What happens if we don’t dredge?

The waterway will continue to fill in and become impassable. The question is, how long will that take?

It is possible to estimate this, based on past history of how many years it took to fill our impoundment to the present level of silt, and also on some more recent direct measurements. This was done by Dr. Andres Peekna (Innovative Mechanics, Inc., currently a WWMD Commissioner).

We are at a tipping-point now. In many areas, the depth of water above the muck is down to 2 feet, and in some, just 1.5 feet. In about 10 years, the muck levels would be about 5-6 inches higher. Many power-boats would no longer be able to operate in many areas.

In about 20 years, the muck levels would be close to a foot higher. Except in Tichigan Lake, forget almost all power-boats, except perhaps shallow-draft boats equipped with air-cooled “Go-Devil” motors. Human-powered boats (pedal-driven paddle-wheel boats, canoes and kayaks) will survive, though their use too will be hampered.

A direct check on the short-term fill-in rate in bays was recently performed by Andres and Susan Peekna. This was based on baseline data taken in 2010 at four shoreline sites, two in Island View Bay and two in Buena Lake. This year, new data were taken at these same sites. The results are consistent with estimates based on more long-term past history. Using different methods makes the results more credible.