Despite the beach-friendly weather this week, it's been tough to find a place to go for a dip in Windsor-Essex.

Signs warning swimmers of the amount of E. coli and other bacteria in the water have been posted at several beaches in the area.

Mike Tudor, manager of the health inspection department at the Windsor-Essex County Health Unit, says one possible cause of the high bacteria levels is the recent heavy rains we've had. 

"Basically, it flushes all the storm drains, as well as rivers, and just causes turbulence of the beach conditions; causes the water to become more turbid, lifting any of the sediments off the bottom and potentially causing this adverse count," he said.

Recent warnings are based on samples that were collected a week ago.

The health unit collects five new samples from each of 10 beaches every Wednesday.

Two inspectors travel 200 km a week collecting water samples.

So far this year, at least one beach has been closed every week because there's too much E. coli bacteria in the water.

Windsor's Sandpoint Beach has been closed more than it's been open this year. And on the Canada Day weekend, more than half the beaches were closed. The other beaches had warnings posted at them.

Chitra Gowda, a water quality analyst with the Essex Region Conservation Authority, says more intense and shorter duration rainfalls are partially to blame.

"With larger rainfalls ... they run off a lot of bacteria and pollution off the land and into the Great Lakes," she said.

E. coli and other bacteria comes from older sewage systems overflow, geese and other animals, industrial runoff and pollution and runoff from farms.

"The only thing I can pinpoint is the weather conditions. There are various things that affect the adverse counts," Tudor said.

Bacterial counts reflect the conditions at the time of sampling. But conditions change from day to day depending on the weather conditions and lake levels.

However, Tudor said it's cost prohibitive to sample every day.

When a beach is closed, the public must be notified.

"The operator of the beach is supposed to post it at the various entries as well as put up some physical barriers … at the main entries," Tudor said.

There are some things the public and beach operators can do to curb rising E. coli levels.

Gowda said residents can build rain gardens, for example.

Beach operators can employ bird avoidance measures, such as wires over the water that prevent birds from landing. Hamilton and Toronto use them.

In Leamington, Seacliffe Beach uses a storm water management system that takes storm water from parking lots and drains it away from the beach.