§ 156.025 DRAINAGE PLAN SUBMITTALS.
   Each applicant shall submit the following information to ensure that the provisions of this chapter are met. The submittal shall include sufficient information to evaluate the environmental characteristics of the property, the potential adverse impacts and benefits of the development on water resources both on-site and off-site, and the effectiveness of the proposed drainage plan in managing stormwater runoff, and meet the provisions of § 156.002. The applicant's “Engineer's Hydraulic/Hydrologic Drainage Summary and Certification” shall include the following information submitted for both existing and proposed property conditions for all new development or redevelopment:
   (A)   Topographic mapping. A topographic survey of the property at two-foot contours unless otherwise specified or approved by the city. If the mapping is compiled using a digital format (CAD) and the global positioning system (GPS), the applicant will provide both paper and digital copies including CAD drawings and GPS points.
   (B)   Aerial mapping. An aerial photograph of the property including all off-site areas that contribute drainage to the site.
   (C)   Site drainage plan. A plan showing existing drainage and proposed drainage for the property and 100 feet surrounding the property at a scale of not more than 100 feet to one inch and including the following:
      (1)   Title, scale, north arrow, legend, seal of licensed professional engineer, date and name of person preparing plans;
      (2)   A vicinity map showing the relationship of the site to its general surroundings at a scale of not less than 2,000 feet to one inch;
      (3)   Property boundary, dimension and approximate acreage;
      (4)   Building setback lines;
      (5)   All existing or proposed easements;
      (6)   All existing and proposed structures and sizes;
      (7)   Roads, streets and associated stormwater inlets including finished grades;
      (8)   All existing, abandoned or proposed water main or monitoring wellhead locations;
      (9)   All sanitary or combined sewer lines, septic systems and aeration systems;
      (10)   Banks and centerline of streams and channels;
      (11)   Shoreline of lakes, ponds and detention basins with normal water level elevation;
      (12)   Known farm drains and tiles;
      (13)   Location, size and slope of stormwater pipes and drainage swales;
      (14)   Depressional storage areas;
      (15)   Detention and/or retention facilities;
      (16)   Direction of storm flows for each lot in the development indicated by flow arrows in front, sides and rear of all lots;
      (17)   Area in square feet of existing and proposed impervious surface;
      (18)   Off-site drainage areas contributing runoff to the site;
      (19)   Base flood elevation, flood fringe, and regulatory floodway;
      (20)   The limits of designated regulatory and non-regulatory wetland areas;
      (21)   The location and limits of known sinkholes (i.e. karst areas);
      (22)   Any known designated natural areas, prime farmland; and
      (23)   Any known proposed environmental mitigation features.
   (D)   Mapping. A copy of the Soil and Water Conservation District maps for the property including all off-site areas that contribute drainage to the site and the applicable soils classification data.
(Ord. 2017-03, passed 3-6-2017)