Freedom – July 12, 2008 – Not much of interest to report regarding storms and the lake level. Since early June only a few storms have added water to the lake because most of them were south or north of Ossipee and moved through rapidly.
Two weeks ago on Sunday, June 29th we had the most recent storm affecting lake level. It was predicted and did dump lots of water, but only on a small amount of area that drains into the lake. The Bearcamp River reported less than .3″ that drained off in less than a day. Ossipee Lake reported more than 2″ in the same time period. The big lake received all of this rain and a layer of hail. Here on Broad Bay we had the rain but no hail.
Net result was a series of quick responses by the Dam Authority:
Friday, June 27 — The dam was closed because water level was 7.25 and going down
Sunday, June 29 — Flow over the dam increased
Monday, June 30 — Dam opened to triple water flow
Tuesday, July 1 — More gates opened to increase flow by another 200 cubic feet per second
Thursday, July — Partial dam closure that decreased flow by 400 cfs
Saturday, July 5 — More gates closed and flow returned to the June 27th rate of 254 cfs
Yes, the level got up to 7.7 for a few days but it got back to 7.25 in less than five days thanks to four working visits to the dam by state and local authorities. Just to complicate things, the nearly new electronic gauge failed on June 30 and Concord has been relying on manual data to track the water level and make decisions on opening and closing the dam. Also keep in mind that the actual opening and closing is a manual effort by a few people on a part-time basis.
There is a proposal by the state dam authority to renovate the north side gates and install electronic operating equipment that will open and close the gates with the push of a button in Concord where the decisions are made. The only hold up is funding.
Boat traffic has been very light so far this year. Weather was good for the 4th and activity picked up. There was good coverage on Broad Bay by the Marine Patrol. Last Sunday we counted 13 bass boats going out at 7 am. They got hit with a storm about 2 pm. Weather was good on the 2nd for the Huckins fireworks and on the 4th for Ossipee. We counted 85 boats going north in front of our place on Broad Bay after the fireworks.
I visited with Tim at the marina this morning. Water level has been friendly to the operation. Boating activity is equal or greater than last year but people tend to go out for the day. There is less zoom/zoom action.
Just a reminder – everyone operating a boat with more than 25 HP needs a state Safe Boating Certificate. Us old timers can no longer get by on age. Also – it is legal to launch a water skier from a dock or beach but on the return trip you must drop to “No Wake Speed” 150′ from a dock or the shore.
The dam authority has done a great job this year, but I’m wondering if keeping the lake high is contributing to erosion, and whether erosion is filling in the lake making it necessary to make the lake higher. There is a connection here that I don’t think people are looking at. Anyone else have the same feeling?
Response to comment: I’m seeing bottom texture variation. It’s like a blanket of bottom sand repositions with the changing prevailing bay currents. Some seasons the blanket moves off and we walk on a gravely bottom other years that gravel is buried by sand.
I can’t verify the fact but I’m thinking slower high water eddies the sand in and a lower lake level lets the current of the submerged Ossipee River draws the sand out.
If they rework the dam… a gate configuration that periodically flushes some of the rich bottom sentiments down stream might better mimic the more historic river lifecycle.
I’d think they could monitor the lake bottom contours to determine a rate of change and find the dominate fill collection locations . There’s likely some commercial break even value for all that sentiment & sand fill should conditions someday warrant remedial “lake bottom” landscaping.
Certainly dam managment’s cause & effect dynamics on the overall eco-system could be better understood.
Don MacLeod