(A) Applicability. Where a subdivision is traversed by a watercourse, drainageway, natural channel, or stream, an easement or right-of-way shall be indicated on the subdivision plat or site plan that conforms substantially to the limit of such watercourse, plus additional width required by the applicable storm water management facility.
(B) Natural watercourses or floodplains.
(1) Easements for natural watercourses shall be the 100-year floodplain or the 25-year, plus freeboard.
(2) A driveable accessway shall be provided in floodplain easements for the length of the easement when regular maintenance of the floodplain is required.
(C) Maintenance access right-of-way.
(1) An unobstructed access right-of-way connecting the drainage easement with an alley or roadway parallel to or near the easement shall be provided at a minimum spacing of one access right-of-way at approximately 1,000-foot intervals.
(2) The access right-of-way shall be a minimum of 15 feet in width and shall be maintained clear of obstructions that limit maintenance vehicle access.
(3) If the flow line of the designed channel incorporates grade control structures or vehicular bridges that prevent maintenance equipment from accessing that portion of the channel, additional access points may be required.
(4) Channel design, earthen or concrete, shall have ramps in the side slopes near the access points that allow maintenance equipment to descend to the floor level of the channel.
(5) The maximum allowable ramp slope for vehicular access is 7:1.
(D) Lot and property line crossings.
(1) Where drainage easements cross lot and property lines, a statement shall be added to the plat that no fencing or structures that will interfere with drainage flow are permitted on or across such lines.
(2) Fencing may be allowed across drainage easements only in accordance with the following restrictions:
(a) The bottom of the fence shall be a minimum of the flow depth, plus freeboard above the design flow line of channel or drain; and
(b) Fence posts located within the easement must be structurally designed to resist damage from the stormwater flows and impact from debris.
(E) Interceptor easements. Interceptor drainage easements and channels shall be provided where the drainage area to the back of platted lots exceeds the depth of two average residential lots. Interceptor drains shall be constructed prior to the issuance of development approvals on any lot that is affected by the intercepted natural drainage being intercepted.
(Ord. 3020, passed 9-10-2013, § 5.22.8)