Analysis and Ranking of the Acoustic Disturbance Potential of ...

Report No. 6945
BBN Systems and Technologies Corporation
nearby Kenai airport. The south threshold of the runway is located just north
of the river, and arriving and departing aircraft often pass directly over the
water at an altitude of 150-300 m (500-1,000 ft).
3) Kachemak Bay: Kachemak Bay has a relatively high level of local boat
traffic originating from Homer and the nearby fishing village of Kachemak Selo
at the mouth of Swift River. Boat traffic includes a variety of dieselpowered
commercial crab and salmon fishing vessels, and inboard and outboardpowered
pleasure craft and sport-fishing boats (ranging from small skiffs to
high-speed cabin cruisers and occasional air-boats).
Air traffic includes near-weekly U.S. Coast Guard Hercules C-130's flying
below about 300 m (1,000 ft) and occasionally below about 150 m (500 ft) over
the bay; one (often two) National Guard Bell UH-1 helicopters flying below 300
m (1,000 ft) and often below 150 m (500 ft) along the shores of the bay about
once (sometimes two to three) times per week; numerous scheduled daily passenger
aircraft (e.gl, DHC Twin Otters, Piper Navahos, Cessna 402's, Beechcraft
18's, twin-engine Convairs) that often fly below about 300-600 m ( 1,000-2,000
ft) along or over the bay; and numerous private, charter and air taxi singleengine
fixed-wing and light helicopter aircraft flying low over or along the
shores of the bay (e.g., Cessna 185's, 206's, 207's; Piper Super Cubs; Bell
206B Jet Rangers).
During late June 1986 - early June 1987, construction activities for the
Bradley Lake Hydroelectric Project along tideline on the east shore of the
upper bay included construction of a temporary 200 man camp; construction of
dock facilities and some channel dredging at Sheep Point. This involved
considerable barge traffic and unloading of heavy equipment and supplies at
the Martin River delta (summer 1986.) and Sheep Point dock (late summer 1986 -
spring 1987). Construction of about 9.5 km (6 mi) of road at tideline between
the Martin River and a point about 3.2 km (2 mi) north of Sheep Point
( included blasting at Sheep Point and the future powerhouse site about 3.2 km
(2 mi) north of Sheep Point). There was also considerable large-scale blasting
at a hillside quarry site about 1.6 km (1 mi) from the bay (including loud
double and triple explosions that frequently echoed across the bay during
July - August 1986). Demobilization of some camp facilities involving barge
traffic occurred during April-June 1987.
5.1.10 Gulf of Alaska -
The major noise sources in the Gulf of Alaska region are associated with
the tanker traffic servicing the pipeline terminal in Valdez and the cruise
ship activity in Southeast Alaska. Secondary sources are general fishing
activity and ship traffic in the gulf and aircraft operations near airports
and along beaches. The tanker traffic contribution is greatest in Prince
William Sound where traffic lanes are more restricted than they are offshore.
The noise contributions from smaller cargo vessels, cruise ships, and ferry
traffic are also significant.
Cruise ship traffic in Southeast Alaska has been increasing in recent
years. The major routes for these ships run from the Dixon Entrance up to
Juneau through Stephens Passage and then through the Lynn Canal to Skagway and