Rivers and streams are sculpted by floods, and the land on either side of the water develops over geologic time into a floodplain, a relatively flat open or forested space which helps slow and absorb floodwaters. Floodplains provide unique wildlife habitats and a transition between the river ecosystem and upland ecosystem. The Connecticut River floodplain is known for having some of the richest agricultural soils in the world.

Regenerative agriculture utilizes farming practices that promote soil health through no-till farming, diverse cover crops, and integration of livestock. Organic matter and nutrients left behind after flooding helps enhance the soil, so it can absorb and hold more water, drain the water more efficiently, and reduce soil erosion and flood damage to crops.

Natural floodplains provide flood risk reduction benefits by slowing runoff and storing flood water. They also provide other benefits of considerable economic, social, and environmental value that are often overlooked when local land-use decisions are made.

Some of the other benefits of floodplains to a functioning natural system include:

• Fish and wildlife habitat protection
• Natural flood and erosion control
• Surface water quality maintenance
• Groundwater recharge
• Biological productivity
• Higher quality recreational opportunities (fishing, bird watching, boating, etc.)

Floodplains in Cornish have been mapped in four main areas:

• Along the Connecticut River
• Along Center Road, Townhouse Road, Jackson Road and Tandy Brook Road
• In Cornish Flat
• Along Blow-Me-Down Brook

According to the Association of State Floodplain Managers, there has been a dramatic increase in restoration projects to restore confined channels to natural channels, wider use of stream and river buffers to take advantage of the filtration capability of these areas to improve water quality, and an increased recognition of stream and river fronts as recreational amenities.

The key to safe and clean water is to keep it clean in the first place. Cornish has 3 primary streams (with numerous tributaries), and fortunately all 3 originate in Cornish. That ensures no pollution at their source, but we as residents have a responsibility to each other as neighbors, and those who live downstream to be good stewards. Eventually our pristine waters make their way to the CT River, or to the CT via the Sugar River, and the wider world. What can we do to keep our streams clean, clear, and safe?

The 3 Cornish streams include Whitewater Brook (in the SE corner of Cornish), Mill Brook and its many tributaries, including Center Brook (which drain through central Cornish), and Blow-Me-Down which drains through northern Cornish flowing through Cornish Flat and into Plainfield on its journey to the CT River, flowing by St. Gaudens National Historical Park.

Cornish brooks and streams were subject to intense use by mills prior to the 1840’s, but were spared completely from heavy industrial use during later years (unlike the towns of Claremont, Lebanon and Windsor). For a community that has no town reservoir or Town water supply, maintaining healthy groundwater and aquifers was as important then, as it is today. (Also see Conservation Note 2022 #1)

Stream quality can be impacted in 3 primary ways.

DIRT. Rain washes dirt into streams and rivers from roads, fields, construction, and logging sites. If enough dirt washes into a stream, it can alter the habitat for the fish (smothering fish eggs, and reducing water visibility), or even killing bottom dwelling organisms like crayfish or other important aquatic insects. Needed water plants may not grow if the water is too murky. Minimizing disturbance of the land alongside and abutting streams is the first step in reducing sediment pollution from dirt.

BACTERIA.  Not all bacteria are harmful, but germs and viruses that make us sick can be in water, unseen and undetected.  Too much animal waste from farms, or from overabundant wildlife, or even pets can pollute streams and cause sickness. So it’s really important to do all we can: use appropriate farming practices when raising livestock so their waste products are kept out of streams, manage wildlife herds to reduce the impact of overpopulation on water sources, taking care to properly dispose of our human trash, garbage and waste, including cleaning up after our pets. These are actions we can take to help keep water safe for all living things, as well for our many human needs.

NUTRIENTS are needed for all living organisms to grow, but if 2 common elements in particular (nitrogen and phosphorus) are over abundant in our streams and rivers or lakes, then too much algae will grow and aquatic life can suffer and even die. Minimizing the use of fertilizers and pesticides on our lawns, gardens, and farms, and along roadsides will greatly help.

Fortunately we do not have factories or big manufacturing or mining companies that release harmful chemical or by-products directly into our Cornish streams. But we all need to control the chemicals that leak from our vehicles and equipment, garbage/trash, salt on our roadways, or other chemicals capable of polluting our precious water.

Everyone must do his/her part to keep our water safe and clean for us as the current residents, and for the future generations that will live here.

Additional Reading:

Cornish Water Resources

My Healthy Stream

NH Wildlife Action Plan – Pollution Chapter

Unlike many communities, Cornish has no reservoir or Town water supply, so we must depend on groundwater, aquifers, shallow wells, and springs for our water supply. Groundwater and aquifers are terms that are often used interchangeably, because these sources of drinking water are both found in rock, sand and gravel deposits below ground. Rain and snowmelt recharge the groundwater resource, and water availability may be affected by drought conditions.

Groundwater and aquifers are protected by state regulations that cover septic systems, waste disposal sites, agricultural runoff, underground fuel storage tanks, and other facilities that could negatively affect aquifer and groundwater quality.

The National Groundwater Association (LINK) has published a list of what residents can do to protect and conserve groundwater.

• Use native plants in your landscape. They support pollinators, vital to our food supply, and generally don’t need extra watering or fertilizer.
• Reduce Chemical Use. Use fewer chemicals around your home and yard, and make sure to dispose of them properly at a community hazardous waste collection event – don’t dump them on the ground or down the drain.
• Manage hazardous waste. Properly dispose of potentially toxic substances like unused chemicals, pharmaceuticals, paint, and motor oil. The Upper Valley Lake Sunapee Regional Planning Commission hosts household hazardous waste collection days – see the 2022 schedule at this LINK.
• Use all natural/nontoxic household cleaners whenever possible. Materials such as lemon juice, baking soda, and vinegar make great cleaning products, are inexpensive, and environmentally-friendly.

View Groundwater Aquifers Map of Cornish: LINK