San Elijo Lagoon Inlet Facing Possible Closure

Sand has refilled the channel, and the lagoon is struggling to flush water out

As dedicated stewards and managers, the Nature Collective staff have been monitoring the inlet since the recent dredging, and our observations indicate a steady decline in the tide’s ability to flow in and out of the lagoon. Sand has refilled the channel, and the lagoon is struggling to flush water out, resulting in elevated water levels.

The lagoon is now caught between two determining environmental factors expected this weekend, which will determine whether it remains open but still muted or if it closes: 

-Expected surf height of 6-8 feet, and the wave energy that comes with it could move enough sand to fully block the channel.

-Coastal areas are expecting up to 2 inches of rain. If we receive enough, the momentum of the resulting storm flow down the Escondido Creek could create enough hydraulic force to push some of the sand out, delaying the inlet closure.

Our data and pro bono engineering expertise suggest two likely culprits or a combination of the two:

#1 During the recent dredging project, a 20-foot strip of sand could not be removed from the channel due to a 10-foot safety margin on each side and above a gas line that runs under the lagoon channel. The project modeling predicted that the tides would flatten this sand strip, thereby not impeding tidal flow. However, this flattening may not have occurred, and this sand strip may be potentially blocking the water flow out of the lagoon.  

#2 The rate of sand entering the inlet is higher than modeled, possibly due to a major sand replenishment project just north of the inlet in Leucadia.

Solving this problem requires immediate help from SANDAG, which holds the fiduciary responsibility for monitoring and adaptive management of the San Elijo Lagoon Restoration project. Unfortunately, essential monitoring was halted in April due to an issued stop-work order, allowing the budgeted funds to support the aquatic dredging.

The lack of committed agency funding for this emergency work is hindering the implementation of a solution. If the inlet closes, the resulting drop in dissolved oxygen and prolonged flooding will swiftly threaten marine life and critically impact habitats for endangered species.

We’ll keep you posted as this situation develops.