Lemons Save the Day!

Construction of the Rancho Santa Fe Residence project site was just recently completed.  This beautiful single-family estate is located on six acres in Rancho Santa Fe, CA.  The project consisted of reconstruction of the home and driveway and adding a new barn and pasture.  The exterior grounds of the property slope radially down away from the home and have historically been utilized for agriculture with numerous rows of lemon trees. 

Plan revisions since its initial approval in 2015 required the project to implement stormwater treatment measures consistent with the County’s latest Hydrology and BMP requirements.  The revised plan and selected BMPs were required to address peak flow increases, stormwater treatment, and flow control hydromodification.  Detention and treatment facilities typically consist of either expensive modular units or large basins which, for this site would have required significant grading and removal of numerous trees.  In assessing the various BMP options available and in coordination with County staff,  SDE determined to salvage the site’s existing lemon tree orchard and utilize the surrounding area for biofiltration treatment.

By modifying the area surrounding the existing lemon trees, the trees now function as ‘Tree Wells’ in accordance with the County’s BMP Manual.  Also, by adding rows of berms, a tiered layout was created to allow detention to occur in order to mitigate for peak flow runoff increases.  This design strategy  offered significant benefits over typical stormwater measures such as salvaging the existing trees as well as lower associated maintenance cost.  Additionally, since no structural BMP facilities are being constructed, a maintenance agreement with the County was not required.