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Ord 066-97 7/1/1997r� ORDINANCE NO. 66-q AN ORDINANCE REGULATING THE RATE OF DISCHARGE OF STORM WATER RUNOFF: SPECIFYING CRITERIA FOR DETERMINING RUNOFF RATES: ESTABLISHING DEVELOPMENT STANDARDS FOR THE CONSTRUCTION OF RUNOFF CONTROL FACILITIES: AND SETTING FORTH PROCEDURES FOR THE ADMINISTRATION THEREOF BE IT ORDAINED BY THE CITY COUNCIL OF THE CITY OF WICHITA FALLS, TEXAS THAT: SECTION I. PURPOSE. It is the purpose of this ordinance to establish maximum rates for the discharge of storm waters into the various watercourses of the City for the purpose of promoting the health, safety and general welfare of the population by minimizing or eliminating dangers of flooding to life and property. It is further the intent of this ordinance that runoff control devices be provided as areas of land are developed or redeveloped for urban use. It is not the intent of this ordinance to utilize areas for the sole purpose of storing or detaining excess storm water, but to permit such areas to be used for other compatible urban uses as well. SECTION II. DEFINITIONS. A. Storm Water Runoff. Water that results from precipitation which is not absorbed by soil or plant material. B. Natural Drainagge. Water which flows by gravity in channels formed by the surface topography of the earth prior to changes made by the efforts of man. C. Excess Storm Water. That portion of storm water runoff which exceeds the transportation capacity of storm sewers or natural drainage channels serving a specific watershed. D. Excess Storm Water Passage. A channel formed in the ground surface to carry storm water runoff through a specific area. E. Storm Water Release Rate. The rate at which storm water runoff is released from dominant to servient land. F. Storm Water Storage Area. An area designated to temporarily accumulate excess storm water. G. Tributary Watershed. The entire catchment area that contributes storm water runoff to a given point. 1 f!. Dry Bottom Storm Water Storage Area. A facility that is designed to be normally dry and which accumulates excess storm water only during periods when the restricted storm water runoff release rate is less than the storm water inflow rate. I. Wet Bottom Storm Water Storage Area. A facility that contains a body of water and which accumulates excess storm water during periods when the restricted storm water runoff release rate is less than the storm water inflow rate. J. Control Structure. A facility volume of storm water runoff specific length of time. K. Positive Gravity Outlet. A drainage of an area in a manne removal of all surface water by constructed to regulate the that is conveyed during a term used to describe the �r that will ensure complete means of natural gravity. L. Safe Storm Water Drainage Capacity. The quantity of storm water runoff that can be transported within a channel, passage, conduit, tube, duct, or combination thereof in such a manner that the elevation of the water does not rise sufficiently above the level of the adjacent ground surface so as to cause damage to structures or facilities located thereon. M. Low Flow. The transport or flow of a normal or usual volume of storm water as opposed to a high or peak volume which would utilize overflow facilities. N. City. The City of Wichita Falls, Texas. 0. Director of Public Works. The Director of Public Works or his /her designate. P. Gross Aggregate Area. The area of the development under consideration plus the area of any contiguous land, owned or controlled by the developing entity. SECTION III. REGULATIONS. The Department of Public Works of the City of Wichita Falls, Texas, shall develop and establish written policies, procedures, criteria and regulations concerning the inspection, determination and approval of the standards for the construction and /or development of storm water management structures. Such rules and regulations shall be adopted by resolution by the City Council. SECTION IV. ADMINISTRATION. A. Prior to the construction of any storm water control structure or storm water detention facility on the construction or development site, the developer shall obtain a building permit. No such permit shall be issued until the 2 following documents have been submitted to the Director of Public Works and approved: 1. Plans and proposed methods for the prevention and control of soil erosion. 2. Plans, specifications and all calculations for the control of storm water runoff as required by this ordinance and any rules and regulations promulgated by the Director. B. No building permits for habitable structures shall be issued for any development or redevelopment not complying with this ordinance. C. Any decision of the Director shall be pursuant to written specifications and regulations as adopted by the City Council. SECTION V. APPLICATION. This ordinance shall apply to any residential development comprising a gross aggregate area of two (2) acres or more or to any commercial, industrial, institutional, governmental, utility or other development or redevelopment comprising a gross aggregate area of one (1) acre or more. The gross aggregate shall include undedicated streets and other dedicated lands. This ordinance shall not apply to existing streets. SECTION VI. GENERAL REQUIREMENTS. A. Storm Water Release Rate. The controlled release rate of storm water runoff for post development conditions shall not exceed the runoff for predevelopment conditions. The release rate shall be calculated with the water surface in the detention pond at the storm frequency being considered. The volume and release rate calculations shall be based on "Criteria for Storm Water Facilities." Where a proposed development contains only a portion of a watershed or portions of several watersheds, the release rate and storage requirements shall be based upon the proportion of the area being developed as compared to the entire watershed tributary to the proposed storage area. Where it can be demonstrated by the Developer that a higher storm water release rate will not be contrary to the purpose and intent of this ordinance and where such proposed release rate will not adversely affect properties in the downstream portion of the fully developed watershed, the Director may permit such release rate to be used as deemed appropriate. B. Excess Storm Water Passage. 1. An excess storm water passage shall be provided for all storm water storage areas. Such passage shall have capacity to convey through the proposed development the excess storm water from the tributary watershed. The 3 capacity of such excess storm water passage shall be constructed in such a manner as to transport the peak rate of runoff from a 100 year return frequency storm assuming all control structures are inoperative, all upstream areas are fully developed in accordance with the City's current land use plan. 2. No buildings or structures shall be constructed within such passage, however, street, parking lots, playgrounds, park areas, pedestrian walkways, utility easements and other open space shall be considered compatible uses. In the event such passageway is reshaped or its capacity to transport excess storm water otherwise restricted, the Director shall notify the agency, party or parties causing said restriction to remove the same, and set a reasonable time for its removal. If said persons refuse to or are unable to comply with said order, the Director shall cause said restrictions removed at the expense of said persons. 3. Where a proposed development contains existing natural drainage, appropriate land planning shall be undertaken to preserve said natural drainage as part of the excess storm water passage. C. Determination of Storage Capacity. The volume of required storm water storage shall be calculated on the basis of the runoff from a 100 year return frequency storm. Such calculation shall be made in accordance with modified rational hydrograph method of analysis as discussed in "Urban Storm Water Management Special Report No. 49" as published by the American Public Works Association, or other method approved by the Director. The applicable storm water runoff release rate shall be considered when calculating the required storm water storage capacity. D. Compensating Storage. In the event the orderly and reasonable development of an area requires the storage of excess storm water to be located elsewhere, compensating storage (the storage of an equal volume of excess storm water) may be provided at an alternative location provided, however, that the feasibility and details of storm water control shall be approved by the Director. E. Easements. Easements passages, storm water structures shall be gra repair, alteration or however, the City shall easement or any portion which cover excess storm water storage areas and other control nted to the City for the purpose of to insure their proper operation, reserve the right not to accept such thereof. SECTION VII. DRY BOTTOM STORM WATER STORAGE AREAS. A. Design Criteria. 1. Primary and Secondary Uses. Dry bottom storm water storage areas shall be designed to serve a secondary 4 purpose for recreation, open space, parking lot, or similar type of use that will not be adversely affected by occasional intermittent flooding. 2. Drain System. A drainage system shall be provided to transport low flow storm water runoff through storage areas. Such drainage systems shall have a positive gravity outlet to a natural passage or storm drain with adequate capacity as described in Section VI, Subsection B. No outlets from a storm water storage area are to be less than four (4) inches in diameter. 3. Storage Duration. The combination of storage of excess storm water runoff from a 100 year return frequency storm and the allowable release rate shall not result in a storage duration in excess of forty -eight (48) hours. 4. Grades. Where turf areas are used for the bottom of dry bottom storage areas, the minimum grades for such areas shall be one -half (.5) percent (200 units horizontal to 1 unit vertical). Maximum side slopes for turf shall be twenty -five (25) percent (4 units horizontal to 1 unit vertical). Storage area side slopes shall follow the natural land contours in order to minimize the amount of earth work necessary to create the storage facility. 5. Erosion Control. Erosion control measures consisting of mulch, hydro- seeding, nurse crops, sod installation or other approved means shall be utilized to control soil movement within and around the storage basin. Energy dissipating devices or stilling basins shall be provided to ensure that downstream soil erosion is alleviated and the regime of the downstream drainage facility is not disturbed. 6. Control Structures. Control structures shall be designed as simple as possible and shall not require manual adjustments for normal operation. Control structures shall be designed to maintain a relatively uniform flow independent of storm water storage volume. Inlet structures shall be constructed in such a manner to prevent high velocity flow (above 10 feet per second); to provide for the interception of trash and debris and for soil erosion control. Inlets shall be designed to eliminate turbulent flow conditions during any portion of the storm water storage cycle. Overflows for each storm water storage area shall be provided in the event a storm in excess of the design capacity occurs. Such overflows shall be constructed to function without specific attention and shall become part of the excess storm water passage. 5 SECTION VIII. WET BOTTOM STORM WATER STORAGE AREAS. A. Design Criteria. Wet bottom storm water storage areas shall be designed in accordance with the design criteria governing the construction of dry bottom storm water storage areas, except for drains as required by Section VII.A.2. The following additional regulations shall apply: 1. Construction. Minimum normal water depth shall be two (2) feet. If fish are to be used to keep the pond clean, at least 1/4 of the pond area shall have a minimum depth of five (5) feet. Facilities shall be provided to lower the pond elevation by gravity flow for cleaning purposes and land /water interface maintenance. Protection of the land /water interface shall be provided to alleviate soil erosion due to wave action. 2. Control Structures. Control structures for storm water release shall operate at their maximum rate with only minor increases in the water surface level. 3. Stagnation Control. Measures shall be included in the design to prevent pond stagnation. Such measures may include fountain aeration or other approved means to ensure aerobic pond conditions. 4. Determination of Storage Capacity. When calculating the storage capacity of wet bottom storage areas, only the volume available to store excess storm water shall be considered. Permanent water storage does not constitute control of excess storm water runoff. SECTION IX. MISCELLANEOUS STORM WATER STORAGE AREAS. A. Paved Surfaces. Paved surfaces, including automobile parking lots in proposed storm water storage areas shall have minimum grades of one third (.3) percent (300 units horizontal to one (1) unit vertical) and shall be limited to storage depths of one and one -half (1 -1/2) feet maximum. 6 Pavement base design and construction shall be accomplished in such a manner as to prevent damage from flooding. Control structures in paved areas shall be accessible for maintenance and cleaning. The use of vortex control facilities at inlets to ensure that the maximum allowable release rates are being developed shall be required as necessary. Where parking areas are used to store storm water, the areas of greatest depth shall be restricted to the more remote, least used areas of the parking facility. B. Rooftop Surfaces. Rooftop storage of excess storm water shall be designed with permanent -type control inlets and parapet walls to contain excess storm water. Adequate structural roof design shall be provided to ensure that roof deflection does not occur which could cause roof failure. Overflow areas shall be provided to ensure that the weight of stored storm water will never exceed the structural capacity of the roof. C. Underground Storage. Underground storm water storage facilities shall be designed for easy access to accommodate the removal of accumulated sediment. Such facilities shall be provided with positive gravity outlets. SECTION X. CONTROL IN EXCESS OF REQUIREMENTS. Provision of Control water runoff control requirements of this control would accrue City may provide pub the control of storm benefits received. Exceeding Requirements. In the event storm can be provided in excess of the ordinance and the benefit of such additional to the City of Wichita Falls at large, the Lic participation in the increased cost of water runoff in proportion to the additional SECTION XI. REPEALER. All ordinances or parts of ordinances in conflict with the provisions of this ordinance are hereby repealed PASSED AND APPROVED THIS 1ST DAY OF JULY, 1997. ATTEST: ('41 Wj L CITY CLERK 7 M A Y R,' OR DiNANCE NO. 61 -97 ORDINANCE, WAIVING APPENDIX A, SUBDIVI- SION 9(.13)(2)(a) OF THE CODE OF ORDINANCES WITH RESPECT TO PLACING'CURB AND GUTTER ON THE SOUTH SIDE OF MORGAN LANE, ADJACENT TO THE NORTH LINE OF BLOCK 1, EDEN HOUSING ADDI- TION ORDINANCE NO.62 -97 Here ORDINANCE WAIVING APPENDIX A, SUBDIVI- SION 9(13)(2)(a) OF THE CODE OF ORDINANCES WITH RESPECT TO PLACING CURB. AND GUTTER ON THE SOUTH SIDE OF KOVARIK ROAD, ADJACENT TO THE NORTH LINE OF BLOCK 5, KEMP SUBDIVISION OF W.M. MAYER SUR- V EY A -193:: ORDINANCE NO. 63-97 AN ORDINANCE REZON- ING 519 SULLIVAN STREET, LOT 6 -A, BLK 13 -A, BATESON ADDI- TION, WICHITA FALLS; WICHITA COUNTY, TEX- AS, FROM LIMITED.COM- M E R C 1 A L T O RESIDENTIAL MIXED USE ZONING; FINDING AND DETERMINING THAT THE MEETING AT WHICH THIS ORDINANCE WAS PASSED WAS OPEN TO THE PUBLIC AS RE- QUIRED BYLAW ORDINANCE NO.64 -97 AN ORDINANCE AMEND- ING SECTION 6100, NOW C O N F 0 R M I N G DEVELOPMENT REGU= LATIONS OF THE ZON- ING ORDINANCE; FINDING AND DETER- MINING THAT THE MEETING AT,WHICH p „EMS THIS ORDINANCE WAS MMIC PASSED WAS OPEN TO FTEXAS THE PUBLIC`AS RE- eo"5,17. QUIRED BYLAW ORDINANCE N0:65 -97 waaaww ■waw AN ORDINANCE ADOPT - ING VARIOUS STANDARD -- CODES RELATING TO IN- SPECTION ACTIVITIES OF THE CITY AND EN- FORCEMENT OF BUILD -. ING PROVISIONS AS:' PROVIDED IN SUCH CODES BY AMENDING ARTICLE 11, SECTIONS 7 -14, 7 -15, 7 -16, 7 -17 AND 7 -I8 OF THE CODE OF OR- DINANCES OF THE CITY OF WICHITA FALLS AND BY REPEALING EXIST- ING ORDINANCES CON TRARYTOSUCHCODES ORDINANCES NO.66 -97 AN ORDINANCE REGU- LATING THE RATE OF DISCHARGE OF STORM WATER RUNOFF: SPECI- FYING CRITERIA FOR DETERMINING RUNOFF RATES: ESTABLISHING DEVELOPMENT STAN- DARDS FOR THE CON - STRUCTION OF RUNOFF CONTROL FACILITIES: AND SETTING FORTH PROCEDURES FOR THE ADMINISTRATION THEREOF Affidavit of Publication THE STATE OF TEXAS COUNTY OF WICHITA 15th On #608167 July day of 1997 A.D........ * .. , personally appeared before me, the undersigned authority Pat Chamberlain bookkeeper for the Times Publishing Company of Wichita Falls, publishers of the Wichita Falls Times /Record News, a newspaper published at Wichita Falls in Wichita County, Texas, and upon being duly sworn by me, on oath states that the attached advertisement is a true and correct copy of advertising published in one ( 1) 'issues thereof on the following dates: July 13, 1997 Bookkeeper for Times Publishing Company of Wichita Falls Subscribed and sworn to before me this the day and year first above written-