Why should we protect Lake Ivanhoe?

Lake Ivanhoe’s high water quality makes it a valuable asset to the community on numerous levels: economic, recreational, ecological, and cultural.

  • Once a lake has declined, it can be difficult or impossible to restore. Prevention is the key.
  • A 3-foot decline in water clarity could reduce property values as much as 20%. A large portion of Wakefield’s revenue is derived from waterfront property taxes, which are based upon property value. Therefore, maintaining a clean, clear lake is crucial to the town’s financial viability as well as protecting the investments of property owners.
  • The lake draws in anglers from across the region. The convenient location thus draws weekenders from out of state who flock to the area to pursue leisurely activities. The small size of the lake and clarity make it ideal for swimming, sailing, canoeing, and kayaking.
  • Fishing is a popular activity thanks to the abundance of fish species including: smallmouth bass, American eel, chain pickerel, lake trout, largemouth bass, rainbow smelt, white perch, and yellow perch.
  • In addition to the numerous fish species, bald eagles and other large birds of prey utilize the lake habitat for hunting, nesting, and breeding. Nesting loons are a frequent site and have become a symbol of the region with only a few hundred nesting pairs in the entire state. Declining water quality could force these majestic birds to find a different and healthier waterbody to call home.
  • A clean lake with clear water is perceived as being a community asset. Healthy lakes are regarded as being more valuable and desirable. The lake becomes a source of community pride to its users and fosters a sense of stewardship.
  • Sediment deposited into the lake from erosion creates the ideal environment for invasive aquatic plants to thrive.

Water Quality

Water Monitoring Program

The UNH Lay Lakes Monitoring Program (LLMP) and Center for Freshwater Biology (CFB), and NH Department of Environmental Services (NH DES) have collaborated in the collection of lake data to collect water quality data for Lake Ivanhoe in order to evaluate present water quality, track algae blooms, and determine water quality trends.

Water quality monitoring data for Lake Ivanhoe has been collected since 1991. This includes 16 years of Secchi Disk Transparencies, 17 years of phosphorus data, 16 years of chlorophyll-a and color data, and 14 years of dissolved oxygen profiles.

The New Hampshire DES’s most recent (1992) trophic state index (TSI) determination numerically ranked the trophic state of Lake Ivanhoe as 1. NHDES calculates TSI from summer bottom dissolved oxygen, summer Secchi Disk Transparency (SDT), aquatic vascular plant abundance and summer epilimnetic Chlorophyll-a. This tropic classification system also accounts for lake stratification (Lake Ivanhoe is not stratified). Stratified lakes with TSI values greater than 6 may support algal blooms (for unstratified lakes this value is 4), while TSI values over 12 indicate extreme productivity and annual algae blooms (for unstratified lakes this value is 9). New Hampshire DES considers the water quality of Lake Ivanhoe to be high based on measures of SDT, aquatic plant abundance, and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Lake Ivanhoe is therefore low.

Water Sampling

The UNH Cooperative Extension interns collected water samples from Lake Ivanhoe on July 23, 2018. This is the second time a sample has been collected this season.  There are two more sessions scheduled this year.  The data from this activity gives us valuable insight into the current water quality of the lake and allows us to understand how we are trending. Thanks to the Luke’s who provide their boat to transport the sampling team and for recording data.  Beth Luke was at the helm – go Red Sox! .

Comparison to our Neighbors – 2019

LakeWater Clarity
Great East Lake10.4 / 11.01.3 / 0.74.2 / 4.46.6 / 8.4
Wilson Lake6.
Lovell Lake6.6 / 6.72.7 / 2.76.9 / 8.10.5 / 3.3
Horn Pond7.
Lake Ivanhoe5.0 / 5.63.7 / 2.18.8 / 9.3---

|2019 / Last Reading| – Ivanhoe quality has degraded since last year especially relative to our neighbors

Be on the Lookout


Cyanobacteria is toxic and exists in all lakes. Normally, it does not pose a problem. However, if the conditions are right (the same nutrients that feed algae feed cyanobacteria) then it can quickly spread, forming dense “blooms” on the water surface. These blooms look like blue-green paint mixed in the water. They can cause serious problems because many cyanobacteria species produce toxins that are dangerous to humans and wildlife. These toxins can be found not only in the water but in the air nearby. If you see or suspect a cyanobacteria bloom stay out of the water and report it to the Town Health Officer and the NHDES Beaches program (603) 271-0698. Also please notify the Round Pond Association so that we can notify our community.

For more information on cyanobacteria and its health effects, check out the EPA website

Cyanobacteria and the Lakes – Amanda McQuaid from NHDES discusses the importance of monitoring cyanobacteria. She provides details on how to identify cyanobacteria, what to do if you suspect a bloom in our lake and who to contact. Click [ ] in video for full screen.

Download the BloomWatch App for your smart phone. The app lets you snap photos, report, investigate and discuss potential blooms with the community

Invasive Plants & Animals

Freshwater aquatic invasive plants and animals are those that are not naturally found in New Hampshire’s lakes, ponds, and rivers. Because they are not native, they have no predators or diseases, allowing them to grow quickly and dominate the freshwater systems and impact the native plants, fish, and aquatic insects already present. Aquatic invasive species can lead to reduced shore front property values, water quality impairments, and problems with the aesthetic and recreational values of waterbodies.

New Hampshire now has a total of 74 infested lakes and 11 infested rivers, most containing variable milfoil as the primary invasive plant, while others have fanwort, Eurasian water milfoil and water chestnut, among other common species. Dozens of waterbodies also support the Chinese mystery snail, which is an aquatic invasive animal, and four waterbodies support the Asian clam, also an aquatic invasive animal.

NHDES encourages the Clean, Drain, Dry protocol, to ensure that your lake gear is free and clear of any potential invasive species or other contaminants:

  • CLEAN off any plants, animals and algae found during your inspection and dispose of it away from a waterbody.
  • DRAIN your boat, bait buckets, bilges and other equipment away from the waterbody, leaving your boat’s drain in the open position during transport.
  • DRY anything that comes into contact with the water.

Know the law. The New Hampshire Department of Environmental Services (NHDES) reminds boaters of a new law that went into effect on January 1, 2017 to prevent additional aquatic invasive species infestations. Specifically, the law prohibits any transport of any aquatic plants on recreational gear and related trailers, and goes further to require that boats and other water-containing devices be in the open drain position during transportation. Violators could face fines ranging from $50-$200. This law is being enforced by New Hampshire Marine Patrol, conservation officers and other peace officers.

If you see any plants or animals resembling the pictures below please contact NHDES at 603-271-2248 for positive identification or send us an email. Please snap a photo of the organism against an object of known size such as a quarter, pen, or your hand. Please note the location in the lake, and if possible, collect a sample.

Non-Invasive Plants & Animals

Freshwater aquatic non-invasive plants and animals are those that are indigenous or naturally found in New Hampshire’s lakes, ponds, and rivers. Typically these indigenous species are balanced within the ecology of the water body with natural predators and cycles. In most cases, they do not pose an ecological problem for the lake. For more information on natural plants and animals please refer to the Field Guide to Common Aquatic and Riparian Plants of New Hampshire. If you notice anything unusual such as an overabundance or bloom that is historically uncommon, please take a picture, note the location and let us know.

Freshwater Jellyfish

According to N.H. Department of Environmental Services, freshwater jellyfish have been showing up in NH lakes for some time. Although rare, they usually come in late summer when it’s been hot and dry, and when there are slightly more nutrients in the water.

The jellyfish start out in polyp form on the murky bottom of lakes and ponds. It’s only when the polyps develop a “medusa,” the outer orb of translucent membrane, that the jellyfish appear in the water column. A jellyfish is roughly the size of a quarter.

They don’t pose a threat to people. The medusa only persists for a few weeks at a time, and then they dissipate back into the polyp form. Only the right conditions trigger them into medusa form, they’re very short-lived. Check out this 2010 newspaper article which highlights jellyfish in Lake Ivanhoe.

Lake Ivanhoe – September 15, 2018

Lake Ivanhoe Weed Watch

The Lake Ivanhoe Weed Watch Committee consists of volunteers who patrol designated areas (zones) of the shorefront looking for invasive plants and animals that could negatively impact the lake and its ecosystem. The state recommends that inspection take place from the shoreline out 10 to 15 feet using both a parallel to edge and a zig-zag pattern over the area.

If a suspect weed or organism is encountered please do the following:

  • Take a photo of the item within the lake
  • Note the location of the item. Please use the lake map to indicate where the item is in the lake
  • Remove a sample of the item and take a photo of it on a white or neutral surface with an object of known size such as a quarter, pen or your hand
  • Send us an email and contact NHDES at 603-271-2248 for positive identification
For more information on native and non-native (invasive) plants and algae, please refer to Aquatic Plants & Algae of New Hampshire

Weed Watch Committee Volunteer Inspectors & Zones 2019

  • Zone 1 – Luke
  • Zone 2 – Bob/Sandy
  • Zone 3 – Roger
  • Zone 4 – Dave R
  • Zone 5 – Simon/Kelly
  • Zone 6 – Pat V
  • Zone 7 – Jodi
  • Zone 8 – Dave W

If you suspect an invasive species, send us an email and contact NHDES at 603-271-2248 for positive identification

Nearby Infestations

NHDES monitors invasive species across the state. Know your neighbors and where the problem areas are. The following is the December 2019 NHDES report for lakes in the area showing which lakes have infestations with the type of infestation.

If you have visitors or renters from these areas, or other areas with known infestations, who plan to use their watercraft, floats, rafts, or toys on Lake Ivanhoe, please help them perform an inspection to ensure no foreign organisms are introduced into our lake. Also, please make them aware that state law requires them to transport their watercraft with all drain plugs removed.