DANBURY, CT WATER
Each of the ten municipal plans of conservation
and development has policies towards aquifers and water supply
and the other nine have been copied and placed
into one regional file to facilitate comparisons.
Sugar Hollow Aquifer: In the southernmost
section of Danbury, primarily to the east of Route 7 and shared
with Ridgefield and Redding, is located the Sugar
Hollow Aquifer. This resource includes an area
of 310 acres of saturated thickness of ten feet or greater.
(All acreages below represent this same variable).
Pond over Danbury's
Sugar Hollow Aquifer.
Photo courtesy of Rick Gottschalk.
Kenosia Aquifer: Moving north up Route 7 and
located under the Danbury Airport and Danbury Fair Mall is
the large Kenosia
Aquifer, 1,640 acres, extending to the north
side of Lake Kenosia and then westerly along I-84 to the intersection
of Route 6 and Aunt Hack Road.
Still River West Aquifer: The next aquifer
in Danbury is in the center of the City. This is the 1,120
River West Aquifer. Centered on White Street,
it extends north on the east side of Main Street to I-84.
On its south side it follows Main Street into Rogers Park,
also continuing easterly along the railroad right of way and
along Shelter Rock Road.
Great Plain Aquifer: Then due north is the Great
Plain Aquifer, with an area of saturated thickness
of ten feet or greater of about 290 acres. Its location is
along the relatively level land along Great Plain Road, east
of Danbury Town Park and north of I-84.
Still River Middle Aquifer: To the east of
this resource is the Still
River Middle Aquifer. This aquifer begins in
the I-84 & Route 7 interchange area and extends northeasterly
along the Still River between Federal Road and Route 7.
East Swamp Aquifer: Turning to the south along
the Danbury - Bethel border, the East Swamp Aquifer enters from Bethel.
It follows Limekiln Brook and extends north to Newtown Road
and almost reaches I-84 Exit 8. There are 870 acres of saturated
area of ten feet or greater.
Sympaug Brook Aquifer: To the south, a very
small portion of the Sympaug
Brook Aquifer crosses over from Bethel along
CT EXISTING AND
POTENTIAL WATER SUPPLY WATERSHEDS
42% of Danbury's total land area is in use as public water
supply watershed. This includes both Danbury's own substantial
watersheds and those in use for other communities. Some of
the water drained from these lands is used as water supply
within Danbury and some drains out of the town and is used
While Danbury has its own well defined internal need
for additional water supply, its supply system
may also be a source for other communities, as shown in this 2006 HVCEO report.
the Housatonic Valley Region’s central city, ranks third
of the ten municipalities in the region in terms of total
land area used for water supply drainage, following Redding's
87% and then Ridgefield at 62%.
zoning regulations maintain a protective overlay zone for
the existing water supply watersheds within the City. Not
just Danbury’s own water supply watersheds are covered
but those of Bethel, New York City and the Aquarion Water
Company as well.
a result, development applications and permits are subject
to some limitations and additional scrutiny. A citywide hazardous
substance management ordinance complements the zoning overlay.
Croton River Watershed: The extreme northwestern
corner of the City, about 1,000 acres of land, drains westward
towards the East Branch of the Croton River in Town of Southeast,
N.Y. This is part of the Croton River Watershed.
East Branch Reservoir in nearby New York State.
from this area flows to the East
Branch Reservoir and from there to the Croton
Reservoir for consumption in New York City and environs. This
use of Danbury’s water by New York City for water supply
purposes began back in 1842.
The Kenosia Watershed in western Danbury is centered along
the I-84 corridor. This supply shed designation dates from
1984 when Danbury added piping to make it possible to use
surface water in Lake Kenosia for supplemental water supply,
pumping it only on rare occasions northward to the West Lake
Kenosia diversion is designed as a flood skimming operation
and therefore Lake Kenosia storage is not utilized in the
calculations of safe yield. The pump station has the capacity
to divert up to 9 million gallons per day from Lake Kenosia
to West Lake Reservoir, but only during the non-swimming season,
and only when West Lake Reservoir does not fill from other
water supply watersheds.
of Lake Kenosia water supply watershed in Danbury is about
3,020 acres. Additional upland acreages for this watershed
are located to the southwest, within adjacent Ridgefield,
CT and in adjacent New York State.
an important state policy change was made regarding the status
of the Kenosia Water Supply Watershed. Rather than identifying
on the State Plan Map that area’s remaining vacant lands
along I-84 as in the Conservation Category, these would now
be classified as part of the Urban Growth Category, thereby
allowing state support for more intensive development than
OPM staff notes from 1997 identify the following summary of
public comment on the issue and resulting OPM recommendation:
Change the Lake Kenosia, Class II public water supply area
in western Danbury along I-84 from Conservation to a Growth
Area. The Housatonic Valley Economic Development Partnership
has designated this section of Danbury as the area of greatest
economic development importance within the region. Lake Kenosia
can only be used in a water supply emergency. Withdrawal is
limited to the winter months and the water supply has not
been used since it was first designated in 1981.
has enacted strict controls on the type of development that
may take place in the watershed of Lake Kenosia. Stormwater
drainage requires pretreatment. A maximum of 50% of a lot
may be developed if there are environmentally sensitive areas
on the lot. A watershed management plan is in preparation.
If Lake Kenosia is permanently lost as an emergency water
supply source, there are other sources within the region that
may be substituted in the future.”
The OPM staff record continuing, “Recommendation: It
is recommended that the Class II type lands within the Lake
Kenosia watershed between the water body and the New York
border be changed from Conservation to Growth because: 1)
this area is of the very highest importance to the region’s
economic health; 2) the very low marginal value of the water
resources for drinking water purposes; 3) adopted water supply
plans call for expanding drinking water resources in other
areas, and 4) extensive implementation of local regulations
that focus on the continued protection of water resources
from the impacts of new development.”
Kohanza Brook Watershed: The Kohanza
Brook Watershed (West Lake Reservoir system) occupies much
of western and northwestern Danbury. The best landmark to
serve as a dividing line with the Padanaram Brook Watershed
(Margerie System) is the ridge along which runs Route 39.
The Boggs Pond Reservoir, feeding into West Lake Reservoir,
dates from 1905.
Photo courtesy of Rick Gottschalk.
to the Danbury Water Department's 6/2003 Water Supply Plan,
"The safe yield of the West Lake System is 4.9 million
gallons per day. The West Lake System consists of West Lake
Reservoir, Boggs Pond, Upper and Lower Kohanza Reservoirs,
Lake Kenosia Diversion, and the Kenosia Well Field."
Padanaram Brook Watershed: The Padanaram Brook
Watershed (Margerie Reservoir System) occupies
much of western and northwestern Danbury. Margerie Reservoir
itself was built in 1935 and went into operation in 1937.
to the Danbury Water Department’s 6/2003 Water Supply
Plan, "The safe yield of the Margerie surface water supply
system is 3.3 million gallons per day. The Margerie system
consists of Margerie Reservoir, King Street Diversion, East
Lake Reservoir, and Padanaram Reservoir. The proposed Ball
Pond Brook and Lake Candlewood Diversions would be included
in this system in the future."
See also the CT Department of Public Health's assessment
report for the Kohanza Brook and Padanaram Brook
Ball Pond Brook Watershed: Ball Pond Brook
runs easterly through New Fairfield to Candlewood Lake. Its
drainage area includes Short Woods Brook as a major tributary.
The entire Ball
Pond Brook Watershed occupies a large central
portion of New Fairfield but only about 125 acres in Danbury.
This is along Bear Mountain Road near the New Fairfield Town
For many years the waters of Ball Pond Brook have been under
consideration as a future supplemental source for Danbury's
nearby Margerie Reservoir.
Candlewood Lake Watershed: If Danbury ever
taps Candlewood Lake as a water supply source then that part
of the Candlewood
Lake Watershed that lies within Danbury, primarily
the vicinity of Danbury Bay, would also become existing, rather
than potential, water supply watershed.
Saugatuck River Watershed: All of the land
in the southern panhandle of Danbury, on the south side of
the divide from the City’s Still River Watershed, is
part of the Saugatuck River Watershed draining to the Saugatuck
Reservoir in Redding. The total land area in Danbury drained
south to the Saugatuck Reservoir is about 2,780 acres.
8) Sympaug Brook Watershed: Also in southern Danbury, on the Still River side of the drainage
divide and near the Bethel Line, are found Mountain Pond,
draining down to Eureka Lake, and their associated water supply
watershed areas. These small reservoirs in the Sympaug
Brook Watershed are owned by the Bethel Water
Department and contribute water to the Town of Bethel to the
Their drainage area occupies only about 400 acres of southeastern
Danbury. Some additional acreage right on the Danbury-Bethel
Line is part of the Murphy’s Brook drainage area, a
reserve supply on occasion pumped from the Brook up to Eureka
OF STREAMS IN DANBURY
The Connecticut Department of Environmental Protection (CT
DEP) has developed water
quality standards in conjunction with the principles
of the federal Clean Water Act.
As a result each stream or water body in the Region has two
classifications, one for existing use, and one for ultimate
future use, written in a existing/future format such as "B/A"
or "A/AA". The highest standards are reserved of
existing and potential water supply areas, which are AA.
seeks to bring every water body in the State to a minimum
classification of "B" or better, which would not
be suitable for human consumption without treatment, but could
be suitable for recreational use, fish and wildlife habitat,
agricultural and industrial supply, and other legitimate uses.
is a non degradation policy such that stream now AA or A cannot
be reduced to B to allow discharges from industries or treatment
plants. The classification system and application to Danbury
is summarized below:
AA: Designated uses are existing or proposed drinking
water supply, fish and wildlife habitat, some recreational
use, agricultural and industrial supply. Discharges severely
A: Designated uses is potential drinking water supply;
fish and wildlife habitat; recreational use; agricultural
and industrial supply and other legitimate uses including
navigation. Discharges severely restricted. No reclassification
of A or AA allowed down to B.
B: Designated uses are varied and include discharges
from industrial and municipal wastewater treatment facilities
providing Best Available Treatment and Best Management Practices
are applied. All water bodies must eventually reach the minimum
standards of the B classification.
C and D: Indicates unacceptable quality, the goal
is Class B or Class A and DEP will issue orders to require
1. Candlewood Lake due to wastewater pumped
up from the Housatonic River: B/B.
2. Eureka Lake and tributaries: AA/AA.
3. Hudson River tributaries reaching into
northwestern Danbury from New York State: AA/AA.
4. Kohanza Reservoir and upstream tributaries:
5. Kenosia Lake tributaries: AA/AA.
6. Limekiln Brook flowing from the Bethel
Line northerly to the Still River: C/B. Also an unnamed tributary
stream on the west side of old Danbury landfill flowing northerly
to Limekiln Brook: B/B .
7. Margerie Reservoir and tributaries: AA/AA
8. Padanaram Brook and tributaries north
of Padanaram Reservoir: AA/AA. Then Padanaram Brook from Margerie
Reservoir Brook south to Patch Street: B/A, and third Padanaram
Brook from Patch Street south to the Still River: B/B.
9. Saugatuck Reservoir tributaries reaching
north from Redding into Danbury: AA/AA.
10. Still River from Lake Kenosia easterly
to Padanaram Brook: B/A. Then the Still River from Padanaram
Brook easterly to Limekiln Brook: B/B. And next the Still
River from Limekiln Brook (where Danbury Sewer Treatment Plant
effluent enters) north to the Brookfield Line: C/B.
11. Sympaug Brook flowing from the Bethel
Line north to the Still River: B/B.
12. West Lake Reservoir and tributaries:
Unnamed brook in Rogers Park flowing south into Bethel
to join Reservoir Brook: B/A.
14. All other streams in Danbury such as
Great Plain Brook, Miry Brook, Parks Pond Brook, etc: A/A.