Beach · Jefferson County · WA
Is Se Dabob Bay safe to swim?
Recent heavy rain may have spiked bacteria since the last clear sample.
Updated July 19, 2026 · Washington beach program (EPA BEACON)
SwimZone for iPhone · launching soon
Know before you get in at Se Dabob Bay.
Get an alert the day a bacteria or algae advisory goes up.
What's in the water at Se Dabob Bay right now
As of July 19, 2026, Se Dabob Bay in Jefferson County, Washington carries a swim caution. Blue-green algae are not currently monitored at this water. No fecal-bacteria advisory is posted (state beach program). Rainfall over the past week totaled 1.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Se Dabob Bay
Se Dabob Bay is a lake in Jefferson County, Washington. Blue-green algae are not currently monitored at this water.
Blue-green algae (cyanobacteria) blooms are most common from midsummer into early fall, when the water is warm, calm, and rich in nutrients from runoff. They can produce toxins that make people sick and can be rapidly fatal to dogs, so skip water that looks green, scummy, or like spilled paint, and keep children and pets out of it.
Frequently asked: swimming in Se Dabob Bay
- Is it safe to swim in Se Dabob Bay right now?
- Se Dabob Bay carries a swim caution today. Blue-green algae are not currently monitored at this water. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does Se Dabob Bay have blue-green algae (cyanobacteria)?
- Blue-green algae are not currently monitored at Se Dabob Bay. Watch for green, blue-green, or paint-like scum and avoid the water if you see it.
- Can dogs swim in Se Dabob Bay?
- No bloom is detected at Se Dabob Bay today, but dogs are much more vulnerable to blue-green algae than people, and blooms can form within hours. Always keep dogs away from water that looks green, scummy, or discolored, and rinse them off after swimming.
- How many Washington lakes and beaches have swim advisories today?
- Today, 18 Washington waters are under a swim advisory and 9 more warrant caution, out of 1348 monitored waters SwimZone tracks in the state.
- How is Se Dabob Bay's water quality measured?
- SwimZone builds this read from EPA CyAN satellite imagery for blue-green algae, official beach and fecal-bacteria advisories where a program monitors Se Dabob Bay, and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.