California Civil Design Group, Inc. has literally decades of extensive experience in the design and analysis of storm drain and flood control facilities, including pipe systems, culverts, improved and unimproved channels, detention/ retention/infiltration basins, percolation and spreading basins, debris basins, ponds, streams, dams, levees, and weirs.
The majority of development projects require the preparation of a Hydrology & Hydraulics Study. These studies are the backbone of the services provided by our Water Resources Department, and involve the examination of existing hydrology conditions versus proposed or developed conditions to determine the correct sizing and implementation of storm drain facilities.California Civil Design Group, Inc. uses the hydrology and hydraulics software developed by our sister company, CivilDesign® Corporation, to perform the calculations necessary for these studies.
Large-scale developments may require the preparation of a comprehensive Drainage Master Plan (examples include Master Planned Communities, Specific Plan Areas, and cities requiring a new or revised Hydrology Study for all or a significant portion of the city itself). These Master Plans generally do not include the level of detail characteristic of a singular development, but rather provide the general calculations necessary to locate and design large-capacity channels, flood control basins, and other regional drainage facilities.
When a development is proposed within an identified floodplain, the Federal Emergency Management Agency (FEMA) often requires a Letter of Map Revision (LOMR) and/or Conditional Letter of Map Revision (CLOMR) for the project. These documents require a floodplain analysis to substantiate how proposed improvements will alter the delineation of the existing floodplain and subsequently protect the development from potentially catastrophic floodwaters.
The California State Water Resources Control Board (SWRCB) Santa Ana River Regional Office requires the majority of development projects within the Santa Ana River Watershed to prepare a Water Quality Management Plan (WQMP) that identifies and designs the post-construction Best Management Practices (BMPs) and associated Operations and Maintenance (O&M) activities for the project. These BMPs are designed to reduce the impact of the project’s storm water runoff to the existing municipal storm drain system as well as treat the storm water for pollutants prior to release from the site.
While the WQMP addresses post-construction storm water treatment and mitigation, the Storm Water Pollution and Protection Plan (SWPPP) addresses BMPs during the construction phase of a project. Almost all construction projects are required by the State of California to prepare a SWPPP as well as a Notice of Intent (NOI) to satisfy National Pollutant Discharge Elimination System (NPDES) requirements.