100-Year Flood – It’s All About Chance
Floodplain farm fields provide novel rearing habitat for Chinook salmon$0.00 Bulk Download
Floodplain farm fields provide novel rearing habitat for Chinook salmonPLOS One | June 7, 2016...Summary
When inundated by floodwaters, river floodplains provide critical habitat for many species of fish and wildlife, but many river valleys have been extensively...
When inundated by floodwaters, river floodplains provide critical habitat for many species of fish and wildlife, but many river valleys have been extensively leveed and floodplain wetlands drained for flood control and agriculture. In the Central Valley of California, USA, where less than 5% of floodplain wetland habitats remain, a critical conservation question is how can farmland occupying the historical floodplains be better managed to improve benefits for native fish and wildlife.
In this study fields on the Sacramento River floodplain were intentionally flooded after the autumn rice harvest to determine if they could provide shallow-water rearing habitat for Sacramento River fall-run Chinook salmon (Oncorhynchus tshawytscha). Approximately 10,000 juvenile fish (ca. 48 mm, 1.1 g) were reared on two hectares for six weeks (Feb-March) between the fall harvest and spring planting. A subsample of the fish were uniquely tagged to allow tracking of individual growth rates (average 0.76 mm/day) which were among the highest recorded in fresh water in California. Zooplankton sampled from the water column of the fields were compared to fish stomach contents. The primary prey was zooplankton in the order Cladocera, commonly called water fleas.
The compatibility, on the same farm fields, of summer crop production and native fish habitat during winter demonstrates that land management combining agriculture with conservation ecology may benefit recovery of native fish species, such as endangered Chinook salmon.
Novato Creek Baylands Historical Ecology Study$0.00 Bulk Download
Novato Creek Baylands Historical Ecology StudySan Francisco Estuary Institute | July 31, 2015...Summary
Over the past century and a half, lower Novato Creek and the surrounding tidal wetlands have been heavily modified for flood control and...
Over the past century and a half, lower Novato Creek and the surrounding tidal wetlands have been heavily modified for flood control and land reclamation purposes. Levees were built in the tidal portion of the mainstem channel beginning in the late 1800s to convey flood flows out to San Pablo Bay more rapidly and to remove surrounding areas from inundation. Following levee construction, the wetlands surrounding the channel were drained and converted to agricultural, residential, and industrial areas. These changes have resulted in a considerable loss of wetland habitat, reduced sediment transport to marshes and the Bay, and an overall decreased resilience of the system to sea level rise.
In addition to tidal wetland modification, land use changes upstream in the Novato Creek watershed have resulted in several challenges for flood control management. Dam construction and increased runoff in the upper watershed have resulted in elevated rates of channel incision, which have increased transport of fine sediment from the upper watershed to lower Novato Creek. Channelization of tributaries and construction of irrigation ditches have likely increased drainage density in the upper watershed, also potentially contributing to increased rates of channel incision and fine sediment production (Collins 1998). Downstream, sediment transport capacity has been reduced by construction of a railroad crossing and loss of tidal prism and channel capacity associated with the diking of the surrounding marsh. As a result of the increased fine sediment supply from the watershed and the loss of sediment transport capacity in lower Novato Creek, sediment aggradation occurs within the channel, which in turn reduces the flood capacity of the channel, necessitating periodic dredging (fig. 1; Collins 1998, PWA 2002).
Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco Bay$0.00 Bulk Download
Analysis of the costs and benefits of using marsh restoration as a sea level rise adaptation strategy in San Francisco BayThe Bay Institute | February 22, 2013...Summary
The purpose of this study is to examine opportunities to protect San Francisco Bay’s recovering tidal marsh ecosystems while helping bayshore communities to...
The purpose of this study is to examine opportunities to protect San Francisco Bay’s recovering tidal marsh ecosystems while helping bayshore communities to manage the impacts of sea level rise. Specifically, it considers the flood risk management functions that tidal marshes perform naturally and evaluates the possibility of integrating those functions into a co-beneficial shoreline management strategy. The study’s intended audience is planners, politicians, regulators, and other stakeholders with the authority to make or affect decisions that influence the configuration and use of the San Francisco Bay shoreline. The study examines the current functions of San Francisco Bay tidal marshes as well as existing flood risk management strategies. It considers how environmental conditions are likely to change in the era of climate change, and how we can adapt our marshes and our flood risk management practices to accommodate these changes.
State Plan of Flood Control Descriptive Document 2016 Update$0.00 Bulk Download
State Plan of Flood Control Descriptive Document 2016 UpdateCalifornia Department of Water Resources (DWR) | December 14, 2016...Summary
The November 2016 State Plan of Flood Control (SPFC) Descriptive Document Update (2016 Update) is intended to serve as a reference for flood...
The November 2016 State Plan of Flood Control (SPFC) Descriptive Document Update (2016 Update) is intended to serve as a reference for flood management planners and operators at the local, State, and federal levels. It is not a stand-alone document; rather, it works in conjunction with the November 2010 SPFC Descriptive Document, builds upon information presented in the original report, and documents changes to the SPFC that have occurred between November 2010 and July 2016.
The 2016 Update documents the inventory of flood control projects and works (facilities), lands, programs, plans, conditions, and mode of operations and maintenance for the State-federal flood management system in the Sacramento River and San Joaquin River watersheds of California, as well as informs the 2017 Central Valley Flood Protection Plan Update.
In 2006 and 2007, California voters approved the Disaster Preparedness and Flood Prevention Bond Act of 2006 and the Central Valley Flood Protection Act of 2008 respectively. These acts defined the Sacramento River and San Joaquin River federal-State flood control projects as the SPFC, and required DWR to develop, and the Central Valley Flood Protection Board to adopt, a Central Valley Flood Protection Plan. The Central Valley Flood Protection Plan is broader than the SPFC, affecting the entire watersheds of the Sacramento and San Joaquin valleys.
A complex system of dams and reservoirs, levees, weirs, bypasses, and other features constructed piecemeal over the last 100 years protects urban and rural areas against most flooding. This system has prevented billions of dollars in damage in its lifetime. A portion of this complex flood protection system includes State and federally authorized projects for which the Central Valley Flood Protection Board or DWR has provided assurances of cooperation to the federal government, known as the SPFC. These statutory authorizations include provisions regarding responsibility for operation and maintenance of the flood control facilities.
The California Legislature has authorized funding for numerous flood control projects throughout the Sacramento and San Joaquin River watersheds. As the SPFC evolves, updates to the SPFC Descriptive Document will be useful in determining funding eligibility for funding for facility improvements.
RELATED DOCUMENT: State Plan of Flood Control (2010)