Is it safe to swim at Imperial Beach?
Often not: the Imperial Beach shoreline was closed again on September 28, 2026 because sewage-contaminated Tijuana River water was reaching the ocean — check sdbeachinfo.com the day you go, and expect more closures in an El Niño winter because rain overwhelms treatment capacity.
- Status Sept 28, 2026
- Closed (IB shoreline)
- Check before you go
- sdbeachinfo.com
- 24-hr hotline
- (619) 338-2073
- Longest recent closure
- 1,000+ days
The short version
- As of Sept 28, 2026, the County closed the Imperial Beach shoreline to water contact; Tijuana Slough and Border Field also remained closed.
- Closures are issued by the County Department of Environmental Health and Quality and stay in place until sampling shows the water meets state standards.
- Parts of Imperial Beach were closed for more than 1,000 consecutive days before most of the shoreline reopened in September 2024.
- Rain increases the river's flow and can overwhelm sewage treatment capacity — a real concern for a wet El Niño winter (CalMatters).
- Fixes are underway: the U.S. plant expanded to 35 million gallons a day in August 2025, with river diversion gates due by January 2027.
Imperial Beach is a great beach town with a pier, a long flat beach and some of the most consistent surf in the county. It also sits just north of the Tijuana River mouth, and the river carries untreated sewage and industrial runoff from across the border. The result: the water is closed to swimming a lot of the time, and whether it's open today depends on the river, the swell and the rain.
South Bay shoreline, border to Coronado
Closure status from County DEHQ announcements, Aug 23 and Sept 28, 2026. Status changes day to day — check sdbeachinfo.com.
Closure vs. advisory — they're different
What the County's signs mean
| Closure | Advisory | General rain advisory | |
|---|---|---|---|
| Why | Known sewage reaching the water | Bacteria sampled above state standards | Rain washes runoff into all coastal waters |
| Swim? | No — water contact prohibited | Not recommended — risk of illness | Avoid for 72 hours after rain, countywide |
| Ends when | Sampling and field checks confirm it's safe | Follow-up samples meet standards | 72 hours after rain stops |
| Verdict | Stay out | — | — |
Why El Niño makes it worse
When it rains, the Tijuana River's flow jumps, and the added volume can exceed what treatment plants on both sides of the border can handle — sending more untreated waste down the river and out to sea. CalMatters reported in August that residents of south San Diego and Imperial Beach "routinely confront sewage and industrial contamination from the Tijuana River," and that heavy rain makes it worse. A wet winter means more days like September 28.
1,000+
Consecutive days parts of IB were closed before Sept 2024
35 MGD
U.S. South Bay plant capacity after Aug 28, 2025 expansion
50 MGD
Next expansion target, in early work (EPA)
The fixes, and when they're due
EPA Tijuana River Watershed public updates (June 2026). Dates are agency targets.
- 01
Check the day you go
sdbeachinfo.com shows closures and advisories on a map; the 24-hour line is (619) 338-2073.
- 02
If it's closed, head north
Coronado Central Beach is 15 minutes away — but check it too, since plumes sometimes reach it.
- 03
Skip the water for 72 hours after rain
That's the County's standing advice everywhere, not just in the South Bay.
- 04
Enjoy the town anyway
The pier, the beach walk and Seacoast Drive are open even when the water isn't.
KEEP READING
SOURCES
Everything above traces back to one of these. Follow them — if one has changed and we haven't, that's our mistake, not yours.
KPBS (quoting County DEHQ) · 2026-09-28
Closure statement; Tijuana Slough and Border Field closed; hotline
County of San Diego, Department of Environmental Health and Quality · 2026-09-29
Official closure and advisory map
U.S. Environmental Protection Agency · 2026-06
35 MGD completed Aug 28, 2025; gates, effluent relocation, 50 MGD
Times of San Diego · 2026-08-23
Closed segments; Avenida Lunar advisory
KPBS · 2024-09-23
1,000+ consecutive days
CalMatters · 2026-08-01