17.52.010 Authority

The provisions contained in this chapter are adopted to comply with the requirements contained in the General Permit for Storm Water Discharge Associated with Small Municipal Separate Storm Sewer System (MS4) issued by the Montana Department of Environmental Quality to the City of Great Falls, most recent edition, and the City of Great Falls Storm Design Manual, June 1990, as amended.

17.52.020 Legislative findings

The City Commission makes the following findings:

1. Land development projects and associated increases in impervious cover can alter the hydrologic response of local watersheds and increase stormwater runoff rates and volumes.
2. High levels of stormwater runoff can cause flooding, stream channel erosion, and sediment transport/deposition.
3. Stormwater runoff contributes to increased quantities of water-borne pollutants.

17.52.030 Purpose

This chapter is established to promote the public health, safety, and welfare and is intended to accomplish the following purposes:

1. promote sound development policies and construction procedures
2. minimize water quality degradation
3. minimize the sedimentation of waterbodies
4. minimize adverse impacts on property owners adjacent to developing and developed land from increased runoff
5. promote the stability of existing streambanks and channels
6. preserve and enhance the aesthetic quality of waterbodies
7. maintain and protect valuable groundwater resources
8. minimize the thermal warming of receiving waters from stormwater discharges
9. reduce stormwater damage to public and private property
10. ensure that all stormwater facilities, once constructed, are properly maintained to ensure long-term effectiveness

17.52.040 Applicability

1. Generally. This chapter applies to any parcel that has or will have an impervious surface of more than 15,000 square feet. B. Exemptions. The following are exempt:
   1. a single-family structure on a single lot, including new construction and additions
   2. any emergency activity that is immediately necessary for the protection of life, property, or natural resources
   3. any project within the central business district
2. Waivers. The Director of Public Works may waive the requirements of this chapter, in whole or in part, upon written request, provided that at least one of the following conditions applies:
   1. alternative minimum requirements for on-site management of stormwater discharges have been established in a stormwater management plan which has been approved by the City Commission
   2. provisions are made to manage stormwater by an off-site facility that provides 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
3. Director of Public Works. In this Chapter, the term “Director of Public Works” shall refer to the Director of Public Works of the City of Great Falls or his/her designee

17.52.050 Land dedications and fee in lieu payments

1. Fee in lieu. When the Director of Public Works waives all or part of the stormwater management requirements, or where the waiver is based on the provision of adequate stormwater facilities provided downstream of the proposed development, the applicant shall be required to pay the City a fee. The monetary contribution shall be in accordance with a fee schedule (unless the developer and the director agree on a greater alternate contribution), based on the cubic feet of storage required for stormwater management of the development in question or on a cost per acre basis (construction costs divided by acres served). Monetary contributions shall be credited to an appropriate capital improvements program project for the Storm Drain Fund, and shall be made by the developer prior to the issuance of any building permit for the development.
2. Dedication of land. In lieu of a monetary contribution, the City may, in its discretion, accept an easement or dedicated land from the applicant for the construction of an off-site stormwater management facility. The agreement regarding the easement or dedication may be entered into by the applicant and the City prior to the recording of plats or, if no record plat is required, prior to the issuance of a building permit.

17.52.060 Credit for construction of improvements

If the storm drainage utility requires a developer to construct storm drainage facilities that serve more than that development and are identified in a storm drain master plan, a portion of the actual costs incurred may be eligible for reimbursement from the Storm Drain Fund and/or future development. To be eligible for reimbursement, prior to final approval of the development agreement, the developer must submit to the storm drainage utility a report detailing the proposed improvements and obtain the City's approval of the report. The report must identify all elements of the project eligible for reimbursement and include a detailed project description, a project bid form with estimated quantities, unit prices, engineering design, and construction management costs. The report must also provide an accurate quantity and cost delineation between the proposed storm drainage improvements necessary to meet the standard requirements of the development and those that are not. The books and records of the developer relating to the storm drainage facilities for which the utility is providing reimbursement shall be open to the City at all reasonable times for the purpose of audit and/or verification of costs.

17.52.070 Responsibility for accepted facilities

All storm drainage facilities installed consistent with this chapter within City-owned land shall, upon acceptance by the Director of Public Works, become the property of the City. The City shall maintain and operate all accepted public storm drainage facilities located within City-owned land, City rights-of-way, and City easements. The City has the option to maintain other public storm drainage facilities located within or adjacent to the City. Such other public facilities include, open drainage ways and piped drainage ways constructed expressly for use by the general public and as a part of the City storm drainage facilities, bridges, roadside drainage ditches and gutters, and flood control facilities, including detention and retention basins, dikes, overflow channels, pump stations, etc., that have been designed and constructed expressly for use by the public. Such public storm drainage facilities exclude facilities expressly rejected by the City for maintenance.

17.52.080 Technical standards and specifications

1. Flow calculations. Flow calculations shall be based on the City’s stormwater manual.
2. Best management practices. The City’s stormwater manual and DEQ General Permit shall be used in complying with this chapter. Supplemental material is available from the EPA's Menu of BMPs, which is posted on the EPA’s website. This web-site includes a list of acceptable stormwater treatment practices, including the specific design criteria and operation and maintenance requirements for each. The website may be updated and expanded in the future based on improvements in engineering, science, monitoring, and local maintenance experience. Stormwater treatment practices that are designed and constructed in accordance with these design and sizing criteria will be presumed to meet minimum performance standards.

17.52.090 General performance standards

1. Peak discharge rate. Stormwater management practices shall be designed in accordance with the City’s stormwater manual.
2. Stormwater discharge to a wetland. All stormwater runoff generated from new development shall not discharge untreated stormwater directly into a jurisdictional wetland or local waterbody without adequate treatment. Where such discharges are proposed, the impact of the proposal on wetland functional values shall be assessed using a method acceptable to the Director of Public Works. In no case shall the impact on functional values be any less than allowed by the Army Corp of Engineers (ACE) or the Montana Department of Environmental Quality.
3. Discharge to sensitive resources. Stormwater discharges to critical areas with sensitive resources (e.g., cold water fisheries) may be subject to additional performance criteria, or may need to utilize or restrict certain stormwater management practices.
4. Discharges from “hotspots”. Stormwater discharges from land uses or activities with higher potential pollutant loadings, known as “hotspots”, may require the use of additional structural stormwater treatment practices and pollution prevention practices.
5. Additional requirements. Prior to design, applicants are required to consult with the Director of Public Works to determine if they are subject to additional stormwater design requirements.

17.52.100 Maintenance agreements

1. Generally. All private stormwater treatment practices/facilities shall have an enforceable operation and maintenance agreement with the City and other applicable parties to ensure the system functions properly.
2. Contents of agreement. This agreement shall at a minimum include the following provisions:
   1. The agreement shall run with the land and is binding on all property owners served by the practice/facility.
   2. The agreement includes an easement, as may be required, to access and inspect the practice/facility, and to perform work as necessary to ensure the system functions properly.
   3. The agreement shall include a long-term maintenance schedule and specifications to ensure the system functions properly.
   4. A qualified individual shall inspect the practice/facility on an annual basis to document maintenance and repair needs and ensure compliance with the requirements of this chapter.
   5. Any maintenance needs found must be addressed in a timely manner.
   6. The agreement grants the Director of Public Works the right of physical access to the practice/facility for periodic inspections and corrective actions as may be appropriate.
   7. If the practice/facility serves more than one parcel, the agreement shall have a formal mechanism for sharing in the cost of maintenance.
   8. Copies of all reports/inspections shall be submitted to the Director of Public Works within 10 days of completion.
   9. The Director of Public Works may impose additional requirements to ensure the practice/facility functions properly.
   10. Failure to meet the terms of the agreement constitutes a violation of the land development code.
   11. The agreement can only be terminated with written approval of the Director of Public Works when the practice/facility is no longer needed.
   12. The responsible party shall keep a copy of all reports and maintenance records for a period of 10 years.
3. Recordation. The agreement, as approved by the Director of Public Works, shall be recorded in the official records of the County Clerk and Recorder.

17.52.110 Performance bond/security

The Director of Public Works may require the submittal of a performance security or bond consistent with Chapter 68 of this Title prior to issuance of a permit in order to ensure that the stormwater practices are installed consistent with the approved stormwater permit or management plan.

17.52.120 Construction inspection

The applicant must notify the Director of Public Works prior to commencement of construction. The director shall conduct inspections as may be appropriate to ensure compliance with the approved permit. All inspections shall be documented with a written report that contains the following information:

1. date and location of the inspection
2. name of inspector
3. whether construction is in compliance with the approved stormwater management plan
4. variations from the approved construction specifications
5. any violations that exist

If any violations are found, the requirements of Chapter 16 of this Title shall be followed.

17.52.130 As-built plans

As-built plans shall be submitted to the Public Works Department following completion of the stormwater facility. The plan must show the final design specifications and must be certified by a professional engineer.

17.52.140 Public dedication of facilities

Consistent with Chapter 68 of this Title, the City Commission may accept the dedication of any existing or future stormwater management facility for maintenance and operation, provided such facility meets all the requirements of this chapter and includes adequate and perpetual access and sufficient area, by easement or otherwise, for inspection and regular maintenance.

17.52.150 Inspection of stormwater facilities

The City may establish inspection programs on any reasonable basis, including but not limited to: routine inspections; random inspections; inspections based upon complaints or other notice of possible violations; inspection of drainage basins or areas identified as higher than typical sources of sediment or other contaminants or pollutants; inspections of businesses or industries of a type associated with higher than usual discharges of contaminants or pollutants or with discharges of a type which are more likely than the typical discharge to cause violations of State or federal water or sediment quality standards or the NPDES stormwater permit; and joint inspections with other agencies inspecting under environmental or safety laws. Inspections may include, but are not limited to: reviewing maintenance and repair records; sampling discharges, surface water, groundwater, and material or water in drainage control facilities; and evaluating the condition of drainage control facilities and other stormwater treatment practices.

17.52.160 Records of installation and maintenance activities

Parties responsible for the operation and maintenance of a stormwater management facility shall make records of the installation and of all maintenance and repairs, and shall retain them for at least 10 years. These records shall be made available to the City during inspection of the facility and at other reasonable times upon request.