City of Broken Arrow
Broken Arrow Stormwater Laws and Regulations
Broken Arrow's regulations are compliant with the Oklahoma Storm Water Program and state regulation Oklahoma Administrative Code 252:606-1-3(b)(3). The city has a stormwater management plan.
Excerpt- Broken Arrow Ordinances
Chapter 25 - STORMWATER MANAGEMENT
The City of Broken Arrow makes the following findings of fact:
- Because of its physical terrain and geographical location, the city is particularly subject to damage from stormwaters, which, from time to time, overflow from existing watercourses and drainage facilities;
- Floodplain areas of the city are subject to periodic inundation which may result in the loss of life and property, health and safety hazards, disruption of commerce and governmental services, and extraordinary public expenditures for flood protection and relief, all of which adversely affect the public health, safety and general welfare;
- The flood losses are created by the cumulative effect of obstructions in floodplains and increase of impervious areas which cause an increase in flood heights and velocities, and by the occupancy of floodplain areas by uses vulnerable to floods and hazardous to other lands because they are inadequately elevated, flood-proofed, or otherwise protected from flood damage;
- Previous regulations addressing drainage requirements for new land development must be replaced by a comprehensive approach in order to prevent or minimize damage to property and to reduce the potential for loss of life;
- A comprehensive approach to managing stormwater runoff and floodplain management is required to address existing and future needs;
- The presently existing stormwater drainage facilities of the city require continuous operation, maintenance, renewal and replacement;
- While the city does not own all drainage facilities within its jurisdiction, it does own or control a sufficiently comprehensive system in each of the major drainage basins so as to make a unified approach to flood issues a desirable and administratively achievable goal;
- The stormwater management program should be funded in the manner of a public utility.
ARTICLE III. - GENERAL WATERSHED DEVELOPMENT REQUIREMENTS
(a) All stormwater runoff shall be subject to review and approval by the city with regard to analysis, design and construction of drainage facilities. The appropriate public authority shall have the right to maintain, or cause to be maintained, the drainage system for its intended purposes. If a basin master drainage plan is adopted for the area under consideration, then the provisions of the plan shall be adhered to unless amended.
(b) The stormwater drainage system, both public and private, may consist of (1) roadways, storm sewers, detention facilities, retention facilities, improved channels; (2) unimproved drainage ways left in their natural condition; (3) the areas covered by drainage way easements for the purpose of providing overland flow; and (4) all appurtenances to the above including inlets, manholes, junction boxes, headwalls, dissipaters, culverts, etc. All portions of the drainage system that exist on or in dedicated street rights-of-way or property owned by the city in fee shall be owned and maintained by the city, unless provided otherwise by agreement or covenant. Improved and natural channels on private property shall be maintained by the property owners. In this context, the removal of dead or dying trees or storm debris shall not be considered to alter the channel so as to make it no longer a natural channel.
(c) Every development shall be provided with a stormwater drainage system designed by an engineer registered in the State of Oklahoma, adequate to serve the development, and otherwise shall meet the approval requirements of the officials having jurisdiction.
(d) The stormwater drainage system shall be designed so that property owners located downstream from and upstream from the development shall not be injuriously affected by the construction, operation, or maintenance of such system.
(e) The stormwater drainage system plans prepared and sealed by a professional engineer shall show both plan and profile views of the proposed improvements. Any manhole or access point to the system that is buried out of sight shall be dimensioned to permanent objects in the vicinity.
(f) The stormwater drainage system shall be designed to receive and pass the runoff from a one percent chance storm under ultimate urbanization. In areas covered by the regulatory flood area, that data shall govern. In areas not covered by the regulatory flood area, the design engineer shall prepare and submit a study for the area. The ultimate urbanized flow shall be confined within the said stormwater drainage system.
(g) A minimum of the 20 percent chance and one percent chance storms shall be evaluated when designing the stormwater drainage systems.
Sec. 25-202. - Stormwater collection system.
(a) The stormwater collection system shall be designed either:
- To pass a minimum of the runoff from a 20 percent chance storm in a pipe network together with an overland flow path with capacities so that the combination of the two will pass the runoff from a one per cent chance storm under ultimate urbanized conditions.
- Or, to pass the entire runoff from a one per cent chance storm in the pipe network. Should the entire runoff from a one per cent chance storm be conveyed in an enclosed drainage network, grading shall be designed to convey the runoff from the one per cent chance storm overland in the event of inlet or storm sewer blockage or bypass.
- In either case, an overland drainage easement shall be required for overland flows. No overland flows shall be allowed to adversely affect structures.
- In areas where overland flows may cause problems, the local administrator may require that the entire runoff from the one per cent chance storm shall be conveyed through an enclosed drainage network.
- In areas where ultimate urbanized flows are not planned for conveyance to a regional detention facility, the local administrator may reduce the capacity requirement to the existing condition flows.
(b) The overland flow portion of the collection system shall be confined to dedicated rights-of-way, or drainage easements to assure the stormwater can pass through the development without inundating the lowest level of any building, dwelling, or structure. All drainage easements shall be shown on the plat.
(c) The distance between inlets, as well as the distance to the first inlet on a street shall be determined by the lesser of the following:
- For the one percent chance storm, water depth shall not exceed the top of curb, or
- Six hundred feet.
(d) At sump locations, the water depth shall not exceed six inches above the top of curb, or 12 inches above the top of grate, whichever is less, for the one per cent chance storm. Where sump collection systems are used, an overflow route shall be provided in the event of a complete blockage of the inlet of pipe. If the inlets and pipe are sized for the one per cent chance storm, a sod overflow can be used. If a 20 percent chance storm inlet and pipe system is designed, the overflow area shall be concrete lined. When a sod overflow structure is constructed, it shall be lined with Bermuda grass or approved equal and shall contain energy dissipaters, if required at the outflow point.
(e) Driveway approaches shall be designed and constructed so that the runoff from the one percent chance storm shall not leave the roadway except in locations where the driveway is designed as part of the drainage system.
(f) Runoff from areas greater than one-half acre outside the roadway of arterial and collector streets shall be collected before it reaches the roadway. In no circumstance shall concentrated flows be allowed to discharge into arterial streets. Parking lots shall have internal drainage systems so as to reduce concentrated flow onto streets. This requirement shall not apply to residential lots used as single-family residences. The local administrator may approve sheet flows to the subject streets when connecting to an underground storm sewer system is not economical. In sheet flow instances, the developer must prove no adverse impact to the traveling public, and that the street drainage system is capable of conveying the increased flows.
(g) Site grading shall provide surface water drainage directly into a storm sewer, natural drainage course, improved channel, or paved street without crossing more than four adjacent lots.
(h) No inlets shall be designed for placement within driveways or entries unless individually approved by the local administrator.
(i) Drainage or utility easements of satisfactory width to provide working room for construction and maintenance shall be provided for all stormwater collection systems. In no case shall the total easement width be less than ten feet.
(j) All improved open drainage courses shall be maintained by the owner of the land upon which they are located and by the person or entity actually occupying the land upon which the improved open drainage courses are located. Maintenance called for by this section shall be performed as often as necessary to keep the drainage course free of debris and any wild growth above the height of 18 inches above the finished grade of the improved drainage course. Maintenance as necessary to keep sedimentation from exceeding 12 inches in depth above the finished grade will also be performed. In the event that a person or entity charged with the maintenance of an improved open drainage course allows sedimentation in excess of the limits prescribed above, or allows wild growth or debris in excess of the limits prescribed above, to accumulate within the improved open drainage course, and the premises upon which the sedimentation, wild growth, or debris is allowed to accumulate is hereby expressly declared to be a nuisance. In addition to any other remedies available to the city, such nuisances may be abated in the manner provided under the Broken Arrow Code for any other nuisance.
Sec. 25-205. - General storage requirements.
(a) Detention storage shall be required to accommodate excess runoff from all storms from the 20 percent chance storm up to the one percent chance storm. Excess runoff is that runoff generated due to urbanization which is greater than the runoff historically generated under existing conditions, for a given frequency storm. Detention facilities shall be designed so that the peak rate of discharge does not exceed that of the existing conditions.
(b) Peak release rates from private developments shall not exceed the existing runoff that occurred before development for all storm frequencies up to and including the one percent chance storm. The 20 percent chance, ten per cent chance, two percent chance, and one percent chance storms shall be investigated at a minimum.
(c) Public regional detention facilities may be designed with one percent chance storm outflow rates equal to or lower than pre-development values with possible increased flow rates for the 20 percent chance, ten percent chance, and two percent chance storms from pre-development flow rates under those conditions where downstream areas are not adversely impacted.
(d) If the development is situated in such a manner that the stormwater is discharged into a stormwater system which the local administrator determines will not be adversely affected, the developer may make a monetary payment or some other form of valuable consideration to the city in accordance with section 25-207 of this chapter, in lieu of constructing an onsite detention facility.
(e) Changes may be made to streams or channels within the regulatory flood fringe area; subject to approval of the local administrator, provided that:
- The volume of floodwater storage is not reduced;
- Neither downstream or upstream water surface elevations are adversely increased; and
- All required permits are obtained prior to starting work.
(f) Stormwater detention or other storage facilities shall not be located in street rights-of-way or easements unless it is placed in an enclosed storm sewer system.
Sec. 25-206. - Acceptable types of storage.
Acceptable types of detention or retention facilities:
- Dry detention facilities: Such facilities must be provided with underground drainage or a concrete trickle channel to eliminate standing water after storm periods. This type of facility may be used for recreational purposes and other approved uses to the maximum extent possible when not functioning as a detention facility.
- Wet detention facilities: Such facilities will be used on a limited basis and will be approved only when the pond inflow is sufficient to maintain pond water surface levels and to preclude the water from stagnating.
- Underground detention facilities: This type of facility may consist of basins, tanks, and or oversized storm sewers.
- Parking lot detention: This type of facility may be used provided the maximum one percent chance storm ponding depth is 12 inches or less. Any repaving of the parking lot shall be evaluated for impact on volume and release rates and are subject to approval by the local administrator. All parking lot detention areas shall have a minimum of two signs posted identifying the detention pond area. The signs shall have a minimum of one and one-half (1.5) square feet and contain the following message: "WARNING This area is a stormwater detention facility and is subject to periodic flooding to a depth of (provide one percent chance storm design depth)." Any suitable materials and geometry of the sign is permissible, subject to approval by the local administrator.
- Retention facilities: Such facilities may be used when the existing conditions runoff from a watershed would exceed the capacities of downstream facilities. The retention facility shall contain the one percent chance stormwater runoff and release shall be by evaporation, infiltration or slow release at outflow rates less than existing levels
Sec. 25-415. - Post-construction stormwater impacts.
(a) The purpose of this section is to address the operation, and maintenance requirements of post-construction best management practices and stormwater drainage systems within the City of Broken Arrow to reduce or eliminate post-construction adverse stormwater quality and quantity impacts to the municipal separate storm sewer system, any watercourse of the city, or any waters of the state or United States.
(b) For the purposes of this section, the following shall mean:
Post-construction: The general time period referenced in perpetuity after the final acceptance of the construction phase of any construction activity identified in subsection (c) below.
(c) This section shall be applicable to all post-construction best management practices and stormwater drainage systems on developments which require or required platting, site plan approval, or alterations to existing public stormwater drainage systems. Post-construction operation and maintenance of private best management practices and private drainage systems on single-family residential properties are exempt from the requirements of this section.
(d) Operations and maintenance of post-construction best management practices and stormwater drainage systems shall be performed in such a manner so that adverse stormwater quality and quantity impacts to stormwater drainage systems and receiving streams both on the subject property and on off-site properties are avoided, reduced, or eliminated. Adverse stormwater quality and quantity effects for the purposes of this section include: increased flood elevations, erosion, siltation, sedimentation; reduced base flow; pollution; and degradation of water quality.
(e) Stormwater drainage systems for the purposes of this section include any facility, structure, improvement, development, equipment, property or interest therein, including structural and nonstructural elements, which are made, constructed, used or acquired for the purpose of collecting, containing, storing, conveying, filtering, treating, infiltrating and controlling stormwater. This includes, but is not limited to, detention facilities, retention facilities, sediment basins, ponds, lakes, engineered open channels, natural channels, floodplains, creeks, storm sewers, conduits, pipes, borrow ditches, swales, roadways, infiltration systems, rain gardens, and bio-retention filters.
(f) Post-construction best management practices and stormwater drainage systems shall be operated and maintained so that property owners located downstream from and upstream from the development shall not be injuriously affected.
(g) Operations responsibility of post-construction best management practices and stormwater drainage systems shall be borne by the property owner.
(h) Maintenance responsibility of post-construction best management practices and stormwater drainage systems shall be borne by the property owner.
(i) In the event that the owner fails to properly operate or maintain the post-construction best management practices and stormwater drainage systems such that negative stormwater quality or quantity impacts to the municipal separate storm sewer system, any watercourse of the city, or any waters of the state or United States or stormwater drainage systems and or receiving streams either on the subject property or on off-site properties occurs or is imminent, the City of Broken Arrow, Oklahoma, may order compliance with this section by written notice of violation (NOV) to the owner. Such notice may require without limitation:
- The performance of monitoring, analysis, and reporting;
- The elimination of illicit discharges or connections;
- That violating discharges, practices, or operations shall cease and desist;
- The abatement or remediation of stormwater pollutants and restoration of any affected property;
- The implementation of source control or treatment best management practices; and
- Payment of penalties as set forth as a class A offense per Broken Arrow Code.
If abatement of a violation or the restoration of affected property is required, the notice of violation shall set forth a deadline that such remediation or restoration must be completed. Said notice of violation shall further advise that should the violator fail to complete the remediation or restoration within the established deadline, the work may be performed by the City of Broken Arrow, or its designated contractor, and the cost shall be paid by the owner.
Broken Arrow Stormwater Page
Broken Arrow Ordinances