[Ord. No. 54,
art. IV, § 1, eff. 9-12-1975]
Any proposed canal shall have a minimum width of 50 feet and
plans for any such canal shall be approved by the township board before
construction is commenced. Canals shall be designed to provide for
a canal bottom at an elevation of 568.0 (U.S. Geodetic Survey datum)
which is 4.2 below record low water.
[Ord. No. 54,
art. IV, § 2, eff. 9-12-1975]
No boat wells shall be constructed, installed or located closer
than 10 feet to a side lot line; excepting, however, this prohibition
shall not apply to boat wells of adjacent lots which abut at the common
side lot line. Notwithstanding the foregoing provision, the end walls
of a boat well installed or constructed parallel to the shoreline
shall not be located closer than three feet from the side lot line
where the end wall intersects the shoreline; and the end walls shall
angle in toward the boat well shoreline and each other intersecting
the boat well shoreline at not less than 135° nor more than 45°,
as the case may be. The township board may vary the provisions of
this section upon finding that strict compliance therewith will result
in practical difficulties by reason of the area, dimensions or configuration
of the lot involved. The following sketch depicts the requirements
of this article relative to parallel boat wells:
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[Ord. No. 54,
art. IV, § 3, eff. 9-12-1975]
Seawall construction for commercial or business property shall
be designed for the site by a registered professional engineer taking
into account all backfill weight as well as any surcharge weight due
to parking, buildings, etc.
[Ord. No. 54,
art. IV, § 4, eff. 9-12-1975]
Seawall construction for residential property shall be in accordance
with the following requirements:
(1)
Record high water elevation prior to 1974 was elevation 577.6 (all
elevations are based on the U.S. Geodetic Survey datum) based on conditions
of no wind or waves. Winds and waves can increase the lake level several
feet at the shoreline, lakes and canals depending on the direction
of the wind and other causes. The top of any seawall constructed under
this article shall not be less than elevation 580.0 which is 0.4 feet
above the record high water, unless 60% of the highest walls 300 feet
on either side of the proposed wall is less than such elevation then
and in that event the top elevation may conform to the medium elevation
of the highest 60% of the seawalls 300 feet on either side of the
proposed seawall. Depending on location and exposure the owner of
the proposed seawall should give consideration to the effects of wind
and waves in determining the need for additional height above that
elevation.
(3)
The stability of a seawall is dependent on the bottom section being
embedded in the ground to a sufficient extent to provide enough ground
resistance to prevent the bottom of the seawall sheeting from sliding
laterally. Sliding resistance is dependent on stiffness of the ground
and the amount of embeddment of the sheeting in the ground. The stiffer
the ground the less embeddment of the sheeting is required. Therefore,
walls shall have from 40% to 60% of their total length embedded in
the ground with the lesser figure being used for this stiffer or firmer
ground stratas and the greater figure being used for the soft clay
ground through which little effort is needed to drive the sheeting
during installation. Embeddment shall be defined as the part of the
total sheeting length driven in the ground below an elevation two
feet below the existing lake or canal bottom or below elevation 568.0,
whichever is higher.
(4)
Walls shall be complete with waler, capping, tie-backs and deadman.
(5)
Deadman shall consist of one section of steel sheet piling driven
vertically with a one-foot horizontal such that the bottom of the
piling is one foot closer to the wall than the top of the piling.
The top of the deadman pile shall be 3 1/2 feet below the top
of the wall. The deadman sheet piling shall be 10 feet long and located
not less than 16 feet back of the seawall, except that deadman sheet
piling installed on seawalls parallel to side lot lines may be a minimum
of 10 feet from the seawall but shall be increased in length one foot
for each foot less than 16 feet the spacing is between the deadman
and the seawall. No deadman shall be less than 10 feet from the seawall.
Deadman must be installed within the property on which the seawall
is installed.
(6)
Tie-backs connecting the waler and the deadman shall consist of not
less than three-quarter-inch diameter solid one-piece steel rods.
Tie-backs shall connect for the deadman sheet piling 3 1/2 feet
below the top of the deadman; however, a waler shall not be required
with steel sheeting, but a top cap shall be necessary with steel sheeting,
but a waler shall be required with all wood seawalls.
(7)
Deadman and tie-backs shall be spaced a maximum of eight feet center
to center.
(8)
Walers shall be installed 2 1/2 to 3 1/2 feet below the
top of the wall.
(9)
Design of the seawall shall take into account all backfill weight
as well as any surcharge due to parking, buildings and the like. However,
a minimum for a seawall length shall be 12 feet for canals and rivers
and 14 feet for lake construction for the total length of the sheeting.
