City / County of Mobile

Mobile stormwater laws & regulations

Runoff from stormwater is widely regarded as one of the top threats to water quality throughout the country. The Mobile Bay Watershed, which encompasses the state’s largest urban centers, is experiencing the brunt of this threat in Alabama. Growth and development from areas all over the state are challenging waterway health, water supply and aquatic habitat. Urban stormwater impacts are the leading cause of loss of freshwater biodiversity in many southeastern rivers. Sediment and nutrient pollution, erosion and bank collapses from excessive flows, and dewatering of rivers in dry weather damage aquatic habitats and sensitive species. Other impacts of stormwater runoff locally include flooding, loss of wildlife, degradation of waterways valued for recreation, and reduction of limited drinking water supplies. 

The City of Mobile has created an ordinance that establishes requirements for the management of stormwater runoff associated with development activities and also for the long-term operation, maintenance, and repair of stormwater controls and treatment practices onsite once construction is complete. For property owners subject to these regulations, it is their responsibility to ensure compliance with the requirements set forth in the ordinance. Additionally, the City is currently drafting amendments to Chapter 17 of the City Code that will add new provisions addressing post-construction storm water management in new development and re-development, strengthen legal authority for illicit discharge detection and elimination, and require industrial facilities with NPDES permits to submit Discharge Monitoring Reports to the City.

The new program, which replaces an ordinance adopted two years ago, splits land disturbance permits into two tiers: Tier 2 for developments under 1 acre, which will experience no changes than before, and Tier 1 for developments over an acre, which requires developers to submit plans and credit letters to the city. Also, commercial, industrial and "high-risk" facilities will have to submit the same management plan to the city as part of an illicit discharge and detection program within the ordinance.

Stormwater Management Program Plan – City of Mobile May 2014

1.1 Regulatory Overview

This Stormwater Management Program (SWMP) Plan includes pollution prevention measures, stormwater monitoring, use of legal authority, and other appropriate means to control the quality of stormwater discharged from the City of Mobile (City) Separate Storm Sewer System (MS4), in accordance with the Preliminary Draft National Pollutant Discharge Elimination System (NPDES) Permit number ALS000007 and current NPDES Permit number ALS000002. The SWMP is implemented in accordance with Section 402(p)(3)(B) of the Clean Water Act, and the Stormwater Regulations at 40 CFR Part 122.26.

It is the goal of the SWMP to reduce the discharge of pollutants to and from the MS4 to the maximum extent practical (MEP), thus protecting the quality of water in the receiving water bodies. This Stormwater Management Program covers the term of the permit and is updated as necessary, or as required by the Alabama Department of Environmental Management (ADEM), to ensure compliance with the statutory requirements of the Clean Water Act.

Per the NPDES Permit number ALS000007 requirements, BMPs and measureable goals are provided in Sections 3-13 for each program element listed below:

-Storm Water Collection System Operations -Post-Construction Storm Water Management in New Development and Re-Development -Oils, Toxics, and Household Hazardous Waste Control
-Public Education and Public Involvement on Storm Water Impacts -Spill Prevention and Response -Industrial Storm Water Runoff
-Illicit Discharge Detection and Elimination -Pollution Prevention/Good Housekeeping for Municipal Operations -Wet-Weather Monitoring and Reporting
-Construction Site Storm Water Runoff Control -Application of Pesticide, Herbicide, and Fertilizers

 

1.2 MS4 Jurisdictional Boundary

The City’s MS4 boundary is bounded by Mobile Bay to the east, City of Prichard’s MS4 to the north, and Mobile County’s MS4 to the west and south. The City’s MS4 boundary includes parts of nine sub-watersheds: Bayou Sara, Chickasaw Creek, Dog River, Millers Creek, Mobile Bay, Mobile River, Muddy Creek, Pierce Creek, and Threemile Creek. The City’s MS4 covers approximately 148 square miles of industrial, commercial, and residential properties, undeveloped land, wetlands, and tidally influenced streams. Maps showing the jurisdictional boundary with sub-watersheds and land use are provided in Appendix A.

Mobile Municipal Code

CHAPTER 17 - ARTICLE I. - STORMWATER MANAGEMENT AND FLOOD CONTROL

DIVISION 1. - GENERAL

Subpart A. - General Provisions

Sec. 17-1. - Purpose; applicability; manual; jurisdiction; compliance; abrogration; interpretation; severability.

(a)          Statement of purpose. It is the purpose of this article to control land disturbance activities and stormwater drainage facilities within the corporate limits of the city in order to promote the public health, safety and general welfare, and to comply with the Federal Clean Water Act, the Alabama Water Pollution Control Act, as amended, Alabama Code (1975), § 22-21-1, et seq., the Alabama Environmental Management Act, as amended, Alabama Code (1975), § 22-22A-1, et seq., and rules and regulations adopted thereunder, the national pollution discharge elimination system (NPDES) program to meet its stormwater discharge permit requirements, and Federal Emergency Management Agency (FEMA) requirements to reduce flooding through provisions designed to:

  1. Protect human life and health;
  2. Protect the natural assets and resources of the city;
  3. Protect the lands and waters of the city from the effects of soil erosion, sedimentation, and illicit discharges into its municipal separate storm sewer system;
  4. Prevent and reduce degradation of streams and lakes from the effects of siltation and illicit discharges;
  5. Prevent obstruction of drainage channels, reduce flood damage and prevent damage to the property of adjacent land owners;
  6. Enforce the city's stormwater management program;
  7. Reduce the need for rescue and relief efforts associated with flooding;
  8. Provide for the sound use and development of flood-prone areas so as to maximize beneficial use without increasing flood hazard potential;
  9. Reduce damage to public facilities and utilities such as water and sewer lines, electric, telephone and gas facilities, and streets and bridges located in floodplains;
  10. Ensure a functional stormwater drainage system that will not result in excessive maintenance costs;
  11. Encourage the improvement of existing flooding problems in conjunction with new development that enhances and does not impair the city's stormwater drainage system;
  12. Encourage the use of natural and aesthetically pleasing design;
  13. Reduce the impact on public and private lands caused by the accumulation of mud, dirt, water, debris and construction materials.

(b)          Applicability. This article shall apply to all areas within the city limits.

(c)           Stormwater design manual. The city may furnish additional policy, criteria and information including specifications and standards, for the proper implementation of the requirements of this division and may provide such information in the city floodplain management plan, which is available for review and copying at the office of the city clerk and on the city website, or in the form of a stormwater design manual.

This manual will include a list of acceptable stormwater treatment practices, including the specific design criteria and operation and maintenance requirements for each stormwater practice. The manual may be updated and expanded from time to time, at the discretion of the city engineer, based on improvements in engineering, science, monitoring and experience. Stormwater treatment practices that are designed and constructed in accordance with these design and sizing criteria will be presumed to meet the minimum water quality performance standards.

(d)          Jurisdiction. The regulations and requirements set forth in this article shall apply to all property within the corporate limits of the city.

(e)          Compliance. No structure or land shall hereafter be located, extended, converted or structurally altered without full compliance with the terms of this article and other applicable regulations.

Sec. 17-3. - Designation of administrator.

The city engineer is hereby appointed to administer and implement the provisions of this article in coordination with the urban development department who will administer and enforce any portion of this article as it applies to building permitting and land use.

(Ord. No. 17-025-2014, 7-8-14 )

Sec. 17-4. - Authority of the city engineer.

(a)          The city engineer may furnish additional policy, criteria and information for proper implementation of this division through the city floodplain management plan (copy available on city website) or a stormwater design manual (see subsection 17-1(c)), which may be amended from time to time as needed.

Sec. 17-7. - Plans for commercial, residential and subdivision construction.

(a)    A full set of construction plans, standards, design criteria and other specifications for commercial, residential and subdivision construction, including site grading and drainage plans, hereinafter in this section sometimes referred to as "the plan" or "plans" must be submitted to the city by all applicants for land disturbance and development permits.

(b)   Plans shall be accompanied by sufficient engineering calculations for verification of discharge of stormwater runoff and location and methods for erosion and sedimentation control.

(c)    Plans and supporting documentation shall be certified by a registered professional engineer licensed by the state that;

  1.     The plans provide for proper drainage of the project according to sound engineering principles; and
  2.     The post-development runoff rate does not exceed the pre-development runoff rate as established by the city engineer.

(d)   All data, engineering computations and plans submitted to the city shall be signed and sealed by a professional engineer licensed by the state.

(e)    No construction, whether by private or public action, shall be performed in such a manner as to increase the degree or potential for flooding in its vicinity or in other areas whether by increasing runoff volume or velocity or by diminishing channel or overbank storage capacity.

(f)    The plan shall include provisions for a design that will not cause the pre-development peak runoff rate from a ten-year storm to increase.

(g)   The plan shall provide stormwater detention/retention storage and/or channel improvement and/or other adequate measures as required by applicable design criteria adopted by the city and other specifications for the preparation of site grading and drainage plans.

(h)    For tier 1 land disturbance, a construction best management plan meeting the requirements of section 17-9 of this division will be required. For tier 2 land disturbance, an erosion control plan will be required. CBMPs shall be followed for all projects.

(i)     Plans for development sites of four thousand (4,000) square feet or more shall not allow stormwater which has been diverted from its pre-development natural flow to cross adjoining property lines unless:

(1)   

a.    Stormwaters drain into the city drainage system or a natural stream; and

b.    Stormwaters do not cause the pre-development peak runoff rate to increase; and

c.     The plan limits discharge to the pre-development flow from a ten-year frequency storm; or

(2)   

a.    A release is obtained from the owner of the adjoining property that releases the city from any claims arising from upstream development, runs with the land, and is recorded in the records of the probate court of the county; and

b.    Stormwaters do not cause the pre-development peak runoff rate to increase; and

c.     The plan limits discharge to the pre-development flow from a ten-year frequency storm; or

(3)   

a.    The plan design provides for retention for a one hundred-year frequency storm; and

b.    The plan limits discharge to the pre-development flow from a two-year frequency storm; and

c.     The engineer of record quantifies the pre-development velocity (feet/second) for a two-year frequency storm and certifies that the post-development velocity of stormwater released onto the adjacent property is equal to or less than the pre-development velocity.

(j)     For tier 1 and applicable tier 2 land disturbance projects, the operation and maintenance of the stormwater detention/retention facility shall be the responsibility of the owner/developer, its successors and assignees. The engineer of record shall be responsible for instructing the owner/developer, successors and assignees, in the proper operation and maintenance of the facility, see section 17-10 on maintenance and repair of stormwater facilities.

(k)    The city assumes no liability for the design, performance and operation of any stormwater detention/retention facilities, but, instead, in its review of plans relies on the professional judgment of the engineer or other licensed professional of record.

(l)     Development sites that are less than four thousand (4,000) square feet are exempt from the requirements of subsection (i) above; provided, however, that a development site may not be divided into parts of less than four thousand (4,000) square feet for the purpose of avoiding the requirements of subsection (9).

(m)   No plan shall contain a design that allows stormwater to flow across public rights-of-way unless authorized by the city engineer.

(n)    All construction plans will be required to comply with FEMA floodplain regulations as specified in division 2 of this article.

(o)   As-built certification. A State of Alabama licensed professional engineer must certify to the city engineer that all site construction, street construction, drainage facilities, erosion and sedimentation control measures, and their improvements are complete and functioning as required by the appropriate regulations and approved permits and plans.

(Ord. No. 17-025-2014, 7-8-14 )

Sec. 17-9. - Best management practices—Tier 1 land disturbance permit.

(d)   Waivers of stormwater management requirements.

(1)    Every applicant for a tier 1 land disturbance permit shall provide for stormwater management both during construction and post-construction as required by this division, unless a written request is filed to waive this requirement. Requests to waive the stormwater management plan requirements shall be submitted to the city engineer for approval.

(2)    The minimum requirements for stormwater management may be waived in whole or in part upon written request of the applicant, provided that at least one (1) of the following conditions applies:

a.     It can be determined that the proposed development is not likely to impair attainment of the objectives of this division.

b.    Alternative minimum requirements for on-site management of stormwater discharges have been established in a stormwater management plan approved by the city engineer and implemented pursuant to this division.

c.     Provisions are made to manage stormwater through an off-site facility. The off-site facility is required to be in place, to be designated and adequately sized to provide a level of stormwater control that is equal to or greater than that which would be afforded by on-site practices and there is a legally obligated entity responsible for long-term operation and maintenance of the stormwater practice.

d.    The city engineer finds that meeting the minimum on-site management requirements is not feasible due to the natural or existing physical characteristics of the site.

e.     Non-structural practices will be used on the site that reduce:

1.     The generation of stormwater from the site; and

2.     The size and cost of stormwater storage; and the pollutants generated at the site.

f.     The city will not grant a waiver if to do so would cause any of the following impacts to downstream waterways:

1.     Deterioration of existing culverts, bridges, dams, or other structures, or any element of the city's MS4, private water courses, waters of the state or of the United States;

2.     Degradation of biological functions or habitat;

3.     Accelerated streambank or streambed erosion or siltation;

4.     Increased threat of flood damage to public health, life, property.

g.    In order to be eligible for a waiver, the applicant must complete a mitigation measure, which may include but is not limited to one (1) of the following:

1.     The purchase and donation of privately owned lands, or the grant of an easement to be dedicated for preservation and/or reforestation. These lands should be located adjacent to the stream corridor in order to provide permanent buffer areas to protect water quality and aquatic habitat. The donation shall run with the land, and shall be recorded in the records of the Office of the Probate Court, Mobile County.

2.     The creation of a stormwater management facility or other drainage improvements on previously developed properties, public or private, that currently lack stormwater management facilities designed and constructed in accordance with the purposes and standards of this division.

3.     Payment of a fee in lieu of stormwater practices may be accepted when implementation of otherwise applicable stormwater practices is impracticable under the provisions of this subsection. The fee will be determined according to a fee schedule established by the city based on the size and type of the development activity.

(Ord. No. 17-025-2014, 7-8-14 )

Sec. 17-10. - Maintenance and repair of stormwater facilities—Post-construction stormwater management in new development and redevelopment.

(a)    Maintenance easement—Tier 1 developments. Prior to the issuance of a tier 1 permit, the owner of the site must agree to a maintenance easement that runs with the land and provides the city all authority required to monitor and enforce BMPs. If the land is to be subdivided, the maintenance easement shall be identified on the subdivision plat recorded in the records of the probate judge for the county. The easement shall provide for access to the property at reasonable times for periodic inspection by the city, and for regular or special assessments of property owners to ensure that the facility is maintained in proper working condition to meet design standards and any other provisions established by this division. Any stormwater easement agreement that does not appear on a subdivision plat shall be recorded in the records of the probate judge for the county.

(b)   Maintenance covenants—Tier 1 developments. Maintenance of all stormwater management BMPs shall be ensured through the creation of a formal maintenance covenant that must be approved by the city and recorded in the records of the probate judge for the county, prior to final plan approval. The covenant shall include a schedule for routine maintenance checks, and periodic inspections in a frequency sufficient to assure the proper performance of the BMPs. Maintenance and inspection shall be the responsibility of the property owner.

In the event the stormwater BMPs fail to perform effectively, the parties may amend the maintenance covenants by written amendment recorded in the records of the probate judge for the county.

(c)    Records of installation and maintenance activities. Parties responsible for the operation and maintenance of a stormwater management BMPs shall make records of the installation and of all maintenance and repairs, and shall retain the records for at least five (5) years. Inspections shall be completed by a QCI or QCP. These records shall be submitted to the city engineer annually on January 1 or such other date designated by the city engineer. In the event the responsible party fails to provide the annual records, city officials may conduct an inspection of the property. The fee for said inspection shall be five hundred dollars ($500.00) or the actual cost of inspection, whichever is greater.

(d)   Failure to maintain practices. If a responsible party fails or refuses to meet the requirements of the maintenance covenant, the city, after reasonable notice, may correct a violation of the design standards or maintenance needs by performing all necessary work to restore or repair the BMPs. In the event that the stormwater run-off becomes a danger to public safety or public health, the city shall notify the party responsible for maintenance of the BMPs in writing. Upon receipt of that notice, the responsible person shall have fifteen (15) days to correct the deficiency in an approved manner depending upon the severity and nature of the violation. After proper notice, the city may assess the owner(s) of the facility for the cost of repair work and any penalties; and the cost of the work shall be a lien on the property, or prorated against the beneficial users of the property, and may be collected as a municipal lien in accordance with the procedures applicable to the abatement of public nuisances.

(e)    Unauthorized discharge prohibited and declared a public nuisance.

(1)          Unauthorized discharges prohibited. Any discharge of stormwater made in violation of this division or of any condition of a tier 1 land disturbance permit issued or maintenance covenant, see section 17-10(b), entered pursuant to this division is prohibited and is hereby declared a public nuisance subject to correction and/or abatement in accordance with applicable law.

(f)    Accidental discharges.

(1)    Release of hazardous materials. In the event of any discharge of a hazardous substance or a significant spill of a hazardous substance to the MS4 which could constitute a threat to human health or the environment, the premises owner or operator of the premises shall immediately notify emergency response agencies of the occurrence via emergency dispatch services (911) and shall also notify the city 311 operator by phone or e-mail as soon as possible but not later than twenty-four (24) hours from the date and time of the release as to the occurrence of and the quantity of the release.

(2)    Release of non-hazardous materials. In the event of a release of non-hazardous materials to the MS4, said person shall notify the fire department and the city 311 operator by phone or e-mail as soon as possible but no later than twenty-four (24) hours from the date and time of the release as to the occurrence of and the quantity of the release.

(3)    The owner or operator of property on which a release identified in paragraph (1) or (2) above occurs, shall take all necessary steps to ensure the discovery, containment and cleanup of such spill so as to minimize any adverse impact to the waters of the state and waters of the United States caused by discharges to the MS4, including such improved or additional monitoring as may be necessary to determine the nature and impact of the discharge. Absent a compelling public interest to the contrary, it shall not be a defense for the owner or operator in an enforcement action that it would have necessary to halt or reduce the business or activity of the site, or any project or facility thereon, to maintain water quality and minimize any adverse impact that the discharge may cause.

Notifications in person or by phone shall be confirmed by written notice addressed and mailed to the city engineer within three (3) business days of date of the phone or in person notice.

(4)    Failure to provide notification of a release as provided above is a violation of this division.

(g)   Immediate threats to public health, welfare or the environment. Notwithstanding any other provision in this division to the contrary, in the event of an immediate threat to the public health or welfare, the city may take all appropriate measures to remove or alleviate such threat.

(Ord. No. 17-025-2014, 7-8-14 )

Sec. 17-11. - Illicit discharge detection and elimination ("IDDE").

(a)    Applicability. This section 17-11 applies to all properties (whether developed or undeveloped) that have stormwater discharges associated with them and all land uses within the city, including, but not limited to, residential, industrial, commercial, agricultural, and construction activity.

(b)   Regulatory consistency. This division shall be construed to assure consistency with the requirements of the CWA and the AWPCA and acts amendatory thereof or supplementary thereto or any other applicable regulations.

(c)    Ultimate responsibility. The standards set forth herein and promulgated pursuant to this division are minimum standards; therefore this division does not intend to imply that compliance by any person will ensure that there will be no contamination, pollution, nor unauthorized discharge of pollutants.

(d)   Prohibitions of illicit discharges and illicit connections.

(1)    Prohibition of illicit discharges.

a.            Prohibition. Unless otherwise excepted herein, no person shall spill, dump, throw, drain, make, cause to be made or continue to be made; allow others under such person's control to spill, dump, throw, drain, make, cause to be made or continue to be made; or otherwise discharge and/or dispose of into the city's MS4 or watercourses any illicit discharge, including but not limited to pollutants or waters containing any pollutants, other than stormwater.

Sec. 17-12. - Commercial, industrial and high-risk facilities.

(a)    BMPs required. All commercial, industrial and high-risk facilities (see the definition of "high-risk facility" herein), shall identify, implement and maintain BMPs for any activity, operation or facility which may cause or contribute to pollution or contamination of stormwater, the MS4, private watercourse waters of the state or waters of the United States. Noncompliance with such BMPs will constitute a violation of this division.

(b)   Protection against accidental discharge. The owner or operator of a commercial, industrial or high-risk facility shall provide, at its own expense, reasonable protection from accidental discharge of prohibited materials or other wastes into the MS4 or private watercourses, waters of the state, or waters of the United States, through the use of structural and non-structural BMPs. Any person responsible for a commercial, industrial or high-risk facility which is, or may be, the source of an illicit discharge, may be required to implement, at said person's expense, additional structural and non-structural BMPs to prevent the discharge of pollutants to the MS4.

Sec. 17-14. - Violations, enforcement and penalties.

(a)    Violations. It shall be unlawful and a misdemeanor for any person to:

(1)    Violate any provision of this division;

(2)    Violate the provision of any permit issued pursuant to this division;

(3)    Fail or refuse to comply with any lawful order or notice to abate issued by the city; or

(4)    Violate the provisions of conditions and safeguards established in connection with grants of variance or special exceptions.

(b)   Enforcement remedies for violations.

(1)          Notices, citations. When the city has reason to believe that any person or legal entity has violated or continues to violate any provision of this division or any order issued hereunder, the city may serve that person a verbal warning, and, subsequent to that, a written notice of violation ("NOV") citing the particular violation(s) and requesting the offender immediately seek to remedy it. Investigation and/or resolution of the matter in response to the NOV do not relieve the alleged violator of liability for any violations occurring before or after receipt of the NOV. If the violation is not remedied within a reasonable time after issuance of the NOV, the city or its agent may cause to be served on the violator a municipal offense ticket ("MOT"), a uniform non-traffic citation and complaint ("UNTCC"), or swear out a complaint and summons before a magistrate for appearance of the violator in municipal court.

ARTICLE II. - STORMWATER MANAGEMENT UTILITY DIVISION

Sec. 17-32. - Stormwater management utility division created.

The city council hereby ordains the establishment of the stormwater management utility division of the department of public works. The stormwater management division shall be responsible for developing and implementing stormwater management plans and managing facilities, stormwater systems and stormwater sewers. This division shall charge a storm drainage service charge based on individual contribution of runoff to the system, benefits enjoyed and service received. The stormwater management utility division shall be administered by the city stormwater management engineer under the direction and supervision of the director of public services.

(Ord. No. 65-007-2009, 3-10-09)

Sec. 17-33. - Organization of utility division.

(a)    The stormwater management utility division of the department of public works of the city shall have the responsibility for planning, developing and implementing stormwater management plans; financing, constructing, maintaining, rehabilitating, inspecting and managing existing and new stormwater facilities, collecting fees and charges for the utility division; implementing and enforcing the provisions of the stormwater management code; and other related duties as directed by the mayor.

(b)   The utility division shall be administered by the utility engineer who shall be the superintendent of the division's facilities.

(Ord. No. 65-007-2009, 3-10-09)

Sec. 17-34. - Stormwater fund.

All revenues generated by or on behalf of the utility division and interest earnings on those revenues shall be deposited in a stormwater fund and used exclusively for utility division purposes.

(Ord. No. 65-007-2009, 3-10-09)

ARTICLE III. - STORMWATER MANAGEMENT

DIVISION 1. - GENERALLY

Sec. 17-35. - Scope.

(a)    The purpose of the stormwater management provisions is to provide for effective management and financing of a stormwater system within the city, to provide a mechanism for mitigating the damaging effects of uncontrolled and unplanned stormwater runoff, to improve the public health, safety and welfare by providing for the safe and efficient capture and conveyance of stormwater runoff and the correction of stormwater problems, to authorize the establishment and implementation of a master plan for storm drainage including operation, maintenance, inspection and enforcement, to establish reasonable storm drainage service charges based on each property's contribution of stormwater runoff to the system and use and benefit of services and facilities and to encourage and facilitate urban water resources management techniques including detention of stormwater runoff, minimization of the need to construct storm sewers, and the enhancement of the environment.

(b)   In order to accomplish such purpose a storm drainage service charge shall be made on each lot or parcel in the city. Each property's contribution to runoff shall be the primary consideration in establishing the service charge. Secondary consideration shall be given to specific service requirements of some properties, and special and general benefits accruing to or from properties as a result of providing their own stormwater management facilities.

(c)    The storm drainage service charges shall bear a reasonable relationship to the cost of providing service and facilities. Similar properties shall pay similar stormwater service charges and such charges shall reflect the area of each property and its intensity of development, as these factors bear directly on the peak rate of stormwater runoff.

(d)   An appeal shall be employed to review stormwater charges when circumstances exist which alter runoff characteristics or when either service or benefit varies from a normal condition or is of greater significance than contribution to runoff.

(Ord. No. 65-007-2009, 3-10-09)

DIVISION 2. - CHARGES

Sec. 17-41. - Storm drainage service charge.

(a)    A storm drainage service charge shall be imposed on each lot and parcel of land within the city, and the owner thereof, excepting only streets, boulevards, alleys, viaducts, sidewalks, curbing, street crossings, grade separations, other public ways and easements and highway structures and appurtenances belonging to the city.

(b)   Underdeveloped land shall be exempted from stormwater service charges.

(c)    Road and freeway rights-of-way shall be exempted from the storm drainage service charge as they function as part of the stormwater collection and conveyance system. Railroads and other rights-of-way are not exempt from the stormwater drainage service charge.

(d)   Properties that have existing stormwater detention facilities, or those utilizing such facilities, may have their storm drainage service charges reduced as determined by the utility engineer, in accordance with generally accepted engineering standards and practices to more accurately reflect the contribution to runoff from the property and the level of service provided to such property. The detention facilities must be in accord with the hydrologic, hydraulic and structural design requirements of the rules and regulations. Facilities of a temporary nature will not be allowed a decrease in their charges.

(Ord. No. 65-007-2009, 3-10-09)

Sec. 17-42. - Monthly charge per equivalent runoff unit (eru).

The monthly charge per equivalent runoff unit shall be three dollars ($3.00) maximum.

(Ord. No. 65-007-2009, 3-10-09)

Sec. 17-43. - Rates.

(a)    The utility engineer, shall establish a flat storm drainage charge for each of several categories of residential dwellings. The storm drainage charge for residential categories shall be based on typical ERUs for each category. The smallest residential category shall have an ERU on one (1) and the largest shall have an ERU of two (2).

(b)   The storm drainage charge for each nonresidential property or residential property not covered by paragraph (a) above shall be based on the actual ERUs calculated for such lot or parcel multiplied by the monthly storm drainage charge.

(Ord. No. 65-007-2009, 3-10-09)

Stormwater Management Program Plan – City of Mobile

7.0 POST-CONSTRUCTION RUNOFF CONTROL

7.1 Requirements and Standards

Following construction completion, the City currently requires as-built drawings if there were significant changes from the approved plans submitted for the Land Disturbance Permit. These as-built drawings must show where the detention connects to the MS4. Additionally, a video of the underground detention system as well as the tie from the underground detention system to the City right of way and underground pipe in the rightof-ways is required, where applicable. The City will implement a requirement for developers to submit an “As-Built Certification” along with the as-built drawings within 120 days of project completion before a temporary certificate of occupancy will be issued for all qualifying construction sites. The As-Built Certification shall include flow calculations, if there are any revisions from the permit submittal. The City conducts As-Built and right-of-way inspections.

The City is currently developing post-construction runoff control standards to be required and enforced at all qualifying sites. These standards will be utilized for all approved land disturbance permits dated after the effective date of the revised stormwater ordinance. Post-construction BMPs must be designed and constructed to provide runoff that mimics the pre-development hydrology for, a minimum, 1.14 inch rainfall over a 24-hour period preceded by a 72-hour antecedent dry period. Pre-development and post-development drainage calculations must be prepared and sealed by an Alabama Licensed Professional Engineer and submitted with the Land Disturbance Permit Application and with the As-Built Certification.

7.2 Post-Construction Inspections

The City is currently developing a program for performing post-construction inspections on all qualifying sites with approved land disturbance permits dated after the effective date of the revised stormwater ordinance. Post-construction site inspections will be performed to identify site conditions including BMP condition, along with other site characteristics indicating whether site maintenance is required. Post-construction inspections will be required of qualifying construction and new development/ redevelopment sites. Structural and non-structural controls will require annual inspections. Annual inspection documentation will include photo documentation of critical BMP components and maintenance agreements for long-term BMP operations and maintenance.

Alabama Stormwater Partnership

The Alabama Stormwater Partnership was formed in June 2007 at the Alabama Stormwater Summit in Birmingham, AL as a way to organize watershed groups and individual citizens to enact policy change in Alabama through improvements in stormwater law, regulations, and enforcement across the state. Mobile Baykeeper is a founding member and primary coordinator of the Partnership's work.  Since its formation, the Partnership has continued advocating for stronger oversight by regulatory authorities by meeting with officials at EPA, ADEM, and local governments as well as providing comments to those agencies on stormwater regulations currently under revision. Members of the Partnership are also heavily involved in educating citizens, developers, and politicians on the problem stormwater pollution poses, primarily focusing on sources of sediment pollution in our waterways and finding ways to stop it, including Muddy Water Watch and Low Impact Design training. 

Mobile Baykeeper  has undertaken the tasks of advocating for stormwater regulatory and policy reform at both the federal and state level, educating the public on the harm to waterways from stormwater pollution, and working for increased Clean Water Act compliance by construction sites operators and other regulated entities. The goal is to reduce the impacts of construction, municipal and industrial storm water pollution in the Mobile Bay Watershed.

City of Mobile Stormwater Documents

State of Alabama STORMWATER DOCUMENTS

Alabama Handbook for Erosion Control, Sediment Control and Stormwater Management on Construction Sites and Urban Areas (Rev. No. 3 September 2014)

Runoff Conveyance...p. 93

   
  • Check Dam (CD)
  • Grass Swale (GS)
  • Riprap-lined Swale (RS)
  • Diversions (DV)
  • Lined Swale (LS)
  • Subsurface Drain (SD)
  • Drop Structure (DS)
  • Outlet Protection (OP)
  • Temporary Slope Drain (TSD)

 

Sediment Control...p. 129

 
  • Block and Gravel Inlet Protection (BIP)
  • Filter Strip (FS)
  • Brush/Fabric Barrier (BFB)
  • Floating Turbidity Barrier (FB)
  • Fabric Drop Inlet Protection (FIP)

 

Stormwater Management...p. 179

  • Bioretention Area (BA)
  • Porous Pavement (PP)
  • Stormwater Detention Basin (SDB)

 

Stream Protection...p. 197

 
  • Buffer Zone (BZ)
  • Stream Diversion Channel (SDC)
  • Channel Stabilization (CS)
  • Streambank Protection (SP)