Our Power Boats & Water Clarity

A location near Divine Word clearly shows prop damage to the lake bottom. Dark streaks in deeper water which may not be visible here also indicate boat propeller damage.

Boats and boat activity are an important issue with regard to Lake Beulah’s aquatic ecosystem. The last 100 years have seen a tremendous increase in the number of motor boats on Lake Beulah. Not only are there more boats, but they are larger and with bigger engines than ever.

Given that boats and boating are such a huge part of our enjoyment of the lake, it behooves us to keep in mind our pleasure doesn’t come without impact. One of those impacts is on Lake Beulah’s ‘water clarity’. Impacted by the amount of particles in water, water clarity is a measure of the degree to which light can travel through water. An important measure of ecosystem health, water clarity impacts Lake Beulah in a variety of ways;

• Ability of fish to find food

• Depth to which aquatic plants can grow

• Amount of dissolved oxygen in the water

• Water temperature

Boating activity can affect water clarity.

• Propellers may disturb the lake bottom either directly, or through the turbulence generated, particularly in shallow water. This ‘stirring action’ increases the amount of suspended sediment, while also raising nutrients stored in the sediment making them available for growth of undesirable algae.

• Waves created by watercraft can also contribute to shoreline erosion, thereby bringing more particles that cloud the water.

Those of us who are fortunate enough to be out on the water during the week are certain to notice how different the water looks on Fridays compared with Sunday afternoons.

As power boaters, what can/should we do to help Lake Beulah’s water clarity?

• Use particular care in slow-no-wake areas

• Keep your motor trimmed up and keep speed low in waters less than 10’ deep. You might want to occasionally check behind your boat to see if you’re stirring up the bottom.

EDITORS NOTE: This article is first in a seven-part series that will help readers understand the impact of motorized boats on Lake Beulah. Most information comes from the Wisconsin Department of Natural Resources (PUBL-SS-948-00)