Lake Draw down

[20mile]

I heard a rumor that they are going to draw the lake down 5-15 feet in October to allow for crib dock repairs, water lines and other dock repairs. I have never seen this happen before. Is this just an exaggerated story or is there truth to it?

[Lakegeezer]

Originally Posted by 20mile

I heard a rumor that they are going to draw the lake down 5-15 feet in October to allow for crib dock repairs, water lines and other dock repairs. I have never seen this happen before. Is this just an exaggerated story or is there truth to it?

Check out http://www.des.state.nh.us/press/arc...ss09042007.htm It is the state's 2007 drawdown press release from early September. They don't list Winnipesaukee, but discuss how it will likely end up 2' below full lake level.

[newbie]

....Not included in this schedule is Lake Winnipesaukee. Unlike the other lakes in this schedule, Lake Winnipesaukee is not purposely drawn down in the fall. Instead, each year on Columbus Day, the releases from Lakeport Dam are reduced from a normal minimum of 250 cubic feet per second (cfs) to a flow between 30 and 50 cfs for a period of up to two weeks to allow for maintenance of the dams and hydropower facilities on the Winnipesaukee River. The flow of 30 to 50 cfs is the minimum flow needed to maintain the downstream aquatic life during this period.

By the middle of the fall, Lake Winnipesaukee is, on average, 15 inches below its springtime full level due to evaporation and releases from the lake that have occurred over the course of the summer. As a result of the reduction in the amount of water released from the dam after Columbus Day, the lake level does not drop for the remainder of the month of October and is generally maintained at this level through the month of December. Depending on the amount of snow on the ground in the winter, the lake level may be lowered further beginning in January to a depth of two feet below the normal full level.

A plot of the average lake levels throughout the year for Lake Winnipesaukee is provided on DES’s website at http://www.des.state.nh.us/dam/graph.htm. Also included are updated plots of this year’s lake levels, releases from the dam, and precipitation.

[Rattlesnake Guy]

Gal and I were at the Belknap Mill on Saturday. (A very interesting piece of history in Laconia) We noticed that the water was barely flowing past the mill. We went up up to the Lakeport dam and as you would expect, it was barley moving as well. Most of what was happening seemed to be going through the turbine building.

[Rattlesnake Gal]

Sorry I didn't get the shot of it flowing from the power plant.

[Sal]

I noticed on the lake level site, that the level dropped 6 " and then returned to where it was, within an hour or so (http://www.des.state.nh.us/rti_inter...+Winnipesaukee)

How the heck did THAT happen?

[chipj29]

Originally Posted by Sal

I noticed on the lake level site, that the level dropped 6 " and then returned to where it was, within an hour or so (http://www.des.state.nh.us/rti_inter...+Winnipesaukee)

How the heck did THAT happen?

There was some discussion about that in this thread, starting around post #36.
http://www.winnipesaukee.com/forums/...ead.php?t=5117

[HomeWood]

How do you think the level will be next week? 1st to the 7th?

[Weirs guy]

Originally Posted by HomeWood

How do you think the level will be next week? 1st to the 7th?

Leave your boat on the trailor and drive it around where you want to fish. No, really. Its that low.

[HomeWood]

Originally Posted by Weirs guy

Leave your boat on the trailor and drive it around where you want to fish. No, really. Its that low.

C'mon?? Can't be that bad.

[This'nThat]

Originally Posted by HomeWood

C'mon?? Can't be that bad.

According to this, the lake is 1.5 feet below full, as of 28 September. This is not a record low; however, it is 1 standard deviation below average for this time of the year. That means that this level is reached once every 6 years or so, or about 3 times over the last 20 years.

[Irish mist]

We need some soaking rain.......soon. Too dry out there.
________
VAPORIZER REVIEW

[HomeWood]

I went boating here a month ago and the lake was down about 4.5 feet, about 5.5 now and it was fine for my type of boat. 1.5 feet below normal is fine with me. I can float in one foot with the trim up. Thanks for the tip. I'll be up tomorrow.

[Weirs guy]

OK, you don't need a trailor, just a shovel to get thru the channel. The mooring at the end of our beach is usually 2 foot over my head, but today if you'd like I can walk out and hand it to you at about chin depth.

[SIKSUKR]

I checked the lake level on the channel bridge Wed the 26th and it was exactly 18 inches down from full lake.

[macshpman]

Wondering what the lake level currently is at this time. Been holding off on the winterization and hoping to boat one last time before the end of the month.

[Grant]

The latest from Bizer's table:

10/04 Thu 2.78 - .40 65 248 CFS
10/11 Thu 2.84 - .26 65 36 CFS
10/18 Thu 2.81 - .37 58 34 CFS

Flow from dam is down to a fine trickle. Any less, and the river will be flowing back into the Lake.

Current levels found here.

Running DES chart found here.

[macshpman]

Thanks Grant Looks like Monday may be a decent day. May have to close shop and head to the lake. Yahooooooooooo.

[Weirs guy]

Remember, the rivers are at a trickle for down stream damn maintenance (Lakeport Damn is closed). Here in Franklin you can walk across the river and get a toe wet, maybe.

In a week or so when there done the stopper comes back out!

[Smith Point]

I would like to know when the people who control the dam will be drawing down the lake?

It is my understanding that the lake is drawn down once every 10 years. But I can’t remember the last time this happened. I can remember walking from our boat house to the dock as a kid (4 feet below normal) so people could work on their crib works, shore line, boat houses, etc.

So can anyone tell me when they plan to do it?

So we as lake front property owners (who pay a premium for our properties) can pull permits in advance to work on our properties

[kchace]

I highly doubt this will be happening anytime soon. A drawdown of that magnitude would have significant impact in many areas. For example, the Weirs Channel is only about 5' deep in many spots so it would be essentially dry. I imagine there would be negative environmental impacts as well.

I've been coming to the lake more than 20 years and have never heard of or seen a drawdown any greater than the normal 'low' winter levels we've been seeing. The data on Bizer's lake level page shows data from 1984-2007 and it is clear it has not happened during that timeframe.

Ken

[Smith Point]

Ken, I’m telling you that this was a long time ago, in the early 70s
The question still remains, do they draw down the lake every 10 Years? For shore line repairs?

[Blue Thunder]

Originally Posted by Smith Point

Ken, I’m telling you that this was a long time ago, in the early 70s
The question still remains, do they draw down the lake every 10 Years? For shore line repairs?

We get a drawdown 2 out of every 9 years. November 1st will see Sebago Lake 5.5 feet below full pond. Good thing there's not too much boating as there are navigational hazards galore.

[AC2717]

Yesterday did anyone else notice how high Winnisquam was? I know it is smaller than Winni but I thought with all that rain it would have came up a little bit

[kchace]

Originally Posted by Smith Point

Ken, I’m telling you that this was a long time ago, in the early 70s
The question still remains, do they draw down the lake every 10 Years? For shore line repairs?

Well I'd say the answer has to be no. On Bizer's website under lake level, you can see what the levels have been for every year since 1984 and none go bascially out of similar ranges. If there was a major drawdown, it would show as a line much lower than all the rest.

Ken

[jrc]

If you go to the Bizer site and follow the links to the Dam Bureau. Look around and you'll see a drawdown schedule. There you will seem a note that in effects says that there is no regularly scheduled drawdown of Lake Winnipesaukee. It's a little ambiguous but that's the most definitive thing I could find.

[KEEPER]

Nothing out of the ordinary is planned for this fall. I've attached the current ops procedures for the big lake. It's a bit of a read, but informative.

Lake Winnipesaukee Operating Information

Water Level and Flow Constraints:

June 1 through Columbus Day (Summer Recreation Season)
To the extent that weather conditions allow, levels are managed between 504.32 and 502.80 to facilitate the use of the lake for recreational enjoyment. Depending upon events and forecasts lake levels are allowed to climb to 504.80 (about 6 inches above full) for short periods of time to allow discharges at Lakeport to be managed to alleviate or lessen downstream
flooding/flood peaks and to avoid exceeding the capacity of downstream hydropower plants. Currently, a considerable amount of judgment is applied when making decisions regarding flow release during these “high water” periods. Since the wasting of water in excess of the hydropower capacity at Lakeport Dam (1,050 cubic feet per second (cfs)) is of concern, the
decision to do it is based upon factors such as: rate of rise (inflow), soil moisture condition, basin vegetation status, precipitation forecast and estimated length of time to return levels to within the normal range. When levels reach 504.50+/-, the number of complaints regarding shoreline structure damage or usability increases. This 71-square-mile lake has hundreds of permanent and seasonal homes with varying degrees of shoreline development When the level rises much above the full pond level of 504.32, impacts begin to occur. There is at least one marina that experiences problems with bridge access (low clearance) when levels begin to climb above full.

Issues associated with the lower end of the summer recreation range relate to hull/motor damage to boats and, like high water, to structure usability. Many abutters are accustomed to a certain range of water levels during the recreation season. However, when the lake is at the lower end of the range, docks and other structures may become less accessible (ex: hull draft is larger than depth at dock). The 250 cfs minimum outflow at Lakeport Dam can sometimes far outpace inflow during the summer recreation season and this, combined with normal summer evaporation, will cause the lake level to typically drop 12 to 15 inches over the course of the summer.

Columbus Day through December 31st
To the extent that weather conditions allow, the lake level is managed between elevations 503.00 and 503.50 during this period by releasing water at a rate that can be fully utilized by the downstream hydropower plants (250 to 1,050 cfs). This is done to facilitate shoreline property maintenance. If deemed appropriate, and based upon basin conditions and weather forecasts, levels will be allowed to climb above this range to prevent releases at Lakeport from exceeding 1,050 cfs. When the level begins to encroach on the full summer elevation (504.32), releases will be increased beyond the capacity of the hydropower plants to make lowering the lake level the first priority. DES also endeavors to reach a target level of approximately 502.80 on December 31st, which is approximately six inches above the full
drawdown depth of two feet. The water stored in this remaining six-inch band is release during the coldest months of January and February.

January 1st through May 31st
To the extent that weather conditions allow, water is released from Lakeport Dam to reach the full 2-foot drawdown (502.32) in the lake by about the end of the first week of March. The actual depth of the drawdown varies from year to year depending upon meteorological conditions; including prevalent base flow rates and snowpack. From March through May 31st the lake level
is allowed to climb as snowmelt, soil moisture and lake ice conditions allow. Discharges at Lakeport Dam are made based on both actual and predicted weather events. Ideally, flows will be maintained between 500 and 1,050 cfs throughout the period. During extremely cold periods, flows lower than 500 cfs cause frazzle ice to form along a steeply sloped reach upstream of
Franklin center, causing maintenance problems and reduced turbine efficiency at the local hydropower stations.

Summary of Operation Under Normal Conditions:
Lake Winnipesaukee is filled to between elevation 504.10 and 504.32 by June 1st. From June 1st to Columbus day, Lakeport Dam is operated as necessary, and in conjunction with other dams along the reach depending upon prevailing conditions, to maintain a minimum discharge of 250 cfs and to keep the lake from rising to more than 6 inches over full (504.80). Natural
meteorological conditions, coupled with the minimum discharge, typically cause the lake to gradually drop during the months of July through October. On or near Columbus Day, a two-week shutdown of flows at Lakeport Dam is initiated to facilitate maintenance in the river reach from the dam to the confluence of the Winnipesaukee and Pemigewasset rivers. After the
shutdown, discharges are returned to between 250 and 1,050 cfs, depending upon prevailing runoff and water level conditions within the basin, to facilitate the generation of hydropower. These increased flows are maintained until the lake level drops approximately 1.5 feet to elevation 503.00. Once this level is reached, the releases are managed so as to provide for a lake level at or slightly above this elevation on January 1st. Additionally, DES endeavors
to maintain a discharge between 500 to 750 cfs through the extremely cold months, as lower flows during these periods promote the formation of frazzle ice, which complicates the operation at some of the hydropower facilities. The objective is to achieve a maximum drawdown elevation of 502.32 in late February or early March, and then begin refilling the lake in mid to late March depending upon forecasts and the extent of the snowpack.

Summary of Operation Under Flood Conditions:
Releases from Lakeport Dam are kept to a maximum of 1,050 cfs (the maximum capacity of the hydropower plant at Lakeport), if possible. If the lake continues to rise or if more rain is forecast, releases at Lakeport Dam are generally increased in stages of 250 - 500 cfs per day, and flows are adjusted at the other dams along the river to keep pace with these releases and local inflow. Flows above 1,050 cfs are achieved by operating the hydro plant at maximum capacity and incrementally opening the dam’s 3 large floodgates. After the peak of the flood has passed, and after flows in the lower portion of the basin have had an opportunity to recede, flows at Lakeport Dam are increased and adjusted to keep the lake level receding
until it returns to the approximate level for that time of year. Any changes to the discharge at Lakeport Dam are made in consideration of the effects of those changes on the downstream reach.

The Weirs channel, which is relatively narrow and may be as little as 5 to 6 feet deep in some areas under full lake conditions, may act to back water up into Lake Winnipesaukee during high runoff events. In addition, the measuring flume just upstream of the Lakeport Dam may inhibit the ability to pass water downstream. However, the capacity of the flume exceeds other
constraints to flow downstream of Lakeport Dam. Therefore, the flume is not considered a limiting factor in flood operations.

Drawdown

Although Lake Winnipesaukee is operated within a 2-foot wide operating band, there isn't a traditional drawdown of this lake as experienced by many other smaller impoundments throughout the state. Rather, the traditional 9 to 12 inch drop of the lake level experienced through the summer is maintained through the Fall season. Then in January, flows are increased
at Lakeport Dam to gradually lower the lake to about elevation 502.32 - or 2 feet below full lake. This level is usually reached in late February or early March.

[islandAl]

great info, very hard to manage Mother Nature
Althewhile trying to keep the big lake and downstream factors in mind.

[Smith Point]

Keeper, where did you find this information?
Do you know if they (the dam people) would conceder a scheduled draw down? Not only to work on our shoreline, but to find possible unknown water hazards, and also keep the milfoil problem in check.

I think that the benefits of a scheduled draw down “off season” (say the month of November) would outweigh the inconvenience for pleasure boaters for a short period of time so there can be work done on our property as well a dam inspection, hydropower facilities inspections etc.

[Blue Thunder]

Originally Posted by Smith Point

Keeper, where did you find this information?

I'd say from his post and his screen name that he is a Dam Keeper on Winnipesaukee or at least someone who knows an awful lot about it.

JMO

BT

[Skipper of the Sea Que]

Originally Posted by Blue Thunder

I'd say from his post and his screen name that he is a Dam Keeper on Winnipesaukee or at least someone who knows an awful lot about it.

JMO

BT

You are right. He's the dam go-to guy.

Keeper introduction message from a 2006 thread.

I sure do appreciate KEEPER's input here on the Winnie Forum. I don't want to hijack the thread and convert it to a "thank you" string of messages - we'd probably run out of server storage space . Thank you for popping in here on the Forum. I'm sure I speak for 99% of forum users - I figure that 1% or less are the few who always will disagree with anything .

Thank you KEEPER for your dam coordination and your input to the forum.

I'd add a few dam jokes but I'm sure KEEPER has heard them all - probably more of them than any of us have.

[SteveA]

Couldn't resist...

[SIKSUKR]

Yup,there is a good "FLOW" of info here.

[Rattlesnake Guy]

Originally Posted by Skipper of the Sea Que

- I figure that 1% or less are the few who always will disagree with anything .

That sounds incredibly generous. You are a gentleman skipper.