Water Quality

Lake Wicwas historical water quality data can be found at the NH Department of Environmental Services (DES) website here.  Zoom to, and click on Lake Wicwas.

Lake Wicwas consistently receives high marks for water quality. The Lake Wicwas Association performs regular tests for water quality to track quality and address issues, if any.

Each year a biologist from NH Department of Environmental Services (DES) joins us to take samples of water from (typically) 6 locations in Lake Wicwas. These samples are analyzed for a number of water quality parameters which help us assess the health of the lake and to identify any improving or degrading trends.

Water quality sampling on Lake Wicwas has been done to varying degrees and frequencies since 1990. During this period of time some years have been missed and the locations and tests performed varied somewhat. Since 2002 we have sampled every year with consistent locations and tests. We alternate between testing early and late in the season to better understand the seasonal variations. Given our relatively stable conditions, we are comfortable testing only once per year, although DES recommends testing 3 times per year.

In addition to the detailed results from the DES water quality testing, see the sections below for information on cyanobacteria, E. coli and phosphorus.

Water quality reports from DES


Cyanobacteria is a very old, naturally occurring bacteria, that lives in every water body in the world. It may first appear looking like paint chips suspended in the water, and later collect into a bloom, forming a blue-green scum. During this time, toxins are released and dogs should not drink the water, nor should people enter the water. The blooms last a day or two, or a few hours. We are fortunate to not have major problems with cyanobacteria at Lake Wicwas. However, we should be vigilant and report potential sightings.

cyanobacteria bloom - 2008-0815
cyanobacteria bloom
  • Click on this photo to see a larger image of this small cyanobacteria bloom.

  • Click here and here to read more about cyanobacteria from NH DES.  Studies are on-going concerning the known and potential dangers of these toxins.

  • Click here to read more about cyanobacteria from the New Hampshire Lakes Association.

  • If you find the blue-green bacteria please contact Marge or Dave Thorpe, our VLAP representatives, at (603) 279-5242, so that they can be checked and tested.

E. coli in Lake Wicwas

We are fortunate to have consistently low levels of E. coli at all locations in the lake. Levels of <10 counts/100mL are typical and often as low as <5 counts/100mL. For reference, swimming at beaches is curtailed when the level reaches 88 cts/100mL and state standards allow counts to reach 406 for open surface water.

Phosphorus in Lake Wicwas

Our phosphorus levels are low at the surface but increase significantly below the surface. Quoting from the DES Volunteer Lake Assessment Program (VLAP) literature: “Phosphorus is the most important water quality parameter measured in our lakes. It is the nutrient that limits the algae’s ability to grow and reproduce.” It also is a prime nutrient for weed growth and responsible for increasing amounts of cyanobacteria.

DES suggests phosphorus readings below 10 micro grams per liter (µg/L) are low/good. Of the 7 locations sampled in August 2010, 5 locations on the surface of the lake were at or below 5 µg/L. The deep spot measured 6.7 µg/L about 7 feet below the surface, 14 µg/L at about 20 feet and 27 µg/L at about 26 feet. These high readings below the surface are the result of increasing amounts of sediment and decaying plant material in the greater depths.

Clearly it is to our advantage to take preventive steps to limit phosphorus infiltration into the water. The most common sources are leachants from septic systems and runoff from land containing sediment, animal waste and phosphorus-containing fertilizers and pesticides. For Lake Wicwas, we should pay particular attention to the two streams that feed into the lake, Dolloff Brook and Blake Brook.

Lake Wicwas property owners can help reduce phosphorus-containing contaminants from being introduced to the lake:

  • Use garden and lawn fertilizers which are free of phosphorus.  Note that by state agencies report that New Hampshire soils are generally, naturally rich in phosphorus.

  • Insure septic systems are in good operating order.

  • Properly dispose of animal waste.

  • Maintain good sanitation practice by swimmers.

  • Signs promoting the Don’t “P” in the Lake program are available at the Town Hall in Meredith for those who wish to advertise their good practices and influence others to do the same.  Read the ode to this program, here.

Some programs and regulations are in place to aid in controlling phosphorus being introduced into the water:

  • A decade or so ago phosphorus in cleaning products (in greater than trace amounts) was banned by legislation. This legislation is credited by some to have reduced phosphorus introduction by 30%.

  • On July 1, 2010, New Hampshire House Bill 350 placed a similar ban on dishwashing detergents. However, a 2010 New Hampshire bill (HB 1299) to place such a ban on garden and lawn fertilizer failed to clear a legislative committee.

  • The New Hampshire Lakes Association has placed a high priority on getting this bill approved in the next session of the legislature.

  • In April 2010, Meredith and The Lake Waukewan Watershed Management Committee kicked off an education program called “Don’t Put “P” in the Lake”, the “P” being phosphorus-containing products or by-products. This program is now also sponsored/endorsed by The Lake Winnipesaukee Watershed Association, Lakes Region Planning Commission and the North Country Resource Conservation and Development Council with support from DES, EPA and NOAA.

Dave Thorpe
Chairperson, Water Quality Committee, Lake Wicwas Association