The
Sengekontacket Pond Watershed
The Friends of Sengekontacket, Inc. Would Like You to Know
About the Sengekontacket Pond Watershed
A
watershed is a geographic area of land in which all surface and ground water
flows downhill to a common body of water. While Sengekontacket Pond is about
750 acres, its watershed comprises over five thousand acres or 8.2 square miles!
It extends from a narrow point near West Tisbury center to Sengekontacket Pond.
(See map attached.) As water drains over the land, it carries vegetation, soil,
and sediment, dissolved materials, and pollutants downstream to recipient water
bodies, such as Sengekontacket. This is why use of the land for conservation,
housing, commercial, farming, a golf course, roads, or other development impacts
water quality.
In many places off-island the source of
potable (drinking) water is surface waters such as rivers, lakes, or
reservoirs. However, on Martha’s Vineyard, whether you have a private well or
are served by a municipal well, the source of your water is ground water. When
there is precipitation, the water contained in rain, sleet, or snow keeps moving
when it falls to the ground. Plants use some of this moisture and some
evaporates and returns to the atmosphere. Only about twenty-two inches of our
average forty-six inches of annual rainfall trickles through the layers of sand,
soil, and rock filling empty crevices between them and become ground water.
Since this is the only source of drinking water on the island, in 1987 the US
Environmental Protection Agency conferred a Sole Source Aquifer designation on
our drinking water. This acknowledges the lack of alternative sources of
drinking water, and increases responsibility for being stewards of this valuable
resource.
The purity of our drinking water and
health of our coastal ponds is closely linked. Sengekontacket Pond receives
water not only from Nantucket Sound but also from ground water. This mixing of
fresh and salt water creates “brackish water,” characteristic of an estuary.
Estuaries support an abundance of life and can be thought of as nurseries for
many kinds of finfish and shellfish.
Coastal ponds are particularly
susceptible to nitrogen enrichment. Nitrogen in fertilizer, wastewater from
septic systems, and atmospheric deposition (acid rain) stimulates plant growth.
Eventually algae grow so abundant that less light penetrates pond waters. Mats
of algae kill eelgrass, which cannot survive in low light conditions. (Eelgrass
is essential for juvenile bay scallop habitat.) Algae use dissolved oxygen in
the water for photosynthesis, which depletes the available amount of oxygen and
threatens shellfish and finfish survival. Dissolved oxygen is normally a major
indicator of water quality in a body of water.
In addition to your support of the Friends
of Sengekontacket to enable us to fund scientific studies to monitor, in part,
nitrogen and oxygen levels in Sengekontacket Pond, please see the back of this
page for individual actions you can take to preserve the Sengekontacket Pond
watershed. Be mindful that you do not have to live on the Pond to impact its
watershed.
Good Sengekontacket Pond Watershed
Practices to Post in Your Home
(Adapted with permission from a document
originally written by April L. Hamel and Lloyd Raleigh on behalf of the
Conservation Partnership of Martha’s Vineyard)
1. Landscape with native plants and
insect resistant species.
- Reduce the use of
synthetic fertilizers, pesticides, and herbicides.
- Become educated
about pesticide alternatives and biological controls.
- Leave a naturalized
buffer zone around water bodies. Plants help to absorb pollutants and keep
them from entering the Pond.
- You cannot alter
the natural vegetation within 100 feet of a wetland in Oak Bluffs and 2oo
feet in Edgartown without Conservation Commission approval.
2. Pump septic systems every two to three
years.
- Use phosphate free
detergents.
- Do not dispose of
solids, grease, oil, poisons of any kind, paint thinners, colored toilet
paper, medicines, disinfectants, coffee grounds, or any sort of hazardous
chemicals down your drains or anywhere on your property.
- Do not use a
garbage disposal if you have a septic system.
3. Make composting a daily routine by
keeping uncooked fruit and vegetable garbage, and coffee grounds in the kitchen
in a separate small closed container (sold at many Vineyard stores.) Empty the
container into a covered compost bin outside. The composted materials break down
over time producing humus. This odorless, brownish substance resembling moist
breadcrumbs is high in nutrients and can be used as fertilizer to enrich the
sandy soil when planting.
4. Hazardous chemicals such as motor oil
and other machine liquids should be securely stored. Make sure your vehicle,
lawn mower, boat, or any other combustion engine does not leak motor oil,
gasoline, antifreeze, or other chemicals. Recycle any unused machine liquids.
Do not dispose of them in the trash.
- Take hazardous
waste to the Island Waste Recycling Stations. Days when medications,
solvents, old oil filters, motor oils, anti-freeze, pesticides and
herbicides, oil based paints, paint thinners, batteries, poisonous
substances etc. are accepted is announced in local newspapers. For more
information, call 508-627-5482 in Edgartown and 508-693-5502 in Oak Bluffs.
5. Practice water conservation in your
home.
- Do not leave water
running when brushing the teeth, shampooing hair
- Water your lawn and
bushes early in the morning and in the evening when there is less
evaporation.
- Cut grass long to
protect roots from the summer sun.
- When washing a
vehicle, use biodegradable soap and water sparingly.
- When cleaning a
boat, use a scrub brush and no soap.
- Use reduced-flow
showerheads and faucets. Repair leaks promptly.
Add your suggestions to this list, copy
it, and give it to your neighbors. Encourage others to take care of the
Sengekontacket Pond watershed.
Friends of
Sengekontacket, Inc.
PO Box 740
Edgartown, MA
02539
Telephone: 508 627 6966
Fax: 508 627 5833
Email:
info@sengekontacket.org
Website: www.sengekontacket.org