3.2 Coastal Wetlands
dredging the entire lagoon was completed in January 1997, which allowed sustained tidal flushing of the
lagoon. Prior to the enhancement project, the lagoon consisted of 550 acres of shallow wetland, which
included estuarine open water, southern coastal salt marsh, and tidal estuarine flats. The lagoon area
supported a number of nesting migratory birds, including the California least terns and western snowy
plovers. The lagoon had been subject to frequent inlet closures due to the buildup of a sand and cobble
berm. The lagoon closures led to a substantial accumulation of organics and fine anaerobic sediments,
persistent eutrophic conditions (i.e., enriched in dissolved nutrients that stimulate the growth of aquatic plant
life resulting in the depletion of dissolved oxygen), development of algal mats, and wide swings in salinity.
Since the completion of the enhancement project, habitat throughout the lagoon has been altered. The
primary habitat is estuarine open water followed by coastal salt marsh. Nesting islands support endangered
R
California least terns and threatened western snowy plover. The lagoon also functions as habitat for marine
R
and estuarine species of invertebrates and fish.
R
The new ocean inlet to the lagoon is protected by two jetties that enable sustained tidal flushing. Due to
the dynamics of the lagoon, the west and central basins are expected to naturally accumulate beach sand
and will require routine maintenance dredging similar to that conducted at Aqua Hedionda Lagoon every
two years.
San Elijo Lagoon
The inlet to San Elijo Lagoon is located north of the proposed Cardiff receiver site. San Elijo Lagoon is
comprised of approximately 900 acres and includes the 590-acre San Elijo Ecological Reserve, which is
managed by the CDFG and the San Diego County Department of Parks and Recreation. It is rarely open
to tidal flushing due to its relatively small tidal prism and frequent blockage by a substantial volume of
cobbles. Experimental excavation of the inlet area and high stormwater runoff events have resulted in
periodic opening of the lagoon to tidal flushing for short durations spanning a couple to several months.
Most of the habitat consists ofbrackish/freshwater marsh, nontidal flats, and open water. San Elijo Lagoon
is one of the highest ranked waterfowl habitats among the coastal lagoons in San Diego County because
of its diverse habitat and shallow brackish water. Both the endangered Belding's savannah sparrow and
California least tern nest at the lagoon. California brown pelicans use the open water to rest and feed.
Regional Beach Sand Project EIR/EA
Page 3.2-3
99-69\SANDAG EIREA 3.4.wpd 7/17/00
Previous Page
