernize fIigh «~a~~~s in District ~__________________ 9 B~ R.
    [Show full text]
  • A Conceptual Model of Sedimentation in the Sacramento–San Joaquin Delta
    Peer Reviewed Title: A Conceptual Model of Sedimentation in the Sacramento–San Joaquin Delta Journal Issue: San Francisco Estuary and Watershed Science, 10(3) Author: Schoellhamer, David H., U.S. Geological Survey Wright, Scott A., U.S. Geological Survey Drexler, Judy, U.S. Geological Survey Publication Date: 2012 Publication Info: San Francisco Estuary and Watershed Science, John Muir Institute of the Environment, UC Davis Permalink: http://www.escholarship.org/uc/item/2652z8sq Acknowledgements: We thank David Fryberg, Denise Reed, Stuart Siegel, Mark Stacey, the DRERIP review panel, and the other DRERIP model authors for their assistance in developing this model. Justin Ferris, Mick van der Wegen, and two anonymous reviewers provided helpful comments on initial drafts of this manuscript. Keywords: Sediment, sediment transport, sedimentation, Sacramento – San Joaquin River Delta, conceptual model, feedback, open water, tidal marsh, watershed, vegetation, sea level rise, Central Valley Local Identifier: jmie_sfews_11152 Abstract: Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and marsh habitats. The model demonstrates feedback loops that affect the Delta ecosystem. Submerged and emergent marsh vegetation act as ecosystem engineers that can create a positive feedback loop by decreasing suspended sediment, increasing water column eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide.
    [Show full text]
  • Insights from the Sacramento–San Joaquin Delta, Technical Appendix
    A New Approach to Accounting for Environmental Water Insights from the Sacramento–San Joaquin Delta Technical Appendices CONTENTS Appendix A: A Brief Review of Regulatory Assignment of Water in the Sacramento–San Joaquin Delta Greg Gartrell and Brian Gray Appendix B: Water Assigned to Meeting Environmental Standards in the Delta from 1980–2016 Greg Gartrell, Jeffrey Mount, Ellen Hanak, Alvar Escriva-Bou, Brian Gray Supported with funding from the Dirk and Charlene Kabcenell Foundation, the S. D. Bechtel, Jr. Foundation, the US Environmental Protection Agency (with partial support from Assistance Agreement No.83586701), and the Water Foundation Appendix A Introduction In this appendix, we review the history of the water quality and flow standards that have governed the impoundment and diversion of water from the Sacramento–San Joaquin River and Delta system. Although most of the responsibility for complying with these standards falls on the two largest water-right holders—the federal Central Valley Project (CVP) and the California State Water Project (SWP)—this history begins well before their creation. It includes the early development of irrigated agriculture in the Delta and upstream in the Sacramento and San Joaquin River basins. It incorporates the design and operation of the two great water projects. And it concludes with the modern era of ecological protection and multifaceted water quality administration. Pre-Project Water Quality Issues Delta water salinity has posed challenges for water users—both within and upstream of the Delta—since the late 19th century. The Delta is an estuary.1 Salt moves from the San Francisco Bay into the Delta with the action of the tides; fresh water from the Sacramento and San Joaquin Rivers mixes with and dilutes brackish water in the western Delta and flows into the Carquinez Strait.
    [Show full text]
  • NOAA Pacific Charts Catalog Reference
    PANEL A PANEL E 19380 156° 158° 160° S 122° TR 123° A 49° IT CANADA 49° O F SEMIAHMOO BAY UNITED S TATES 19381 GE Blaine Hawai‘ian Islands K 19385 O Point Roberts A RG 18423 U IA Chart Number Title Scale L Hanalei NORTH PACIFIC OCEAN A K 19320 Island of Hawai‘i 1:250,000 A H S 19322 Harbors & Landings on the Northeast & Southeast Coasts of Hawai‘i 22° I KAUA‘I 22° altspring 18421 C 19384 Honokaa Landing 1:2,500 H Waimea 19340 Ni‘ihau A N Honu‘apo Bay 1:2,500 N 19383 E 19386 Kukuihaele Landing 1:2,500 L 19382 Punalu‘u Harbor 1:2,500 19357 I 18424 Kahuku Point sland 19324 Island of Hawai‘i—Hilo Bay 1:10,000 AI CHANNEL 19326 Pa‘auhau Landing—Island of Hawai‘i 1:5,000 Ka‘ula U KA Ka‘ena Point 19327 West Coast of Hawai‘i—Cook Point to Upolu Point 1:80,000 18430 19359 ASS Honokohau Harbor 1:5,000 YP Bellingham Cowichan Bay O‘AHU B Keauhou Bay 1:5,000 19361 19367 E BOUNDAR L 18431 L 19329 Mahukona Harbor and Approaches—Island of Hawai‘i 1:5,000 19366 I 19330 Kawaihae Bay—Island of Hawai‘i 1:10,000 HONOLULU EL N N Sidney G N H 19331 Kailua Bay—Island of Hawai‘i 1:5,000 A 19358 H Orcas I A C 18424 M 19332 Kealakekua Bay to Honaunau Bay 1:10,000 19362 19369 I T W NEL 18432 I B I MO AN A 19340 Hawai‘i to O‘ahu 1:250,000 L H HAR A A OKAI OC OCHE R Y ‘ OL R T K IL S 19341 Hana Bay—Island of Maui 1:5,000 19353 PA 19342 HARBOR O O I 19342 Kahului Harbor and Approaches 1:30,000 19353 UI HARBOR R S A S Kahului Harbor 1:10,000 KAHUL TRAIT 19380 19348 O LANA‘I Friday Harbor R 19347 Channels between Moloka‘i, Maui, Lana‘i and Kaho‘olawe 1:80,000 18427 San
    [Show full text]
  • Datum Errors for West Coast of the United States (California, Oregon, Washington)
    Tidal Datum Errors for West Coast of the United States (California, Oregon, Washington) Standard deviation (or accuracy) of Tidal Datum Computations: The time period necessary to incorporate all of the major astronomical tide producing cycles into the computation of a tidal datum is 19-years. All tidal datums are referenced to specific 19-year National Tidal Datum Epochs (NTDE). First reduction tidal datums are determined directly by averaging values of the tidal parameters over a 19-year NDTE. Errors in determination of tidal datums using First Reduction for the 19-year NTDE are theoretically zero. NTDE datums for short-term subordinate stations are computed and adjusted to a 19-year NTDE equivalent using simultaneous comparison with an appropriate nearby control station (NOS, 2003, Swanson, 1974, and Marmer, 1951). See Gill and Fisher, 2008: http://tidesandcurrents.noaa.gov/publications/Technical_Memorandum_NOS_COOPS_0048.pdf for the areas of coverage for tidal datum computation for each National Water Level Observation Network (NWLON) control tide station. Errors in determination of tidal datums at short-term stations through the method of simultaneous comparison are known to be generally correlated with the length if the subordinate station observations, with geographic distance from the control station and with difference in range of tide and time of tide between control and subordinate stations. In applied research performed by Bodnar (1981), multiple curvilinear regression equations estimating the accuracy of computed 19-year equivalent tidal datums were developed. The formulas for Mean Low Water were adopted for use in estimating tidal datum errors because the low water differences express the effects of shallow water and bottom friction better than MHW.
    [Show full text]
  • 2. the Legacies of Delta History
    2. TheLegaciesofDeltaHistory “You could not step twice into the same river; for other waters are ever flowing on to you.” Heraclitus (540 BC–480 BC) The modern history of the Delta reveals profound geologic and social changes that began with European settlement in the mid-19th century. After 1800, the Delta evolved from a fishing, hunting, and foraging site for Native Americans (primarily Miwok and Wintun tribes), to a transportation network for explorers and settlers, to a major agrarian resource for California, and finally to the hub of the water supply system for San Joaquin Valley agriculture and Southern California cities. Central to these transformations was the conversion of vast areas of tidal wetlands into islands of farmland surrounded by levees. Much like the history of the Florida Everglades (Grunwald, 2006), each transformation was made without the benefit of knowing future needs and uses; collectively these changes have brought the Delta to its current state. Pre-European Delta: Fluctuating Salinity and Lands As originally found by European explorers, nearly 60 percent of the Delta was submerged by daily tides, and spring tides could submerge it entirely.1 Large areas were also subject to seasonal river flooding. Although most of the Delta was a tidal wetland, the water within the interior remained primarily fresh. However, early explorers reported evidence of saltwater intrusion during the summer months in some years (Jackson and Paterson, 1977). Dominant vegetation included tules—marsh plants that live in fresh and brackish water. On higher ground, including the numerous natural levees formed by silt deposits, plant life consisted of coarse grasses; willows; blackberry and wild rose thickets; and galleries of oak, sycamore, alder, walnut, and cottonwood.
    [Show full text]
  • Flood Contingency Public Safety
    PUBLIC SAFETY FLOOD CONTINGENCY N ' 121°39'W 121°38'30"W 121°38'W 121°37'30"W 121°37'W 121°36'30"W 121°36'W 121°35'30"W 121°35'W 121°34'30"W 121°34'W 121°33'30"W 121°33'W 2 N ' 121°39'W 121°38'30"W 121°38'W 121°37'30"W 121°37'W 121°36'30"W 121°36'W 121°35'30"W 121°35'W 121°34'30"W 121°34'W 121°33'30"W 121°33'W ° 2 8 ° N 3 ' 8 2 N 3 ' C ° 2 8 a C ° 3 n a 8 a Holland Tract n 3 l 1 a Holland Tract 8 l 1 0 8 + 0 R 0 RD 2025 + d Frank's Tract 0 R 0 RD 2025 d Frank's Tract 0 The symbology presented in the legend below is global to the The symbology presented in the legend below is global to the project area, some symbols may not be present on map project area, some symbols may not be present on map H5 d R d r R TRANSPORTATION TRANSPORTATION r e H3 e QUIMBY ISLAND p N i " Gate p 0 Gate N i " 3 P ' 0 0 1 0 + 3 P ° 0 ' 16 N " 8 1 RD 2090 ° 0 3 N ROADS " 8 3 ' 0 ROADS 3 1 3 ° 2 ' 8 1 1 ° 0 3 2 1 8 BETHEL SL + QUIMBY ISLAND 3 I AND 0 0 0 BETHEL ISLAND + 0 H 0 Major Local Trail, 150+0 Major Local Trail, 0 0 Interstate Highway Trail MUNICIPAL ID 2 RD 2090 Interstate Highway Trail 150+0 Road Road Major 2 o Road Road Major 2 0 MUNICIPAL ID 2 + 0 0 l + H2 0 0 H h l 0 H Gate a way Rd g Ga o a ylo r u te way Rd PS T n o FFM ylo r l R l Ta l FLOOD CONTINGENCY OPTIONS d d S 2 LEVEE INFORMATION Rd a 4 A FFM C N ' d 0 A D D 1 + 0 N 0 ' n u ° n 30+ Flood Contingency Special Flood 0 1 1000-Foot Levee Stationing 1 8 00 ° + 0 t N 0 3 2 3 u ' 300+00 290+00 1 8 d 1 5 N 3 2 Option Consideration o ' 0 ° PS 5 1 8 Levee Centerline + 0 C ° d M 3 R 0 + H3 8 d 3 Effluent
    [Show full text]