Date: Fri 13-Feb-1998

Publication: Bee

Author: ANDYG

Quick Words:

DOT-bridge-Stevenson

Full Text:

DOT Proposes $37.3 Million Bridge North Of The Stevenson Dam

BY ANDREW GOROSKO

The state Department of Transportation (DOT) is proposing the construction of

a new $37.3-million bridge across the Housatonic River to replace the

deteriorated span that carries Route 34 over the Stevenson Dam.

Construction of the proposed bridge is detailed in a draft federal

environmental assessment of the bridge's replacement prepared by DOT and the

Federal Highway Administration.

The report finds there would be "no significant environmental impact" in

connection with the bridge project which would link Monroe to Oxford by a

multi-span bridge almost 250 feet upriver of the existing Stevenson Dam

Bridge.

The Connecticut Light & Power Company (CL&P) owns Stevenson Dam and the bridge

atop it. DOT owns and maintains the "wearing surface" on the bridge. The

bridge is a basic element of the Stevenson hydroelectric power station which

generates electricity via the flow of the Housatonic River. Due to its

historical character and engineering design, the hydroelectric complex is

considered eligible for a listing on the National Register of Historic Places,

according to DOT.

DOT wants to replace the aging bridge to ensure the long-term safety and use

of the river crossing. It estimates the existing bridge's useful life

expectancy to be three to five years. "The substandard bridge and approach

road geometry... contribute to vehicular operational problems and appear to

contribute to frequent accidents," according to the draft report.

In reviewing how to improve the river crossing, DOT engineers considered eight

possible alternatives. These include:

Do nothing.

Rehabilitate the existing bridge.

Build a new bridge 1,804 feet upriver.

Build a multi-span bridge 246 feet upriver, which is the preferred

alternative.

Build a tied-arch bridge 328 feet upriver.

Reconstruct and replace the existing bridge on the dam with improved roadway

approach geometry.

Build a new bridge 984 feet downriver.

Build a new bridge 4,757 feet downriver.

The preferred multi-span bridge 246 feet upriver of the existing bridge, with

new approach roads tied into Route 34, would be approximately one mile long.

In reviewing the eight options, DOT engineers found that building a new bridge

4,757 feet downriver of Stevenson Dam would likely adversely affect wintering

bald eagles there, hurt overall wildlife habitat, and damage the area's scenic

value. Bald eagles winter in the area from mid-December to mid-March.

Similarly, building a bridge 984 feet dowriver of the dam is thought to

threaten the eagles, according to DOT.

Rehabilitating the bridge would be relatively costly and wouldn't improve

bridge safety or traffic flow, according to the report.

Building a new bridge on the dam would be very expensive, complicated and

require heavy maintenance after construction, according to DOT.

Building a bridge upriver of the dam is considering preferable by DOT because

it would have less impact on the eagles, according to DOT.

Of the three river bridge options, DOT engineers prefer constructing a new

bridge 246 upriver of Stevenson Dam because it is closer to Stevenson Dam than

the other upriver options and thus farther away from the section of the river

actively used for recreation, less intrusive to Monroe's boat ramp area, and

less visible from residential and recreational areas.

The preferred two-lane bridge would be designed for 37-mile-per-hour traffic.

The bridge would have road shoulders and a sidewalk. The $37.3-million

construction cost of the bridge does not include the cost of subsequently

removing the existing bridge atop the dam. Traffic would flow across the

existing bridge until a new span is open. DOT wants to have a new bridge in

service by the end of 2001. A new bridge would be designed to provide 50 years

of service.

According to DOT, the preferred alternative would have minimal long-term

effects on air quality, noise, vegetation, wildlife, threatened and endangered

species, wetlands, floodplains, residences, businesses and land uses.

Disturbing PCB's

The bridge construction project's disturbance of Housatonic River sediments,

which are contaminated with polychlorinated biphenyls (PCBs), could affect

river water quality and aquatic life, according to DOT.

The state Department of Environmental Protection (DEP) will gauge such water

pollution problems posed by bridge construction, according to the report.

"Because of the uncertain effects of `sediment resuspension' on aquatic life,

project-induced effects such as turbidity will be kept to a minimum and

environmental permit stipulations... will be closely followed," it adds.

The Housatonic River became contaminated with the colorless, odorless, toxic

PCBs after they entered the river at an electrical transformer factory run by

General Electric upriver in Pittsfield, Mass.

Although building the preferred bridge would require some land acquisition for

a new road right-of-way, no residential or commercial land uses would be

displaced, according to DOT.

The Route 34 bridge atop Stevenson Dam was built in 1919. The overall

condition of the narrow span is listed as poor.

The most recent major inspection of the bridge in April 1995 indicated heavy

rusting of steel beams, open cracks and hollow areas in cantilevers supporting

the bridge deck, cracks and spalls in the deck slab, deteriorated expansion

joints, frozen steel bearings, open cracks in concrete T-beams, and cracking

and spalling in the bridge's substructure. Stevenson Dam itself has been found

to be structurally sound by CL&P, according to DOT.

According to DOT, the Stevenson Dam Bridge's substandard width and approach

road geometry contributes to a high rate of sideswipes and fixed object

accidents. Pedestrian and bicycle movements are unsafe due to the lack of road

shoulders and a sidewalk. Sight distances are obstructed by a bridge railing.

Large tractor-trailer trucks have problems negotiating the tight curves at the

ends of the bridge.

From 1989 to 1994, 21 motor vehicle accidents occurred on the dam itself and

another 16 accidents took place within 1,050 feet of the dam.

Copies of the detailed draft report on bridge construction alternatives may be

reviewed by the public at the Monroe and Oxford public libraries and town

clerks' offices. Persons with comments on the report may submit them by March

2 to: Edgar T. Hurle, Director of Environmental Planning, Connecticut

Department of Transportation, 2800 Berlin Turnpike, PO Box 317546, Newington,

CT 06131-7546. DOT is expected to conduct a public hearing on the project.