Sediment Transport & Erosion Control

San Elijo Lagoon Sediment Transport Modeling Study | San Diego County, California

San Elijo Lagoon |
San Elijo Lagoon |
Caltrans District 11
Project Description:
San Elijo Lagoon is an estuary near the City of Encinitas, and many stakeholders in the area surrounding the lagoon have expressed concern regarding its value as a habitat. The project proposed to widen the US 101 bridge, Union Pacific Railroad (UPRR) bridge and the Interstate 5 bridge to provide better tidal/freshwater circulation; therefore, improving the water quality of San Elijo Lagoon.

Three embankments cut across the lagoon under existing conditions; one for South Coast US 101, one for North County Transit District railroad and one for Interstate 5. These embankments play a significant role in defining flow and sedimentation patterns in the lagoon. Caltrans considered replacements for one or more of the bridge embankments. As part of the Project Team, WRECO was tasked to investigate what effect the various replacement alternatives would have on sediment transport in the lagoon including the peak storm-related scour and aggradation, as well as long-term bed evolution.

WRECO was also responsible for preparing a set of sedimentation model scenarios and preparation of a technical report describing the study findings. WRECO performed all sedimentation modeling using the HEC-6 sedimentation and bed evolution modeling system developed by the U.S. Army Corps of Engineers. The model study included scenarios depicting existing conditions and conditions that would results from either of two proposed conceptual bridge replacement alternatives.

Key Tasks:
Sedimentation Study and Modeling
UPRR Bridge
UPRR Bridge
To request more information regarding WRECO's sediment transport and erosion control projects, email us at

WRECO | Contact: | |