San Diego Bay TMDL Modeling
A Total Maximum Daily Load (TMDL) study is conducted for three estuary mouths
in San Diego Bay that receive freshwater and particle-bound contaminant loads
from the surrounding watersheds via three creeks: Chollas, Paleta and Switzer.
These three estuary mouths are on the State of California’s 303(d) list
of impaired waterbodies, which requires a TMDL study on total suspended solids
metals, polynuclear aromatic hydrocarbons (PAHs), and chlorinated hydrocarbons
(CHCs) in the estuary mouths.
For this study, joint efforts have been initiated
by both Southern California Coastal Water Research Project (SCCWRP), Regional
Water Quality Control Board (RWQCB)-San Diego, and Spawar Systems Center,
San Diego (SSC Pacific). An integrated model is being developed that links
watershed model with a fate and transport model for the receiving Bay water.
contaminant loads, along with the freshwater inflows, are simulated using
LSPC, which is an EPA-approved watershed model. The model is set up at scales
can resolve both spatial and temporal variabilities, both dry and wet seasons
will be simulated. The LSPC predicted freshwater inflows and contaminant
loads at the mouths of the three creeks are linked to the CH3D model which
the hydrodynamics and fate and transport of these contaminants in San Diego
Capabilities (direct support):
- TMDL Modeling
- Model for TMDL study
- Simulation for designed load reduction scenarios
- Provide particulate loading source for long-term fate/transport in sediment
The integrated watershed (LSPC, left figure) and fate/transport (CH3D,
right figure) model for TMDL at the mouths of three creeks, including Switzer,
Chollas and Palate Creeks in San Diego Bay.