(A) (1) Watercourse relocation or modification is generally not permitted because these activities are not usually consistent with the purposes of §§ 160.087 through 160.100 of this chapter. Under certain circumstances, relocation and minor modification may be permitted through a site development permit where certain problems can be mitigated by relocation and/or minor modification, specifically when:
(a) Off-site hydrologic conditions are causing erosion, flooding and related problems;
(b) On-site soil and geologic conditions are resulting in unstable conditions that pose hazards to life, health, and existing structures or property;
(c) The quality of previously modified or relocated streams can be improved through restoration;
(d) Officially adopted stormwater management plans call for placement of detention or retention facilities in a stream; or
(e) Public utilities, including sanitary sewers, pipelines, and roadways require stream crossing or relocation where there are not practical alternatives.
(2) Modification of watercourses as a convenience for site design purposes is not permitted.
(B) (1) Conditions and restrictions for permitting stream modification. Stream modification, when permitted, is subject to the following conditions and restrictions:
(a) Water quality, habitat and other natural functions must be significantly improved by the modification; no significant habitat area may be destroyed;
(b) The amount of flow and velocity of a stream is not to be increased or decreased as the stream enters or leaves a subject property, unless this reflects an improvement over previous conditions in terms of reduced flooding, reduced erosion, or enhanced low flow conditions;
(c) Prior to diverting water into a new channel, a qualified professional approved by the village shall inspect the stream modification, and issue a written report to the village that the modified stream complies with the requirements in division (B)(2) of this section; and
(d) Stream channel enlargement, or other modifications that would increase conveyance, shall not be permitted if the intended purpose is to accommodate development activities in the floodplain.
(2) Required content of stream modification, relocation plan. Stream relocation may be permitted in accordance with a stream relocation plan that provides for:
(a) The creation of a natural meander pattern, pools, riffles, and substrate;
(b) The formation of gentle side slopes (at least three feet horizontally per one foot vertically), including installation of erosion control features;
(c) The utilization of natural materials wherever possible;
(d) The planting of vegetation normally associated with streams, including primarily native riparian vegetation;
(e) The creation of spawning and nesting areas wherever appropriate;
(f) The re-establishment of the fish population wherever appropriate;
(g) The restoration of water flow characteristics compatible with fish habitat areas, wherever appropriate;
(h) The filling and revegetation of the prior channel;
(i) A proposed phasing plan, specifying time of year for all project phases;
(j) Plans for sediment and erosion control; and
(k) Establishment of a low-flow channel that reflects the conditions of a natural stream.
(3) Criteria for permitting armoring of channels and banks. Armoring in the form of bulkheads, riprap or other materials or devices is not permitted except in accordance with the following:
(a) Significant erosion cannot be prevented in any other way and the use of vegetation and gradual bank slopes has not sufficiently stabilized the shoreline or bank;
(b) The bulkhead or other device is not placed within a wetland, or between a wetland and a lake or pond;
(c) The bulkhead, riprap or other device will minimize the transmittal of wave energy or currents to other properties; and
(d) The change in the horizontal or vertical, configuration of the land must be kept to a minimum. Where permission to install bulkheads or other armoring devices is requested as part of the site development permit application documentation and certification pertaining to the items above must be submitted.
(4) Criteria for permitting the use of culverts. Culverts are not permitted in streams except in accordance with the following:
(a) Where a culvert is necessary for creating access to a property; use of culverts as a convenience, in order to facilitate general site design, is not to be considered;
(b) The culvert must allow passage of fish inhabiting the stream, and accommodate the 100-year flood event without increasing upstream flooding, except where a restricting culvert is desirable as part of an overall storm and floodwater management plan;
(c) The culvert must be maintained free of debris and sediment to allow free passage of water, and if applicable, fish; and
(d) The stream bottom should not be significantly widened for the placement of a culvert as this increases siltation; if multiple culverts must be installed, one culvert should be at the level of the bottom of the stream and the others at or above normal water elevation.
(5) Criteria for permitting on-stream impoundments. Impoundment of streams is not permitted except in accordance with the following:
(a) The impoundment is determined to be in the public interest by providing regional stormwater detention, flood control, or public recreation;
(b) The impoundment will not prevent the upstream migration of indigenous fish species;
(c) A non-point source control plan has been implemented in the upstream watershed to control the effects of sediment runoff as well as minimize the input of nutrients, oil and grease, metals, and other pollutants;
(d) Impoundments without permanent low-flow pools are preferred except where a permanent pool is necessary to achieve the intended benefits of the impoundment (e.g. recreation or water quality mitigation); and
(e) Impoundment design shall include gradual bank slopes, appropriate bank stabilization measures, and a pre-sedimentation basin.
(Ord. 06-0383, passed 3-15-06)