Big Island Pond Dam

Part of Big Island Pond Corporation’s charter is to monitor and regulate the water level of Big Island Pond. This is done at the dam located at the end of Escumbuit Road in Derry, where our water empties into the Spicket River and downstream into Arlington Pond in Salem.

Our water level is checked and tracked on a regular basis by a BIPC representative, who works closely with the State of NH and Salem’s Department of Public Works to coordinate and regulate water flow. We try our best to keep our pond at a consistent level of 8.5 feet as measured at the dam. However, Mother Nature occasionally has other ideas. No one can accurately predict the timing, duration, and intensity of rain storms, and we appreciate your understanding that water levels will vary over the course of a season.

Each Fall, the dam is opened slowly to lower the lake (Usually on Oct 12th). This allows us to perform necessary dam maintenance activities and gives residents, who have secured proper permits, a chance to make repairs to their walls, docks, and other properties. Lowering of the water also offers a measure of weed control if plants are exposed to sustained periods of hard Winter freezes.

In the Spring,(Usually April) the dam is closed after the ice melts, and Big Island Pond refills with water from underground springs and upstream brooks.

Approximately two weeks after the dam is opened in the Fall, volunteers perform annual maintenance on and around the dam. Residents, families, and friends are welcome to participate and learn more about the maintenance process. If you’re interested in helping, Call Kenny Heinrich at 603-553-5224 or contact your Area Director for more information.

BIP Water Quality

BIPC tests the waters of Big Island Pond periodically during the year. As a member of the New Hampshire Volunteer Lake Assessment Program (VLAP), we supply volunteer lake monitors and the State supplies limnology laboratory equipment and processing of the samples. We particularly look for chlorophyll-a (a measure of algae), phosphorus (the primary nutrient for plant growth), E.coli bacteria (a measure of fishable and swimmable water), conductivity (an indicator of erosion/road salt runoff) and water clarity.

Regular testing allows us to observe trends that may be harmful to our pond. For example, we have noted that over the past 10 years, conductivity has increased greatly. We are now at levels above 200 uMhos/cm. In 1990, we were at 131 uMhos/cm. The NH state average for conductivity levels of a fresh water body is 62uMhos/cm.

You might ask — “Why is this important?” Conductivity levels are important because they are a signal that salts are polluting the lake in uncontrolled amounts. The primary cause for increasing chloride is salting highways for snow removal. Another contributor is water-softening systems, commercial and residential.

Do’s & Don’t’s

State and local laws regulate shoreline protection and water usage. Common courtesy and neighborly behavior makes lake life fun and memorable. We have listed a few Do’s and Don’t’s that could make lake-living more enjoyable for everyone. Check out links to local and state organizations.

Here are a few reminders:


  • Rinse your boat’s motor and trailer before using in another lake or launching a boat in BIP.
  •  Dispose of weeds AWAY from the lake so they do not wash back in and regrow.
  • Slow to minimum wake when passing sailboats, canoes and kayaks.
  • Know the location of your septic system and leaching area.
  •  Inspect your septic tank yearly; if sludge and surface scum combine as a thick 1/3 of the liquid depth of your tank, have the tank pumped out.
  •  Seek alternatives to dishwashing products containing phosphorus and bathroom cleaning products contain chlorine.
  •  Leave stumps and vegetation along water’s edge to minimize erosion.
    Be courteous of your neighbors. Avoid loud activities before 9am or after 9PM.


  • Dump sand into the lake.
    Flush toxic materials such as paint thinner, pesticides or chlorine into your septic system.
  •  Flush bulky items such as disposable diapers or sanitary items into the septic system.
    Bathe, wash animals, use soap of any kind or relieve yourself in the lake.
  •  Use high-phosphorus fertilizers near the shoreline.
    Dump leaves or grass in or around the lake.-
  • Throw cigarette butts, empty cans or trash of any kind in the lake.
    Shoot fireworks at or from boats.
  •  Spill gas in or near the lake.
    Use driveway salt. Conductivity levels in BIP are rising and this is a key contributor.
  •  DO NOT FEED THE DUCKS! It is returned into the lake as pollution and they start depending on others for their food.