State Announces Its 2019 Fall Drawdown of Lakes
Concord, NH – The New Hampshire Department of Environmental Services (NHDES) announced today that the annual fall drawdown of the lakes and ponds controlled by dams owned by NHDES will be initiated according to the schedule. (Request a schedule from NHDES.)
1. Archery Pond - located in Bear Brook State Park will be drawn down for no more than a week to facilitate minor repairs to the dam. This work will begin October 28th and the pond level will be returned to full pond after the work is complete.
2. Chesham Pond - in Harrisville will begin an early drawdown to allow for the continuation of reconstruction work on the dam.
3. Grafton Pond - will be drawn down 8 feet for a two to three-week period for inspection of the dam. This drawdown will start on Sept. 30th and the lake level will be returned to its normal drawdown level of minus two feet after inspection is complete.
4. Kingswood Lake - will have a deeper drawdown beginning on Sept. 30th to help with repairs to the dam. The lake level will return to its normal drawdown after work is completed on the dam.
5. Lovell Lake will be drawn down one extra foot from three feet to four feet in accordance with its 4-year drawdown cycle.
6. These larger lakes generally do not reach their full drawdowns until mid or late March. The values listed above are generally the maximum levels reached, although during any given year the levels reached can be either higher or lower due to weather conditions.
7. Ossipee Lake - draw down will begin on Sept. 15th this year to accommodate construction of the replacement of the dam’s spillway. Starting on that date it will be drawn down to elevation 406, or 1.25 feet below full, and held there until Columbus Day, at which time it will be lowered to the usual full winter drawdown by opening up all the dam works.
The depths of drawdowns listed in the table above are not from the current level, but are from the normal full pond levels. Due to changing ice and hydrologic conditions, these levels can vary throughout the winter. Since the hydrologic conditions and recreational uses of these water bodies vary, the degree and date of the start of drawdown for each lake vary and could be affected by the amount of rainfall during the period. In addition, the actual date at which the drawdown will begin could vary by a few days based on operational constraints. However, at three dams, the drawdowns will be initiated or accelerated on a specific Saturday in October to provide recreational opportunities for canoeists and kayakers in the rivers below these dams. The schedule for these recreational opportunities is as follows:
- On October 12th, approximately 450 cubic feet per second (cfs) will be released into the North Branch of the Piscataquog River from the Horace Lake Dam in Weare.
- On October 19th, approximately 250 to 300 cubic feet per second (cfs) will be released into the Little Suncook River from the Northwood Lake Dam in Epsom.
- On October 26th, there will be a release performed by Eagle Creek Renewable Energy into the Piscataquog River from Gregg Falls Dam in Goffstown, dependent on weather conditions.
These special releases will start at or near 8 AM for the dates specified above for the Horace Lake Dam and the Northwood Lake Dam, and 10 AM for the Gregg Falls Dam. At the first two the flow will be reduced to near normal levels by 4 PM that same day. DES reminds people that canoeing and kayaking have inherent risks, and paddling the state’s lakes and rivers is at the paddler’s own risk.
Lake drawdowns are conducted each fall to reduce winter ice damage to shoreline properties and to reduce spring flooding. Drawdowns also give property owners an opportunity to conduct any necessary repairs to their waterfront property, provided they first secure a permit from the NHDES Wetlands Bureau at (603) 271-2147.
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, in the fall after 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. This year the reduction will begin on October 14.
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 the Dam Maintenance page. Also included are updated plots of this year’s lake levels, releases from the dam, and precipitation.
The NH Fish and Game Department recommends that if special drawdowns are to be conducted for the purposes of repairing property such as retaining walls or private boat ramps they occur only once in every 5 years. In the event a party may wish to conduct such a drawdown, please contact the DES Dam Bureau immediately after receiving all permits required for such work, so that the drawdown can be coordinated with any other work being proposed on the same water body. In this way the number of special drawdowns can be minimized, and unexpected delays (up to 5 years) for projects can be avoided.