Aquifers And Watersheds—

Regional Planning Agency Inventories Water Resources

By Andrew Gorosko

The regional planning agency has created an electronic compendium of information on existing and potential drinking water resources in its ten member towns, compiling data on both subsurface aquifers and surface drainage basins, or watersheds.

The database will provide municipal land use agencies in the region with basic information for their land conservation and development decisions, with the goal of protecting the quality of existing and potential public drinking water supplies.

The Housatonic Valley Council of Elected Officials (HVCEO) has posted the water resource information on its website at www.hvceo.org/water/WATER.php.

Besides Newtown, water resource data is posted for Bethel, Bridgewater, Brookfield, Danbury, New Fairfield, New Milford, Redding, Ridgefield, and Sherman.

Jonathan Chew, HVCEO’s executive director, noted that it is the first time that the regional planning agency has posted the information on regional water resources on the Internet. HVCEO receives many queries about water resources, so posting the data seemed like a beneficial move, he said.

The water resource information will be revised by HVCEO, as needed, to keep the data current, Mr Chew said. The information will be a permanent aspect of the HVCEO website, he added.

The information will become a component of the HVCEO’s decennial 2007 Regional Plan.

State law requires that municipal planning agencies address water supply resource protection in their decennial plans of conservation and development.

While much attention in Newtown is focused on the Pootatuck Aquifer as a drinking water source, the town contains six other smaller aquifers. Newtown also contains two watersheds in the southern end of town, which collect surface water runoff for water supplies used by other municipalities.

 An aquifer is a geologic formation or deposit that is capable of yielding usable quantities of potable groundwater. Groundwater is found in three types of aquifers: stratified drift aquifers, till aquifers, and crystalline bedrock aquifers.

The stratified drift aquifer, which is typically a layered deposit of gravel, sand, and silt in valleys, is the type of aquifer listed in HVCEO’s mapping. It is a result of past glacial action. The high porosity among the millions of pieces of gravel and coarse sand contained within such aquifers creates a high storage capacity for water, making stratified drift aquifers useful as public water supply sources.

 The 26 major aquifers in the ten-town region listed by the HVCEO on the Internet are stratified drift aquifers of at least 100 acres, and possessing a saturated water thickness of at least ten vertical feet.

Pootatuck Aquifer

Located in east-central Newtown, this northward draining stream valley comprises about 3.9 square miles of direct water recharge area and 4.8 square miles of indirect water recharge. A very large portion, perhaps 80 percent, of the large Pootatuck Aquifer is composed of coarse-grained materials. Saturated water depth appears to reach 100 feet or more, and water quality is generally favorable, according to HVCEO.

The United Water Company obtains water for its Newtown customers from two wells located in the Pootatuck Aquifer, off South Main Street, near Sand Hill Plaza. United Water pumps an average of 437,000 gallons per day, with peak pumping demand of around 700,000 gallons per day. The two wells have a sustained yield of 1.5 million gallons per day, according to HVCEO.

Other wells in the Pootatuck Aquifer located near Fairfield Hills feed another public water supply serving the town offices at Fairfield Hills, Garner Correctional Institution, Reed Intermediate School, and the Nunnawauk Meadows senior housing complex. Additional future users of that water source may include businesses locating at a redeveloped Fairfield Hills core campus, according to HVCEO.

HVCEO lists six other smaller aquifers in Newtown as water resources.

 They include the Pond Brook Aquifer in the Hawleyville section, which extends northward from the area of Exit 9 of Interstate 84 to Currituck Road and includes an extension into Brookfield.

The Limekiln Brook Aquifer is in the vicinity of Route 302 in Dodgingtown and extends into Bethel.

The Upper Aspetuck Aquifer lies in the southwestern corner of town, along the Redding town boundary line. This aquifer follows the Aspetuck River along Poverty Hollow Road.

The North Branch Pootatuck Aquifer is found in south-central Newtown. It lies below a flat area that is adjacent to the North Branch of the Pootatuck River. The aquifer is bound on the south by Palestine Road and Platts Hill Road. The aquifer is crossed by Beaver Dam Road and Brushy Hill Road.

The Deep Brook Aquifer lies along wetlands near Route 302, originating near Head O’ Meadow Road.

The Newtown at Housatonic Aquifer lies on the west shore of the Housatonic River, upstream of the Housatonic’s confluence with the Pootatuck River. The aquifer is below the flat terrain between the river and Walnut Tree Hill Road. The Housatonic Aquifer is considered a potential future public water supply source.

“United Water is presently looking in the Sandy Hook area [the Newtown at Housatonic Aquifer] for distant future use unless the need arises sooner. Another [water supply[ option is an interconnection with the Aquarion Water Company at the Monroe Town Line that would be used for emergency supply,” according to HVCEO.

 

Watersheds

Besides the seven aquifers located in Newtown, the town contains sections of two public water supply watersheds that are water sources for people in other municipalities.

Part of the Aspetuck River Watershed lies in the southwesternmost section of town, occupying about 2,060 acres there. The watershed, which lies along Poverty Hollow Road, drains through the town of Redding to the Aquarion Company’s Aspetuck Reservoir located in Easton and Fairfield. Some of the water in that water supply system is then pumped to Ridgefield for its use, according to HVCEO.

About 80 acres near Lantern Drive, lying west of South Main Street near the Monroe town boundary, is part of the Pequonnock River Watershed. Water draining through that watershed flows to the west branch of the Pequonnock River and is then diverted in Monroe to the Easton Reservoir, which is owned by the Aquarion Company.

Based on the number of requests that HVCEO receives for information on water resources in the region, the agency decided to post such information on the Internet to make it easily accessible, Mr Chew said.

Besides water resource issues, the regional planning agency addresses emergency response planning, transportation projects, traffic studies, railroad and bus issues, and affordable housing, plus demographic data.