Environmental Tools
SWPPP & STORMWATER SUPPORT
Receiving Water Finder
CALIFORNIA · NHD TRACE · 2024 INTEGRATED REPORT
Enter a project address to find where site runoff ends up — the named waters it passes through,
the terminal receiving water, and each one’s 303(d) listing status. For a site you know,
dropping a pin on the actual point of discharge gives a far better answer than the street address.
Or paste coordinates as
latitude, longitude — e.g. 37.970072, -122.045823
Drag the marker to the point of discharge, then re-trace.
Stormwater Compliance Assistant
CGP 2022-0057-DWQ · MRP 3 PROVISION C.3 & C.6 · CCCWP C.3 GUIDEBOOK 9TH ED. · ACCWP C.3 TECHNICAL GUIDANCE 8.4
Ask a SWPPP, risk-level, sampling, C.3 threshold, LID sizing, or hydromodification question and
get an answer drawn only from the loaded permit text and the Contra Costa or Alameda C.3 guidance, cited by
section and printed page. Design questions come back in two labelled parts — what the
documents require, and a worked example from your inputs — so the two are never confused.
Open the assistant
What this tool does not tell you. It does not know the storm drain network — no statewide
dataset of municipal storm sewers exists — so the first receiving water is offered as
candidates to check against the local storm drain map, not as a settled answer. The
terminal water is reliable: whatever route the pipe takes, runoff ends up in the same place.
It does not determine Clean Water Act jurisdiction. Whether a water is a “water of the United States” is a case-by-case determination made by the Army Corps of Engineers, and there is no map that answers it — EPA publishes its own only “for informational purposes.” Nothing shown here should be read as a jurisdictional call, and an unflagged water is not thereby non-jurisdictional.
Sources: USGS NHDPlus and the Network-Linked Data Index for the trace; California State Water Resources Control Board 2024 Integrated Report for waterbody names and 303(d) status. Always confirm against the current SMARTS receiving water list before filing.
It does not determine Clean Water Act jurisdiction. Whether a water is a “water of the United States” is a case-by-case determination made by the Army Corps of Engineers, and there is no map that answers it — EPA publishes its own only “for informational purposes.” Nothing shown here should be read as a jurisdictional call, and an unflagged water is not thereby non-jurisdictional.
Sources: USGS NHDPlus and the Network-Linked Data Index for the trace; California State Water Resources Control Board 2024 Integrated Report for waterbody names and 303(d) status. Always confirm against the current SMARTS receiving water list before filing.