Current through Register Vol. 24-18, September 15, 2024
(1)
Description: A boat ramp or
launch is a sloping stabilized roadway or entry point constructed on the
shoreline for launching boats from vehicular trailers or by hand. Ramps and
launches extend into the water at a slope of typically twelve to fifteen
percent and are typically oriented perpendicular to the shoreline. Ramp and
launch widths vary with intended use, and the length often depends on the slope
of the shoreline and tidal amplitudes. Ramps and launches are usually
constructed in protected areas with access to deep water close to shore.
Construction materials commonly consist of gravel, concrete, or asphalt; they
are often associated with marinas and parking lots. A railway-type boat launch
consists of a pair of railroad tracks supported by pilings, and extends from
the upland down to the beach.
(2)
Fish life concerns: A boat ramp or launch covers seabed habitat
that supports fish life. A large number of ramps or launches in a given area
increases the amount of loss and fragments this habitat. Ramps and launches
placed above beach grade can block sediment movement (littoral drift). Ramp and
launch construction, maintenance and the associated vessel activity can damage
or destroy aquatic vegetation and forage fish spawning beds.
(3)
Boat ramp and launch design:
(a) The design and location of ramps and
launches must avoid adverse impacts to saltwater habitats of special concern.
(i) The department will require a
seagrass/macroalgae habitat survey for new ramp or launch construction unless
the department can determine the project will not impact sea-grass and kelp
beds and in herring spawning beds other macroalgae used as spawning
substrate.
(ii) A survey is not
required to replace an existing structure within its original
footprint.
(b) Design
and locate boat ramps and launches to avoid or minimize excavation waterward of
the OHWL.
(c) Design boat ramps and
launches to minimize impacts to tidal currents and littoral drift. Common
alternatives are ordered from least to most impacting:
(i) Elevated railway-type launches;
(ii) Hoist or lift launches;
(iii) Elevated ramps; and
(iv) Ramps constructed at beach
grade.
(d) The
department will authorize boat ramps and launches on marine accretion
shoreforms (such as barrier beaches, points, spits, and hooks) only if there
will be no impact to geomorphic processes that create and maintain nearshore
habitat.
(e) Design and construct
boat ramps and launches to prevent erosive undercutting or breaking of ramp
edges.
(f) Ramps elevated above the
beach grade must have side slopes no steeper than one and one-half feet
horizontal to one foot vertical.
(g) Design and locate new boat ramps and
launches to prevent the need for dredging. The department will allow dredging
to maintain access to an existing boat ramp or launch if the access was dredged
as part of the original project.
(h) Design boarding floats to minimize
grounding on and shading of the bed and impacts to tidal currents and littoral
drift.
(i) Use the smallest number
of pilings required to construct a safe railway-type launch.
(j) The rails of a rail launching system must
lie on and follow the grade of the existing bed and bank.
(4)
Ramp and launch
construction:
(a) Construct the ramp
or launch when the work area is not covered by tidal water.
(b) Construct footings or the base of the
ramp and launch below the preexisting beach grade of the beach to minimize
undermining of the structure.
(c)
To construct a concrete boat ramp waterward of the OHWL, use precast concrete
slabs or isolate the wet concrete from waters of the state until it is fully
hardened.
(d) Securely anchor
launching rails to the bed or support railway launch piling.
(5)
Ramp and hand launch
maintenance: Whenever feasible, place sediment and woody material
removed from ramps and launches at or waterward of the OHWL downdrift of the
structure.
