Beach · Sussex County · DE
Is Deauville Beach (Cape Henlopen State Park) safe to swim?
No advisory or algae bloom reported for this water today.
Updated July 19, 2026 · Delaware beach program (EPA BEACON)
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What's in the water at Deauville Beach (Cape Henlopen State Park) right now
As of July 19, 2026, Deauville Beach (Cape Henlopen State Park) in Sussex County, Delaware is clear to swim. 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 0.0 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Deauville Beach (Cape Henlopen State Park)
Deauville Beach (Cape Henlopen State Park) is a lake in Sussex County, Delaware. 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 Deauville Beach (Cape Henlopen State Park)
- Is it safe to swim in Deauville Beach (Cape Henlopen State Park) right now?
- Deauville Beach (Cape Henlopen State Park) is clear to swim 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 Deauville Beach (Cape Henlopen State Park) have blue-green algae (cyanobacteria)?
- Blue-green algae are not currently monitored at Deauville Beach (Cape Henlopen State Park). Watch for green, blue-green, or paint-like scum and avoid the water if you see it.
- Can dogs swim in Deauville Beach (Cape Henlopen State Park)?
- No bloom is detected at Deauville Beach (Cape Henlopen State Park) 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 Delaware lakes and beaches have swim advisories today?
- Today, none of the 22 monitored Delaware waters SwimZone tracks are under a swim advisory.
- How is Deauville Beach (Cape Henlopen State Park)'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 Deauville Beach (Cape Henlopen State Park), and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.