Monday, February 23, 2015

More Dam News

There are a couple of articles on the Conowingo Dam issue that's been plaguing the Bay for, literally, as long as I've been here:

Capacity report holds no surprises for Conowingo Dam
A study released by the U.S. Geological Survey echoes much of what has already been found of the Susquehanna River and its relationship to the Chesapeake Bay.

The 28-page report authored by Michael Langland shows the storage capacity for sediment behind the Conowingo Dam has reached its saturation point.

“The Conowingo Reservoir is at — or very near — filled to capacity,” Langland said Thursday.

As dire as it sounds, Langland said the situation is not an emergency.

“It doesn’t mean that the dam is filled to the top,” he said. “It means the capacity to trap is nearly extinguished.”

A study released in November by the U.S. Army Corps of Engineers concluded that, while there is an enormous sediment build-up, it is the content carried by the sediment that is the greater threat to the health of the bay.

Langland said the USGS report “is an expression of the (Corps of Engineers) report.” He added no decisions are made in either document.

“That has to be debated and decided by the people with the purse strings,” Langland said.
Watching this develop has been like watching the Titanic approach the iceberg, only slower. When I arrived in Maryland in 1985, it was commonly acknowledged that the pool behind Conowingo Dam was filling, and it was only a matter of time before it lost it's ability to retain sediments. In fact, I think they said 20 years. So the time is here, and nothing has been done.

So what to do? I know! Let's order another study! That'll put it off another couple of years.

UM scientists launch new Conowingo pollution study
Expected to take two years, the new study announced this week by the University of Maryland Center for Environmental Science comes on the heels of a joint federal and state assessment that the sediment buildup behind the dam is playing a relatively small but still significant role in degrading the upper bay.

That review, which took three years, concluded that dredging enough silt from behind the dam to restore its pollution-trapping capacity would cost up to $3 billion, and would provide only modest and temporary help.

A coalition of mostly rural counties, though, has argued that dredging would do more to help the bay than other costly and unpopular cleanup measures communities are being required to carry out, such as curbing storm-water runoff and dealing with pollution from household septic systems.
Here's my take on this mess. Conowingo Dam has been providing an accidental service to the Chesapeake Bay since it erected in the 1920, stopping sediment from the Susquehanna from entering the Bay.

Dredging behind the dam is expensive, approximately $3 billion (with a "b"), and the costs are likely to be borne by the states and feds.  The other way to get the amount of nutrient reduction from the Chesapeake Bay required to make the "Bay Diet" restrictions is to force the farmers to make expensive changes in how and when they fertilize.

So, given that you have the power to decide who has to pay, do you pay it yourself, or make the other guy (agriculture) ante up? The question practically answers itself.

In the grand scheme of the "Bay Diet" $3 billion is relatively small; the government share of the Bay Diet is expected to be $25 billion, and rising in accordance to Cheops' Law.

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