A More Eco-Friendly Approach to Flood Protection
For the past 40 years, the Valley has relied primarily on channelized arroyos, many of them concrete, to convey stormwaters through the area and out to the Bay as quickly as possible.
But the new, more environmentally friendly Stream Management Master Plan's vision over the next three decades is to create a flood-protection program that relies largely on using the future Chain of Lakes, a series of mined-out gravel pits between Livermore and Pleasanton, to detain stormwater in the Valley. The stored water would be released downstream only after storms pass through the area, meaning arroyos can be kept in a more natural state than under the channelization method.
Not only significantly less expensive when it comes to flood control, this technical approach also affords opportunities to:
improve our water supply through groundwater recharge
enhance arroyo water quality and habitat
increase the connectivity of trails and recreational opportunities in the Valley
promote public understanding of our watershed through educational programs
Of the 45 conceptual projects identified in the SMMP, 10 would remove or modify fish-passage barriers in Arroyo Mocho, Arroyo del Valle and Arroyo de la Laguna. Others would restore natural stream flows, replace plants with native types, stabilize stream banks, create wetlands and other habitat for sensitive species, and install trails and educational kiosks near Valley arroyos.
- To view the SMMP document, click here.
- To view an SMMP brochure, click here.
- To view an SMMP video, click here.
For the flood-protection portion of the SMMP, a development impact fee apportions to new development -- not to existing residents and businesses -- the share of costs of those improvements needed specifically to manage the additional stormwater runoff generated by new development so that development pays its fair share. The share of costs for flood protection unrelated to new development will come from existing users or grants.
For a copy of a adopted Development Impact Fee Ordinance (DIF), which took effect in 2009, click here.
More About the SMMP
In 2011, Zone 7 laid the groundwork for updating its Stream Management Master Plan. The update will address new California Environmental Quality Act (CEQA) requirements for climate change analysis and incorprorate recent watershed-wide changes, including potential steelhead access to the northern part of the Alameda Creek Watershed. This update will also help facilitate any future revisions to the DIF. As part of the SMMP update, Zone 7 staff focused in 2011 on creating, calibrating and running new service area hydrologic and hydraulic models; investigating innovative techniques for stormwater management, including enhancing natural floodplains and vegetated stormwater channels; and applying for grants.
In addition, Zone 7, in partnership with the Urban Creeks Council, was awarded a $190,000 grant in Novemer 2011 from the California State Coastal Conservancy for environmental studies in the watershed to assist in the update of the SMMP and subsequent update of the DIF. The grant provides money to conduct studies of existing bird and fish populations, help guide stream corridor design decisions, and provide Zone 7 with some of the information needed to address climate change in upcoming CEQA analysis, as is now required under state law.
Zone 7 and the City of Livermore have collaborated to integrate the SMMP and the El Charro Specific Plan. In 2011, Zone 7 finalized a $10 million partnership agreement with the City for flood protection improvements within the El Charro Specific Plan Area, and the city completed a majority of the improvements. These improvements are intended to function in conjunction with the regional flood control system.
To view Zone 7's main page for Flood Protection & Stream Management, click here.