Anticipatory Erosion Control Program

Overview

The Anticipatory Erosion Control Program (AECP) is intended to proactively maintain the Sacramento Region’s level of flood protection by controlling erosion that threatens flood control levees. Key to this program is identifying and treating sites exhibiting early signs of erosion that have not yet encroached into the projected foundation of federal-state levees. This approach is an alternative to traditional approaches to bank protection such as the Federal-State Sacramento River Bank Protection Program (SRBPP) which is typically implemented once erosion encroaches into the projected foundation of a levee and often requires large quantities of rock to protect the levee and repair the eroded bank.

The goal of the AECP is to significantly reduce the direct dollar and environmental costs of bank protection by safeguarding levees through the preservation of vegetated riverside berms using a combination of bioengineering methods. In the metropolitan Sacramento Region, riverside berms contain the remnants of a once extensive riparian corridor and are considered critical habitat for listed anadromous fish. These berms also provide a first line of protection to the urban levee system by acting both as a physical buffer and by lengthening underseepage pathways to an adjacent levee.

The AECP relies on considerably less rock and a combination of methods and materials including cobble/riprap, brush boxes, soil fill, brush mattresses and native vegetation. These methods have proven successful in many applications and are environmentally and aesthetically appealing. One example is the Sand Cove Streambank Restoration Project described below.

Sand Cove Streambank Restoration Project

Sand Cove, located along the east bank of the Sacramento Riveris approximately 1.5 miles upstrem of the American River confluence, is an excellent example of the benefits that can be realized by the AECP. This project was a cooperative venture among the City of Sacramento Parks Department, US Army Corps of Engineers, Reclamation District 1000, and SAFCA. The goal of the project was to solve and remediate a severely eroded bank to protect important natural resources and recreational amenities in the area. The site is approximately 700 feet long and was vulnerable to boat wave erosion due to its proximity upstream of a marina ‘no wake zone’.

New and innovative designs elements were incorporated into the Sand Cove project including: a small riprap bench along the toe of the bank to attenuate wave energy at the summer water surface elevation; the use of large quantities of soil fill (instead of riprap) to rebuild the eroded bank; and approximately 200 highly resinous (slow decomposing) pistachio trees, anchored onto the bench to provide Instream Woody Material (IWM) to enhance aquatic habitat. The site was planted in the late fall of 2005 and vegetation growth has been vigorous and self sustaining in less than two years. The site is also self mitigating and has compensated for any adverse temporal impacts associated with project construction. Click the link below to see a cross section of the engineering design and a time line of pictures taken at Sand Cove prior to construction and through various stages of development (Sand Cove Pictures).