Even though we have completed almost 100 water quality projects in San Diego, it is still satisfying to reach approval on the design of another one.  Our most recent project, a 14 unit apartment “in-fill-project” located in eastern San Diego.  The project was designed by another civil engineer and Earth Wind Water Civil Engineering was retained to bring the water quality analysis and design to the project.

It is very common for us to work with other design engineers on these projects, stated Dan S Biggs, company lead civil engineer.  That is because these regulations covering water quality/pollution prevention are constantly evolving in Southern California and if you don’t do them often, you easily become out-dated.  This project had enough impervious areas in its improved design that it became what the agency calls a “priority development project”.  When this occurs – your project faces the full-force of the regulations.  You then need to prepare onsite facilities to clean the stormwater using some sort of biological filtration.  Then after that, you must detain the stormwater by an amount called the “Design Capture Volume”.  Even after doing all of this, you still face the most demanding requirement – you must capture the stormwater and then release it so as it leaves the
project site it is equal to or less than the amount of
runoff from the site when it existed in its “natural state”.

A summary of critical tasks performed by our team includes these:

  • Hydrology Study (2-year storm, 10-year storm, 100-year storm),
  • LID Site Analysis,
  • Comparative Imperviousness Analysis,
  • Point-source Pollution Analysis,
  • Pollutant Removal Analysis & BMP Design (using fully lined biofiltration basins),
  • Restorative Hydromodification Analysis & Design (detention using tank/vaults), and
  • Site Permanent BMP Operations and Maintenance Report.