Leucadia Area Watershed Master Plan

Project Description

Client: City of Encinitas
Location: Encinitas, CA

Q3 Consulting, a PROACTIVE company, is providing engineering services to provide stormwater services to complete a Master Plan of Drainage for the City of Encinitas. A major portion of the City frequently floods during moderate storm events due to existence of multiple low points or sumps within the City. Environmental regulations and previously proposed facility costs have deemed improvements infeasible. As a result, the City hired Q3 to prepare advanced stormwater models to identify more feasible flood control solutions. As an environmentally proactive City, “green infrastructure” was important for any proposed solution.

The project involved utilizing a new method of calculating hydrology and hydraulics driven by linking GIS databases. Q3 reviewed and updated the City’s storm drain layers by reviewing as-built data and supplementing with field verification. Using GIS soils data, land use data, drainage infrastructure data and a water quality data, a comprehensive XPSTORM base model was prepared. The models were validated against actual storm events and compared to known flood elevations, photos, and videos. Once validated, the models were used to define proposed drainage solutions that included green and grey infrastructure.

One of the priority regions had been studied multiple times previously; however, proposed improvements proved too expensive. With the use of a linked 1-&2-dimensional hydrology/hydraulic model, Q3 successfully identified a more feasible solution that provided flood control and green infrastructure for a 2-mile stretch of Highway 101 and the areas surrounding it. The proposed solution was approved by the City Council unanimously to move into final design.