PND Engineering Reports
Herring Cove Marina
PN&D Engineering Report – Herring Cove Marina
Herring Cove is a naturally protected water body on Silver Bay. It is accessible and has adequate depth for a boat moorage basin. It protrudes eastward from the eastern boundary of Silver Bay and is protected from prevailing southeasterly winds by Bear Mountain. Two small islands to the west of Herring Cove provide protection from winds and waves produced in Eastern Channel. The hills between Herring Cove, Beaver Lake and Blue Lake provide protection from northeasterly and easterly winds. Herring Cove is accessible via the existing public road system via Sawmill Creek Road. [Sawmill Creek road is presently undergoing a $6 million upgrade.] It has depths over ten fathoms over most of the protected body of Herring Cove.
A conceptual design of a boat
marina was developed. The marina layout is divided into three
phases of development. The first phase includes uplands parking
and access development, channel markers at the entrance to Herring
Cove, two access trestles and gangways leading to a head float
and three main floats with sixty-six, 60-foot moorage stalls.
Upland development includes a harbor office, public restrooms,
and space for trash receptacles, waste oil containers and parking.
The layout is adjacent to a double wide boat launch with trailer
parking. [Developer may choose to not install a boat ramp and
trailer parking.] The second phase of development includes extension
of three main floats and the addition of seventy-four 60-foot
moorage stalls. The third phase includes extension of the head
float and an additional main float with thirty-eight additional
60-foot moorage stalls.
The layout with 60-foot slips was developed to address the need
for additional moorage for larger boats with utilities and security.
Access trestles or gangways can be gated with security locks
so that unauthorized personnel are not allowed on the floats.
Utilities would include water, electrical power, cable TV, communication
and sewage pump-out stations. Individual moorage stalls could
be covered if desired.
All steel piles in the marina should be galvanized. Floats should
be either of treated timber or of high-performance concrete
surrounding rigid insulation floatation units.
Herring Cove has several issues that would need to be dealt
with: unmarked entrance and wood and bark accumulation on the
bottom. There are several rock pinnacles and mounds at the entrance
of the cove that are potential hazards to navigation. The passage
should be marked with channel markers or lights to ensure safe
passage in and out of the cove. The minimum width of the entrance
with 60-foot depth below Mean Lower water (MLLW) is approximately
75 feet. Channel markers must be included in any boat marina
development. Wood and bark accumulation may make pile driving
difficult and complicate the permitting process.
Although some information about the sea floor is available from
dive surveys, existing sea floor sub-bottom and pile driving
conditions are not known. At this stage of development, it is
conservative to assume that piles would have to be socketed
or anchored into bedrock.
Permits Required
Permits required for this development include a Department of
the Army (DA) Section 404 permit, an Alaska Department of Environment
Conservation Clean Water Certificate, an Alaska Coastal Zone
Management Consistency Determination. In addition to state and
federal permits, a tideland lease from the Alaska Department
of Natural Resources will be necessary as will a City of Sitka
Building Permit.
The Alaska Department of Environmental Conservation (ADEC) has
listed Herring Cove as an impaired Water Body because of wood
and bark accumulation from previous log raft storage. ADEC regulations
require such a status if any bark or wood has accumulated on
the sea floor. Although Herring Cove was on the list of impaired
water bodies, construction of a marina there is possible form
a permitting point of view. Some form of economic or physical
mitigation may be required when permitting the project. Mitigation
may take the form of creating conservation reserve land or contributing
to a conservation fund
Utility Services
Utility services would have to be extended to Herring Cove.
Electrical and water service would have to come one mile. Sewage
service would necessitate either a septic system or small treatment
plant that could eventually be discharged into Silver Bay beyond
the opening to Herring Cove.
Costs
The rough order magnitude cost for the construction of phase
1 of Herring Cove Marina is estimated to be $6.02 million, which
includes contingencies, design and other pre-construction and
indirect costs [does not include costs to extend utility
services]. Phase Two is projected to cost $2.74 million
and Phase Three construction costs are estimated to be $1.45
million. (2002 Costs)
PN&D Engineering Report – Cove Island
The island(s) protecting Herring Cove from Silver Bay
could be developed as a lodge with floats on Herring Cove. This
development could serve as a base for the marina and/or a charter
fishing operation.
Construction
Two islands separate the body of Herring Cove from Silver Bay.
The first island is very small and separated by a small waterway
from Baranof Island. The second and larger island [approximately
3 acres] may be suitable for a resort or vacation lodge.
Access to the second island from the main land could be possible
by building a road and bridge to the island from Sawmill Creek
Road [main access highway from downtown Sitka]. Road
construction would include clearing and grubbing the route and
a large fill section. The small waterway between Cove Island
and the main land [Baranof Island upon which Sitka is located] could be bridged by an open bottom arch culvert. To enhance
the resort, a moorage float accessed by a gangway could be built
within Herring Cove to accommodate boats.
Permits Required
Permits required for the development of Cove Island include
a Department of the Army (DA) Section 404 permit, a US Coast
Guard Bridge Permit, an Alaska Department of Environmental Conservation,
an Alaska Coastal Zone Management Consistency Determination,
a tidelands lease from the Alaska Department of Natural Resources
and a City of Sitka Construction Permit.
Utility Services
Utility services would have to be extended to Cove Island.
Electrical and water service would have to come one mile. Sewage
service would necessitate either a septic system or small treatment
plant that would eventually be discharged into Silver Bay beyond
the opening to Herring Cove.
Costs
Rough order magnitude construction costs for island access and
the float are estimated to be $1.13 million, which includes
contingencies, design and other pre-construction and indirect
costs [does not include costs to extend utility services].
These costs do not include costs for lodge construction or lodge
site development costs. [The island may be leased or purchased
from the City of Sitka]
