Drainage plans are required for all activities covered under this chapter. All drainage plans must be approved by the City Engineer before permits are issued or formal approvals granted. Said approval by the City Engineer shall mean that the plan appears to meet the requirements of the city and shall not be interpreted to provide any guarantee or warrantee against damage or inconvenience by flooding or the runoff related problem.
(A) Individual one and two unit residential sites.
(1) By virtue of applying for a building permit the applicant acknowledges that he or she is familiar with the characteristics of the site and the lands adjacent and that the stormwater control measures proposed are appropriate for those characteristics and the proposed house.
(2) Drainage plans may be shown on a sketch prepared by the applicant. It should be drawn as accurately as possible and clearly show all the stormwater control measures proposed for the site. Arrows may be used to show the direction of surface flow. Locations of swales, downspouts and sump pump discharges should be shown with their direction of flow. Specific elevations are not required.
(B) Multiple units residential, commercial, and industrial sites.
(1) Drainage plans and drainage calculations shall be prepared by a Registered Professional Engineer, Land Surveyor, Architect or Landscape Architect licensed to practice in the State of Indiana. Drainage plans and drainage calculations for sites over three acres in size, or with unique and/or sensitive drainage issues shall be prepared by a Registered Professional Engineer or Land Surveyor licensed to practice in the State of Indiana. The designer of the drainage plan shall be liable for any shortcomings or inadequacies in the plan that may reveal themselves after construction.
(2) Drainage plans shall show topographic features, utilities, and locations and existing and proposed elevations of the ground, pavements, drainage course, drainage structures, detention basins, finished floors, and other items that might impact drainage. The drainage plan shall be of sufficient detail to serve as construction drawings and may be incorporated with the site plans required under other sections of this chapter or other provisions of the city.
(3) Drainage calculations shall be provided for the analysis of existing drainage courses and/or the design of any proposed drainage course and/or detention basin and discharge control structures. The calculations shall be in a form and shall use methods as required by the City Engineer and as spelled out in the standards.
(4) The drainage plan and calculations shall be thorough enough to allow a complete analysis of the expected impacts on the site and the areas downstream.
(C) Subdivisions, condominium developments, and Planned Unit Developments (PUD).
(1) Reference should be made to the appropriate sections of this chapter or other appropriate provisions of the city.
(2) Drainage plans shall comply with the requirements of division (B) of this section. The drainage plan shall be presented in concept at the pre-preliminary review stage of the city's approvals process. If the concept is approved, the drainage plan shall be presented in sufficient detail at the Primary Plat Stage to be able to make sound judgments concerning the adequacy of the proposed system. The drainage plan shall be presented in final form prior to the Secondary Plat (or equivalent) Stage. The drainage plan and drainage calculations must be approved by the City Engineer prior to, or simultaneous with, the approval of any construction plans.
(Ord. 26-2008, passed 7-14-08)