• Alex Shelton
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Waterbury Reservoir Risk Management Project

The dam at Waterbury Reservoir in Waterbury is situated on the Little River, about 2.5 miles above its confluence with the Winooski River. From Waterbury, the dam can be reached by traveling two miles west on U.S. Route 2, then right on Little River Road for three miles.

In conjunction with East Barre Dam and Wrightsville Reservoir, Waterbury Reservoir provides flood protection to the downstream communities of Duxbury, Bolton, Richmond, Williston, Jericho, Essex, Colchester, Burlington, South Burlington, and Winooski.

Construction of the project began in April 1935 and was completed in October 1938. The project consists of an earthfill dam with stone slope protection 1,845 feet long and 187 feet high; an 882-foot-long semicircular concrete conduit 10.5 feet high and 14 feet wide; two 230-foot-long steel conduits, each with a diameter of four feet six inches; a 290-foot-long steel circular conduit with a diameter of four feet; three 26.5-foot-high tainter gates, with two gates each measuring 20 feet wide and the third 35 feet wide; and a spillway cut in rock with a 154-foot-long concrete ogee weir. The weir’s crest elevation is 15.5 feet lower than the top of the dam. Waterbury Reservoir was one of four flood damage reduction projects constructed in Vermont by the Civilian Conservation Corps (CCC) in the 1930s. Construction was overseen by the Corps’ North Atlantic Division. Because of accounting procedures, the construction costs of Waterbury Reservoir were not calculated separately, but instead lumped together with the construction costs of East Barre Dam, Wrightsville Reservoir, and the Winooski River Local Protection Project. The construction costs of these four projects totaled $13.7 million. Following completion, Waterbury Reservoir and associated lands were turned over to the state of Vermont for operation and maintenance.

The present-day configuration of the dam is the result of two major modifications that allow a greater amount of water to pass through the spillway, increasing the dam’s structural integrity. The first modification, which began in September 1956, included raising the dam three feet and installing the 35-foot-wide tainter gate. This work was completed in November 1959 at a cost of $861,000. The second modification began in January 1985 and involved constructing the 290-foot-long steel conduit, rebuilding the toe of the dam, and grouting the dam’s foundation to control seepage. This work was completed in December 1985 at a cost of $4.8 million.

For most of the year, Waterbury Reservoir has a pool of 860 acres with a maximum depth of approximately 100 feet. During the winter, the pool is drained to a surface area of between 250-300 acres by the Green Mountain Power Corporation, owners of the hydroelectric power plant at the base of the dam (see below), in anticipation of spring rains and snowmelt. The flood storage area of the project, which is normally empty and utilized only to store floodwaters, totals 1,330 acres and extends approximately six miles upstream through Stowe. The project and all associated lands (including part of Mount Mansfield State Forest) cover 12,912 acres. Waterbury Reservoir can store up to nine billion gallons of water for flood control purposes. This is equivalent to 4.8 inches of water covering its drainage area of 109 square miles.

The main recreational attraction at Waterbury Reservoir is the Little River State Park, a 1,100-acre block within the larger 37,000-acre Mount Mansfield State Forest. Little River State Park has a 60-acre campground on the western shore of the reservoir containing 101 campsites (20 of these sites have lean-tos), each with its own picnic table and fireplace. There are two designated swimming areas: Area A has about 300 feet of beach situated on one side of Stevenson’s Brook Cove, and Area B, located approximately 650 feet across the cove, has about 150 feet of beach. Little River State Park also has an excellent marked trail system, with dozens of hiking trails totaling about 30 miles. During the winter, about 17 miles of trail are marked for snowmobiling, with the remainder marked for cross-country skiing. The campground has a boat ramp (located in Area A); boat rentals; hot showers; drinking water; and sanitary facilities.

History buffs take note: There are three areas of archeological and historical significance within the Little River State Park. They are:

• The Civilian Conservation Corps campsite used by the workers constructing the dam at Waterbury Reservoir. Between 1933 and 1939 over 2,000 men lived and worked here. At one time, this self contained community featured more than 80 buildings. Although a few foundations exist, none of the buildings remain. This area is located on Little River Road, about .25 mile southwest of the dam.
• The foundations of a farm community dating back to the late 1800s. This site is situated about 2.5 miles northwest of Stevenson’s Brook Cove.
• Several foundations of farmhouses dating back to the late 1700s. These are located near Cotton Brook, about eight miles north of dam. Note that the final six miles of travel must be made through woods; this site is not directly accessible by car.

Another recreational area enjoyed by visitors to Waterbury Reservoir is the Waterbury Reservoir Day Use Recreation Area, a 90-acre peninsula situated on Town Highway 17 (Old River Road), about .25 mile off Route 100. This site offers picnicking on 12 tables and 10 charcoal grills; swimming on 220 feet of beach; a concrete boat ramp; snowmobiling and cross-country skiing on unmarked trails; and sanitary facilities.

Three other areas offer limited recreational opportunities. The Waterbury Reservoir Boat Launch Area is located immediately behind the dam and provides boaters with an area in which to unload. The Blush Hill Recreation Area, located on Route 100 about six miles north of the dam, offers snowmobiling on marked trails. The Little River Canoe Access Area, located on Moscow Road (off Route 100) about five miles north of the dam, allows canoeists easy access to the reservoir. All of the above-mentioned recreational areas are operated and maintained by the Vermont Department of Forests, Parks, and Recreation, except for the Waterbury Reservoir Boat Launch Area, which is operated and maintained by the Vermont Department of Environmental Conservation.

There is fishing throughout the reservoir area. The state stocks rainbow and brown trout, and the reservoir contain self-sustaining smallmouth bass, yellow perch, brown bullhead, fallfish, golden shiners, pumpkinseed, white suckers, and long nose suckers. The state has also introduced smelt eggs to the Little River. Ice fishing is permitted. There is in-season hunting for native deer, ruffed grouse, and gray squirrel.

In June 1953, private interests completed the construction of a hydroelectric power plant situated at the base of the dam. This facility, the Little River Hydro Station, generates approximately 5.5 megawatts of power, which is used by the Green Mountain Power Corporation.

• Alex Shelton
• My Blog

WATERBURY CENTER STATE PARK AND WATERBURY RESERVOIR

Lake Area:

860 acres

Lake Max. Depth:

100 feet

Fish Species

Rainbow trout, brown trout, rainbow smelt, smallmouth bass, bullhead, and yellow perch.

Habitat

When the Little River was dammed, it created the Waterbury Reservoir. Little River flows into the reservoir at its north end and out of the reservoir via controlled flow at its southern end. The reservoir features clear water and a bottom consisting of a mix of sand, silt, gravel, boulders and ledge.

Quality fish habitat ranges from submerged trees and brush, to rocky points, bluff walls, gravel banks and some aquatic vegetation.

Park Fishing Tips

Waterbury Reservoir provides anglers with the opportunity to fish diverse fish-holding habitat including submerged woody cover, rocky points, bluff walls and some aquatic vegetation. Fallen trees cover a wide range of depths and will produce fish during all open water months.

A good portion of the reservoir’s shoreline consists of steep rock walls that can be very productive for smallmouth bass during the warmest months. Fish these walls with unweighted soft plastic lures and suspending jerk baits. If you are looking for a rush, get out in the early morning and enjoy a fantastic top water bite! While fishing with these tactics, anglers may also hook into some nice yellow perch, rainbow trout and brown trout.

Shoreline fishing opportunities abound at Waterbury Center State Park and via various trails around the reservoir. Wild brook trout and rainbow trout can also be found in Stevenson Brook, which flows through Little River State Park on the southern end of the reservoir.  Or you can take a canoe, kayak or motorboat to any fishing spots on your radar! 

Nearby Fishing License Dealers

You can purchase a fishing license at Parro’s Gun Shop in Waterbury, The Fly Rod Shop in Stowe, or online.

Nearby Boating Access Areas

Various boat launches are available on Waterbury Reservoir, including launching areas at Little River State Park, Waterbury Reservoir State Park, and adjacent to the Waterbury Reservoir dam.

• Alex Shelton
• My Blog

Man-made Reservoirs

Man-made reservoirs, sometimes called artificial lakes, are important water sources in many countries around the world. In contrast to natural processes of lake formation, reservoirs are artificial, usually formed by constructing a dam across a river or by diverting a part of the river flow and storing the water in a reservoir. Upon completion of the dam, the river pools behind the dam and fills the artificially created basin (UNEP 2000). Seasonal changes of runoff and precipitation feed the reservoir. There are big differences in the size of man-made reservoirs such as big artificial lakes or small pond-like waterbodies. The stored water can be used for irrigation, drinking water after purification, or to produce energy.

Introduction

A reservoir is an artificial lake called a man-made reservoir. It can be formed by building a dam across a valley, by excavating the land, or by surrounding a piece of land with dykes and diverting a part of the river flow into the reservoir. The water is stored in the reservoir and can be used for irrigation, hydro-power, or as a water source for domestic or industrial use. Man-made reservoirs are also very effective constructions to control unexpected floods (see also stormwater management). A reservoir is fed by precipitation, rainwater runoff, or a constant flow of a river. Water loss can occur due to evaporation (especially in arid regions) and depending on the reservoir bottom due to percolation (small reservoirs are often linked). Sediments from rivers or surface runoff can reduce the storage volume of a man-made reservoir significantly (FAO 1992).

Water stored in a valley usually has a higher level than the valley bottom downstream of the dam. Because of this difference in level, the valley can be irrigated by a gravity system or other distribution systems. Water can be taken from the reservoir via a concrete or steel pipe. This pipe connects the reservoir to an irrigation canal downstream. A valve is usually located on the upstream end of the pipe to control the discharge of water into the canal (FAO 1992). The kinetic energy of reservoirs is often used to produce electricity (see also hydropower small-scale and hydropower large-scale).

Ecological Impacts

Where no such water body previously existed the presence of a reservoir in a drainage basin and the abstraction of significant water amounts for storage upstream significantly impacts the watercourse, the flora and fauna, and the human inhabitants in the drainage basin. These potential impacts should be identified and thoroughly examined prior to reservoir construction, in order to comprehensively assess the total value of the reservoir project. Procedures to identify and properly evaluate potential environmental, social, and economic consequences of reservoir construction involve the so-called ‘Environmental Impact Assessment’ (EIA). Such an assessment is now obligatory by law in many countries for all new dam constructions (UNEP 2000).

Ecological impacts of reservoir dams have been reported from various aspects such as barrier for migratory animals like anadromous fish, eutrophication of reservoirs by plankton blooming, decreasing flow volumes in tailwaters, stabilization of flow regimes by flood peak cut, changes in thermal regimes of river water, river bed degradation and increase in substrate grain size by sediment trapping, etc. (TAKEMON 2006). Furthermore, big dams and the extraction of water (e.g. for spate irrigation) can create riparian conflicts (see water conflicts). Also, read the paragraph “Impact on Environment” in the rivers factsheet.

Basic Design Principles

Factsheet Block Body

Adapted from UNEP (2000)

Like lakes, reservoirs range in size from pond-like to very large water bodies (e.g. Lake Powell, U.S.A.). The variations in type and shape, however, are much greater than for lakes. The term ‘reservoir’ includes several types of constructed water bodies and/or water storage facilities:

• Valley reservoirs – created by constructing a barrier (dam) perpendicular to a flowing river.
• Off-river storage reservoirs – created by constructing an enclosure parallel to a river, and subsequently supplying it with water either by gravity or by pumping from the river.

The latter reservoirs are sometimes called embankment or bounded reservoirs and have controlled inflows and outflows to and from one or more rivers. In addition to single reservoirs, reservoir systems also exist and include cascade reservoirs – consisting of a series of reservoirs constructed along a single river, and inter-basin transfer schemes – designed to move water through a series of reservoirs, tunnels, and/or canals from one drainage basin to another.

Pumping from a Reservoir for Irrigation

Adapted from FAO (1992)

The fields located around the reservoir upstream of a dam or surrounding a natural lake are higher than the reservoir or lake’s water table. Here irrigation is only possible with the help of pumping stations, manual or motorized pumping.

The water level in the reservoir is usually highest at the end of the rainy season, and lowest at the end of the dry season or the irrigation season. Pumps installed at reservoirs and lakes must be able to handle these fluctuations, which are not only vertical but even more pronounced horizontally because the water recedes back to the lowest parts of the reservoir. A dead branch of a river can also be made to function as a reservoir. The branch is filled with water during the wet season and closed off during the dry season so that the stored water may be used. Due to the low water level, pumps are normally needed to irrigate fields from such a reservoir.

Costs

Factsheet Block Body

Especially for large reservoirs costs are high. It must be designed by engineers and heavy machinery is necessary. Furthermore, costs for material as well as O&M should be considered. If it is constructed for a hydropower water source costs are even higher because much more technical equipment, as well as operation and maintenance, is needed.

Operation and Maintenance

Factsheet Block Body

Because reservoirs are man-made water bodies, they are more amenable to artificial operation and regulation than lakes. As previously noted, operational possibilities unique to reservoirs include the ability to discharge known volumes of water at predetermined times, and selective discharge of water from different water layers within the reservoir. This must be planned carefully as it directly impacts the environment as described above. Also, read the document “Reservoir Operations and Managed Flows” (WMO and GWP 2008).

Dams, especially the very large ones, must be checked regularly to ensure their stability and security. Furthermore, many man-made water reservoirs are affected by high sedimentation rates. The accumulation of sediments in the reservoir reduces the main reservoir asset i.e. its volume capacity. Moreover, sediments can negatively affect pumping and hydropower equipment. Therefore the designers should consider soil erosion and sediment transport (CHANSON and JAMES 1998). There are several approaches to minimize or deal with sedimentation.

When a reservoir serves different functions it is nearly impossible to operate each function at its maximum level. For example, a reservoir that provides irrigation, power generation (see small scale and large scale hydropower), flood control, and recreational use may cause conflicting demands by its users (WATERENCYCLOPEDIA 2011).

Health Aspects

Factsheet Block Body

Faecal pollution and other contamination of reservoirs have to be prevented by wastewater treatment and buffer zones in case of non-point sources of pollution (see also the factsheets on lakes or water sources and well protection). If the reservoir is also used as a source of drinking water, please also check water purification as a measure to protect human health.

It should also be considered, that surface water sources can lead to mosquito breeding. Applicability

Water from a reservoir as a surface water source is applicable for use for irrigation in agriculture, households, or processing in industries. Depending on the size of the reservoir, impacts (ecological, riparian) must be considered to avoid contamination, damage to the environment or user conflicts.