Corning Municipal Code Art. I General

The purpose of this chapter is to diminish threats to public health and safety caused by the runoff of excessive stormwaters, reduce economic losses to individuals and the community at large, enhance broader social and economic objectives, and protect, conserve and promote the orderly development of land and water resources. The provisions of this chapter further regulate, guide and control:

A. The subdivision, layout and improvement of lands within the city;

B. The excavating, filling and grading of lots and other parcels or areas;

C. The construction of buildings and the drainage of the sites on which those structures are located, to include parking and other paved areas;

D. The design, construction and maintenance of stormwater drainage facilities and systems.

(Ord. 508 §1.01, 1991).

Before starting any of the work regulated by this chapter, an applicant shall comply with the requirements set forth in other applicable ordinances with respect to the submission and approval of preliminary and final subdivision plats, improvement plans, building and zoning permits, inspections, appeals and similar matters, along with those set forth in this chapter, and as may be required by state statutes and the regulations of any department of the state.

(Ord. 508§1.03, 1991).

For the purposes of this chapter, the following definitions are adopted:

1. "Base flood elevation" means the elevation at all locations delineating the maximum level of high waters should the adopted design flood occur.

2. "Capacity of a storm drainage facility" means the maximum ability of a storm drainage facility to convey stormwater flows without causing substantial damage to pub-lic or private property, and in the case of a pipe, without surcharging.

3. "Channel" means a natural or artificial open watercourse with definite bed and banks which periodically or continuously contains moving water or which forms a connecting link between two bodies of water.

4. "Compensatory storage" means an artificially excavated volume of storage within a floodplain used to balance the loss of natural flood storage capacity when artificial fill or structures are placed within the floodplain.

5. "Conduit" means any channel, pipe, sewer or culvert used for the conveyance or movement of water, whether open or closed.

6. "Detention basin" means a facility constructed or modified to restrict the flow of stormwater to a prescribed maximum rate, and to concurrently detain the excess waters that accumulate behind the outlet.

7. "Detention storage" means the temporary detaining or storage of stormwater in storage basins, on rooftops, in streets, parking lots, schoolyards, parks, open space, or other areas under predetermined and controlled conditions, with the rate of drainage therefrom regulated by approp-riately installed devices.

8. "Discharge" means the rate of outflow of water from detention storage.

9. "Drainage area" means the area from which water is carried off by a drainage system, a watershed or catchment area.

10. "Dry bottom detention basin" means a basin designed to be completely dewatered after having provided its planned detention of runoff during a storm event.

11. "Excess stormwater runoff" means the volume and rate of flow of stormwater discharged from an urbanized drainage area which is or will be in excess of that volume and rate which pertained before urbanization.

12. "Flood fringe" means the higher portion of the floodplain, immediately adjacent to and on either side of the floodway, occupied by quiescent or slow-moving waters during floods.

13. "Floodplain" means the special flood hazard lands adjoining a watercourse, the surface elevation of which are lower than the base flood elevation, which are subject to periodic inundation during floods.

14. "Floodway" means the channel of a watercourse and those portions of the adjoining floodplain which are reasonably required to carry and discharge the design flood.

15. "High water elevation" means the elevation of floodwaters of a flood of specified frequency or occurrence at any given point.

16. "Hydrograph" means a graph showing, for a given point on a stream or conduit, the runoff flowrate with respect to time.

17. "Lag" means the elapsed time between the center of mass of a rain event and center of mass of the resultant hydrograph at a specific site.

18. "Leach trench" means a trench designed to hold stormwater and percolate the water into the ground, usually consisting of a horizontal perforated pipe and backfilled with leach rock.

19. "One-hundred-year storm runoff" means the stormwater runoff from a rain event of specific intensity and duration having a one percent probability of occurring in any one year.

20. "One-hundred-year storms" means rainstorms of varying durations and intensities, having a one percent probability of recurring in any one year.

21. "Off-site detention basin" means a feature or structure for temporarily storing excess stormwater originating at two or more urbanized locations, having devices for controlling the rate of release of the stored waters, and located downstream of all controlled areas.

22. "On-site detention basin" means a feature or structure for temporarily storing excess stormwaters, hav-ing devices for controlling the rate of release of the stored waters, and located within the urbanized site where the runoff originates. (See "Off-site detention basin").

23. "Peak flow" means the maximum rate of flow of water at a given point in a channel or conduit resulting from a predetermined storm or flood.

24. "Retention basin" means a structure or feature designed to retain stormwater over a period of time, with its release being positively controlled over a longer period of time than in a detention basin.

25. "Storm sewer" means a closed conduit for conveying collected stormwater.

26. "Stormwater drainage system" means all means, nature or manmade, used for conducting stormwater to, through or from a drainage area to the point of final out-let including, but not limited to, any of the following: conduits and appurtenant features, canals, channels, ditch-es, streams, culverts, streets and pumping stations.

27. "Stormwater drainage facility" means any element in a stormwater drainage system which is made or improved by man.

28. "Stormwater runoff" means the waters derived from melting snow or rain falling within a tributary drainage basin, flowing over the surface of the ground or collected in channels or conduits.

29. "Time of concentration" means the elapsed time for stormwater to flow from the most distant point in a drainage basin to the outlet or point in question.

30. "Urbanization" means the development, change or improvement of any parcel of land consisting of one or more lots for residential, commercial, industrial, institutional, recreational or public utility purposes.

31. "Watercourse" means any stream, natural or artificial depression, slough, gulch, reservoir, lake, pond or natural or manmade drainageway in or into which stormwater runoff and floodwaters flow either regularly or intermit-tently.

32. "Wet bottom detention basin" means a basin designed to retain a permanent pool of water after having provided its planned detention of runoff during a storm event.

(Ord. 508 §1.04, 1991)