The Ecology of Tijuana Estuary, California: An Estuarine Profile

The nearby bridge remained, and extensive
disturbance by vehicle traffic had occurred.
By 1970 several new disturbances were visible.
Additional apartments had been built along the
coast, and the barrier dune no longer supported
good vegetative cover. Large areas of dune
washover had developed both north and south of
the estuary mouth. As is obvious from events of
the 1980's, this relatively gradual loss of dune
vegetation ultimately had an estuary-wide impact.
The sewage operation at the inland lagoons had
been abandoned, and saline pannes were obvious
dur~ng the July, dry-season photo. Tidal flushing
was lacking behind the diked areas. The mouth
had shifted southward. East of the sewage
impoundments, a channel had been dug to direct
street runoff into the southernmost lagoon.
In January and again in February of 1980,
floods that exceeded ail previous flow records
simultaneously eroded and filled different parts of
the estuary. The flooding shifted the course of the
Tijuana River from its southern channel (Figure 1 1)
across several parcels of agricultural land, carving
a diagonal channel toward the airport, where it
connected with the central estuarine channel. A
much broader coastal embayment was created at
the river mouth. Major sedimentation occurred in
the southern half of the estuary. Monument Road
was buried by half a meter of silt that flowed down
Goat Canyon.
In January 1983, concurrent high tides and
heavy surf flooded Sea Coast Drive and washed
sand between the apartment buildings into the
street and onto the edge of the salt marsh. Where
Figure 11. The February 18, 4 978, aeriaf photograph of Tijuana Estuary (from Aerial Fotobank). Note development
on beach (51, abandoned sewage oxidation ponds (S), gravel excavation (61, agriculture (A), and location af main
river channel (Rl.