Prediction of Beach Water Quality

The best way to protect the health of you and your family when using the beaches is to make an informed decision before bathing. The Health Units regular samples are a good way to monitor the beaches for bacteria. However, due to the delay in receiving lab results and the frequency of testing this monitoring only forms part of your decision making process. The information below will help you predict the quality of beach water during your visit.

Rain

Rain is the single biggest factor to impact on beach water quality. Rain washes contaminants into streams, rivers and lakes. Whilst small amounts of rainfall are unlikely to have much impact, the Grey Bruce health unit advises bathers to avoid bathing for at least 24 hours after heavy rains. If the rainfall has been heavy for several days causing saturated ground and higher water levels in streams, rivers and drains the recommendation is to avoiding bathing for at least 48 hours.

Wind

Wind can quickly build up significant waves. Wave action on any body of water can stir up sand and silt making the water cloudy (see below). The Grey Bruce health unit advises bathers to avoid bathing until waves have reduced to a reasonable level, and water is no longer cloudy.

Turbidity (cloudiness)

Cloudy or turbid water is more likely to contain higher levels of bacteria. Cloudy water is often caused by heavy rain fall or large waves. Whatever the source the Grey Bruce Health Unit advises bathers to avoid bathing unless the water is clear. As a rough guide, you should be able to see your feet at 1 meter depth of water (adult’s waste depth).

Waterfowl (seagulls, geese etc.)

In some smaller bodies of water, or more confined areas of large lakes, waterfowl can have a significant impact on water quality. The Grey Bruce Health Unit advises bathers to avoid bathing in confined bodies of water with significant numbers of waterfowl.

Other Factors

Shallow bodies of water are likely to be warmer than deeper ones during the summer. Warm temperatures are more favourable for bacterial survival or growth. In clear water bacteria in suspension will be killed quite quickly by sunlight, although they may still survive in silt and sand.

The Grey Bruce Health Unit only samples at a number of locations. We do not sample at all beaches or bodies of water that may be used for recreational purposes. It should be noted that these sites may also be unsafe for bathing at times. Although we cannot provide supporting data for other locations, much of the information provided above will still have some relevance.

If you would like to see the sample results, follow these links.

Recent beach samples

Historic beach samples (coming soon...)

Weather forecast

Blue Flag Beaches

Four beaches in Grey and Bruce Counties hold the Blue Flag designation: Sauble Beach (South Bruce Peninsula); Station Park (Kincardine); Little River Park (Blue Mountains) and Northwinds (Blue Mountains). For more information on Blue Flag visit www.blueflag.ca