Flood and Stormwater Protection


RMC has been at the forefront of developing ecologically sound and forward-thinking watershed approaches to flood protection that improve water quality and reduce flooding.

Llagas Creek rendering

Upper Llagas Creek Flood Protection

Santa Clara Valley Water District

RMC is providing project management and design services for a flood protection improvement project along 13.6 miles of Upper Llagas Creek. The project involves complete engineering design of channel improvements, including concrete walls, levees, culverts, and floodwalls. RMC is leading a team of 12 subconsultants to develop a design that:

  • Protects Morgan Hill residents and businesses from a 100-year flood event while supporting the City’s vision for its downtown redevelopment plans
  • Meets the” Clean Safe Creeks” goals and objectives with a natural flood protection design acceptable to project stakeholders and regulatory agencies
  • Produces construction documents adhering to U.S. Army Corps of Engineers and Water District design standards
  • Identifies strategies to reduce costs

Petaluma after storm (image wikicommons; Robert Campbell)

Upper Petaluma River Watershed Flood Protection Project

Sonoma County Water Agency

For the Upper Petaluma River Watershed Flood Control Project, RMC completed a scoping study to develop stormwater management or groundwater recharge projects that provide flood hazard reduction and groundwater benefits within the Upper Petaluma River Watershed. This initial phase of work included:

  • Outreach to the public
  • Definition of goals and objectives
  • Identification of project concepts and potential implementation location
  • Reviewing project concepts developed by local agencies and providing an opinion about each project’s feasibility

Malibu Legacy Park with homes in distance

Malibu Legacy Park Integrated Stormwater, Wastewater, and Recycled Water Project

City of Malibu

RMC planned and designed the Legacy Park project—a multi-benefit clean water project that improves water quality and protects and restores natural resources. RMC:

  • Incorporated vegetated stormwater detention basins, intermittent wetlands, and riparian habitat on 15 acres
  • Developed innovative system to convey pollutant-loaded stormwater away from Malibu Creek and into the City’s stormwater treatment facility
  • Successfully obtained a $2-million grant for the stormwater treatment system
  • Coordinated with Los Angeles County on standards for stormwater reuse and separation criteria
  • Developed a continuous simulation model to determine pumping improvements and detention basin sizing required to meet Pathogen TMDL requirements

Click here to learn more about the Legacy Park in a detailed PDF about additional park features and highlights.

Low Impact Development in San Francisco

Low Impact Design

San Francisco Public Utilities Commission

RMC helps achieve sustainable storm water management through low impact design (LID) approaches that can help mitigate the effects of urbanization on stormwater. We completed two LID projects for San Francisco where we:

  • Strategized where integrating LID into various streetscape initiatives would reduce the volumes and peak flows of stormwater entering the combined sewer system, alleviate flooding, and contribute to neighborhood greening
  • Developed conceptual design for the number, type, location, and size of LID features that could reasonably be implemented
  • Identified potential opportunities for coordination with other City programs

West Antioch Creek

West Antioch Creek Channel Improvements

City of Antioch

RMC performed hydraulic modeling and developed design drawings to improve the conveyance capacity of West Antioch Creek. RMC designed capacity improvements to relieve an undersized culvert and creek channel subject to significant and frequent flooding that significantly impacts nearby residences and businesses. The project also included removing sediment from the downstream portion of the creek. RMC was responsible for developing the design drawings and specifications, obtaining permits, and coordinating with the City’s CEQA consultant.