It shall be the responsibility of the owner of any lot or parcel of land developed for any use, other than those listed in § 155.034, to obtain an improvement location permit from the office of the Zoning Administrator. If the site has significant potential for drainage and erosion problems as determined by the Administrator, or in consultation with the County Soil and Water Conservation District representative, then the issuance of this permit shall include the review and approval of a drainage and/or erosion control plan, as specified in this section, unless provision for drainage and erosion control has been handled under the Subdivision Control Ordinance.
(A) If required, an erosion control plan must be submitted as a part of an improvement location permit application. In addition to the information required herein, an erosion control plan must be submitted detailing measures to be implemented during and after construction on a form provided by the Zoning Administrator, or County Soil and Water Conservation District and approved by the Soil and Water Conservation District.
(B) All general development must comply with 327 I.A.C. 15-5-2. In addition, a notice of intent must be submitted and a permit received from the State Department of Environmental Management prior to issuance of an improvement location permit, if one of the following applies:
(1) If an individual home construction will disturb five acres or more;
(2) If commercial or industrial construction will disturb one acre or more based upon a lot size of one acre or more; or
(3) All strip development, unless the total combined disturbance on all individual lots, is less than one acre and is not part of a larger common plan of development and sale.
(C) Land to be developed shall be designed and improved as far as practical in conformity to existing topography in order to minimize stormwater runoff, and conserve the natural cover and soil. Whenever possible, existing natural surface drainage may be utilized. To the maximum extent, there shall be no increased peak discharge or runoff rates as a result of the development unless downstream systems are sufficient to accept the discharge.
(D) Whenever the evidence available indicates that the natural surface drainage is inadequate, the owner shall provide the parcel with an adequate surface water system which shall be integrated into the drainage pattern of surrounding properties. When additional surface drainage is required, adequate easement for such drainage shall be provided.
(E) On site detention storage of stormwater shall be required where necessary as determined by the Administrator, or in conjunction with a County Soil Conservation District representative in order to prevent damage to adjoining properties.
(F) As required, a drainage plan must be submitted as a part of an improvement location permit. In addition to the information required herein, the Drainage Plan must include the following information:
(1) Existing and proposed grading showing positive drainage by contouring or sufficient spot elevations;
(2) Location of all existing or proposed swales, ditches, culverts, drainage channels, surface and subsurface drainage devices, and the direction of flow;
(3) Illustration of the surface drainage pattern of the site away from structures;
(4) Final distribution of surface water off-site, either preventing or planning for surface ponding;
(5) Demonstration of capability of accommodating the ten-year design rainfall intensity, or a rainfall of greater intensity, without endangering the public safety and health, or causing significant damage to property;
(6) A certificate of sufficiency that resembles the format as shown on the following page shall be submitted along with the plans; and
(7) Detention storage facilities, if required, shall submit the following additional information:
(a) Plans for storage of and a controlled release rate of excess stormwater with adequate detention storage to ensure that the release rate of stormwater following and during developments, redevelopments, and new construction shall not exceed the stormwater runoff from the land in its present state of development (present state of development means state of development as of January 1, 1993); and
(b) Detailed computations to show that peak rate following and during construction shall not exceed the stormwater runoff rate in its present state of development.
1. The computations must indicate that runoff will not be increased and must include computations of runoff before and after development.
2. The computations must demonstrate that the peak runoff rate after development for the 100-year return storm of critical duration will not exceed the ten-year period predevelopment peak runoff rate.
3. The critical duration storm is that storm duration that requires the greatest detention storage.
(G) (1) Drainage swales (ditches) along dedicated roadways and within the right-of-way or on dedicated drainage easements are not to be altered, except for maintenance, as originally constructed and as approved by the County Highway Department.
(2) Driveways or other approved structures may be constructed over these as permitted by the County Highway Department, with adequate provision for the flow of surface drainage.
(H) No permanent structures other than a fence may be erected, and, if erected in violation of this section, no such structure may be used if the location is within 75 feet of the center line of any legal tile ditch, or within 75 feet of the existing top edge of any legal open ditch or as determined by the County Surveyor.
(I) No cut or fill grade shall exceed a slope of three to one ratio or 33-1/3%. This provision shall apply to all cuts and fills exceeding 100 square feet in exposed surface areas, including cuts or fills on land naturally exceeding a three to one ratio in slope.
(J) (1) All lands, regardless of their slope, from which structures, or natural cover have been removed or otherwise destroyed, shall be appropriately graded or seeded within a reasonable time of such activity.
(2) The phrase “a reasonable time” shall be interpreted to be within two weeks during the growing season and shall be rigidly applied to construction activities in order to accomplish the intent of keeping erosion to an absolute minimum.
(3) Temporary vegetation or mulching shall be used to protect exposed areas during development.
(K) All drainage and erosion control systems must be safe to persons and maintained at all times. All land disturbing activities on site should be conducted in a logical sequence so that the smallest practical area of land will be exposed for the shortest practical period of time.
(Prior Code, § 153.037) (Ord. 93-02, passed 2-1-1993; Ord. 2009-19, passed 12-7-2009)