Permanent solution for silt

Having read and heard quite a bit about dredging the accumulated silt in Mirror Pond, I have come up with the perfect solution to the problem.

A few things need to be understood by all. These include the facts that the residents of Bend will never permit this iconic piece of Bend to become a swampy marshland, that the silt has accumulated slowly over a period of decades, that the silt that has accumulated in Mirror Pond is just silt and not toxic waste, and that dredging the silt in one large operation is too expensive and would be opposed by some people with lawyers.

My solution, the perfect solution, is to install a very small-scale dredging apparatus on the south side of the Greenwood Avenue bridge that would be capable of removing the silt at twice the rate that the silt is accumulating and that could be moved around the area of deepest silt accumulation. This apparatus could be completed submerged and not visible, except to fish, frogs and ducks.

A relatively small pipeline — probably not more than a few inches in diameter, but that would have to be determined by a competent engineer — could run from the dredger intake to one of three or more places. The pipeline could simply run around the Pacific Power dam at the Greenwood Avenue bridge, further down the river past the next diversion dam; or to some downstream parcel of land onto which the dredged silt could be temporarily deposited.

The problem of merely moving the silt around the Pacific Power dam is that the silt would accumulate at the next downstream diversion dam. That just moves the problem from Mirror Pond to the next diversion dam. Although it is a fact that all dams get silt behind them over time, nobody wants their dam to “silt up.”

Making the pipeline long enough to get around that next diversion dam would be more expensive and would only move the silt further downstream to the next diversion dam.

Depositing the dredged silt on a downstream parcel of land is also not going to be cheap, but the silt may have some value to farmers, home gardeners or to local landscaping companies for topsoil — ever try to grow something in a lava bed like the ground in much of Bend? That might provide some revenue for this project.

This mini-dredge could be run at full capacity for a number of years (perhaps with some project power from the Pacific Power dam) until enough silt was removed to assure the continued existence of Mirror Pond in an acceptable state and then run at a rate that moves newly accumulated silt out of Mirror Pond.

Lots of Bend citizens would get behind this project financially, including me, which may help to get this project funded. I’m certain that the city, the Bend Park & Recreation District and Pacific Power would love to have a simple, cheap and elegant solution to this problem and would be able to find some funding for it. This plan has the advantage of being a long-term solution to the problem of accumulation of silt behind the Pacific Power dam, rather than a near-term fix — like a huge dredging project — that would have to be done again in a few decades.

I await your congratulations and the appreciation of the citizens of Bend!

— Dennis Sienko lives in Bend.

Source: The Bulletin: Permanent solution for silt

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