The San Francisco Bay Conservation and Development Commission (BCDC), in continued partnership with the San
Francisco Bay Long Term Management Strategies (LTMS) Agencies, is undertaking the development of a Regional
Sediment Management Plan for the San Francisco Bay estuary and its watershed (estuary). Regional sediment
management (RSM) is the integrated management of littoral, estuarine, and riverine sediments to achieve balanced
and sustainable solutions to sediment related needs. Regional sediment management recognizes sediment as a
resource. Sediment processes are important components of coastal and riverine systems that are integral to
environmental and economic vitality. It relies on the context of the sediment system and forecasting the long-range effects of management actions when making local project decisions.
In the San Francisco Bay estuary, the sediment system includes the Sacramento and San Joaquin delta, the bay, its
local tributaries and the near shore coastal littoral cell. Sediment flows from the top of the watershed, much like
water, to the coast, passing through rivers, marshes, and embayments on its way to the ocean. Like water, sediment
is vital to these habitats and their inhabitants, providing nutrients and the building material for the habitat itself.
When sediment erodes excessively or is impounded behind structures, the sediment system becomes imbalanced,
and rivers become clogged or conversely, shorelines, wetlands and subtidal habitats erode. The sediment system
continues to change in response both to natural processes and human activities such as climate change and shoreline
development. Human activities that influence the sediment system include flood protection programs, watershed
management, navigational dredging, aggregate mining, shoreline development, terrestrial, riverine, wetland, and
subtidal habitat restoration, and beach nourishment.
As observed by recent scientific analysis, the San Francisco Bay estuary system is changing from one that was
sediment rich to one that is erosional. Such changes, in conjunction with increasing sea level rise due to climate
change, require that the estuary sediment and sediment transport system be managed as a single unit. To better
manage the system, its components, and human uses of the system, additional research and knowledge of the system
is needed. Fortunately, new sediment science and modeling tools provide opportunities for a vastly improved
understanding of the sediment system, predictive capabilities and analysis of potential individual and cumulative impacts of projects. As science informs management decisions, human activities and management strategies may need to be modified to protect and provide for existing and future infrastructure and ecosystem needs. (PDF contains 3 pages)
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