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Santa Maria River Levee Repair Project

The Santa Maria River Levee Repair Project included correction of design deficiencies on the existing Santa Maria River Levee, so that the U.S. Army Corps of Engineers (Corps) could certify the levee as capable of providing flood protection under 100-year flood conditions, the boundaries of which are determined by the Federal Emergency Management Agency (FEMA). In response to a request from FEMA to certify the levee, the Corps conducted research and analysis of the levee, determining that there was a reasonable certainty that this levee system would not contain the 100-year flood, or the magnitude flood with a one percent chance of occurring each year. Therefore, the project was developed to correct these deficiencies and facilitate certification.

Aspen prepared a joint Environmental Assessment (EA) / Mitigated Negative Declaration (MND) for the project, located in Santa Barbara and San Luis Obispo Counties, California. This work provided the required National Environmental Policy Act and California Environmental Quality Act (CEQA) documentation for the levee improvements, which consisted of using a soil cement revetment from the crest of the levee down to 15 feet below the thalweg of the low-flow channel. This revetment occurred along three reaches of the south levee for 7.1 miles, extending from the east side of the Santa Maria City Landfill to the north end of Blosser Road, where safety was at highest risk.

The Draft EA was released for a 30-day public review period and notice was filed with the State Clearinghouse. An Initial Study was prepared in compliance with CEQA for use by State agencies to issue applicable permits; the Initial Study was included as an appendix to the EA. A detailed Mitigation Monitoring Plan were also included in the Final EA/MND. In addition, Aspen conducted biological surveys, including vegetation mapping, rare plants, and sensitive wildlife. Vegetation communities were identified using aerial photography and field verified using GPS data collection. This data was downloaded to CADD software and vegetation maps were created.

Practice areas: Infrastructure and Public Works

Services provided for this project: