Resilient Wetlands

San Luis Rey River Estuary

The San Luis Rey River originates in the Palomar and Hot Springs Mountains in eastern San Diego County. Water from several tributaries is collected behind the dam at Lake Henshaw. The river extends over 55 miles across northern San Diego County before discharging to the Pacific Ocean in the City of Oceanside. The River drains a watershed of approximately 360,000 acres or 562 square miles.

There are numerous land use types within the watershed with the majority of land remaining undeveloped. Higher population concentrations are in the western area of the watershed. Residential and agriculture serve as the dominant land uses in the watershed.

The river flows through hilly agriculture and low-density residential areas for most of its length. Soon after entering the City of Oceanside, the river becomes channelized to protect the higher-density residential areas from flooding, becoming natural again only near the estuary. Much of the channelized portion is dry except during large rain events.

About 8 percent of the City of Oceanside’s drinking water supply comes from the SLR Valley Groundwater Basin. Water from the basin is pumped from wells and treated at a reverse osmosis plant before being distributed to Oceanside residents.

The estuarine section of the river has slight meanders and a natural bottom and terminates in a lagoon most times of the year. The river empties onto Oceanside Harbor Beach, separated from the harbor facilities on the north side by a levee and jetty extending into the ocean. To the south of the river outlet are a cluster of vacation accommodations and beach homes. These buildings extend all the way to the water, bisecting the beach via a strip of shoreline protection and forcing the river outlet into a small section of beach between the jetty and the homes.

The estuary is currently crossed by Interstate 5 and a railroad bridge. A small paved road formerly covered the estuary at the beach, only allowing flow through a small culvert. This road has now been moved slightly inland and elevated above the water surface to allow more normal flows to the ocean.

Wetland Expansion Potential

Wetland Migration

There is some limited potential for wetland expansion within the river valley, but no potential acquisitions.

Constraints on Expansion

The primary constraint is topography. The river valley is fairly narrow, and what little floodplain exists is heavily developed.

Public Access


The mouth of the river is easily accessible where the SLR River enters the Pacific Ocean.

Recreational activities in the estuary include fishing, swimming, walking, biking, and bird watching.


The San Luis Rey River Trail runs from Neptune Way and N. Cleveland St. to Highway 76 at N Santa Fe Ave. For most of its 9-mile length, it runs along the river. At the eastern end, it connects to an extensive trail network in Guajome Regional Park. The trail is paved, mostly flat, and suitable for biking or walking.


The west end of the River Trail is about 3/4 mile from the Oceanside Transit Center served by Amtrak, Metrolink, Coaster, and Sprinter trains as well as a number of bus routes.

There are several 311 bus stops near the midpoint of the trail. The 311 bus connects with the Sprinter at Rancho Del Oro.

The eastern trailhead is a short walk from a 303 bus stop at N Santa Fe Ave & Alamosa Park Dr. The 303 bus connects to the Coaster and Sprinter at the Oceanside Transit Center and to the Sprinter at the Vista Transit Center. This makes it possible to hike the trail one way and return by bus.


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