City of Hagerstown

Stormwater management within the City of Hagerstown is provided by a number of facilities both public and private. Various stormwater best management practices (BMPs) are used around the City. While some sites have BMPs already in place to provide the necessary control, other sites require the construction of the necessary facilities as part of site development. Typically, structures which serve residential areas are owned and maintained by a homeowners association. Structures which serve commercial / industrial areas are owned and maintained by either the property owner or developer. City-owned business parks are typically maintained by the City.

The City’s Stormwater Management Program seeks to not only mitigate flooding and runoff-related damage, but also to improve water quality in the Chesapeake Bay, the Potomac River, and all of the tributaries in Washington County. The City’s Stormwater Management Ordinance establishes the stormwater quality and quantity requirements for both new developments, as well as previously constructed sites that are being redeveloped. The City has also developed a program to comply with its National Pollutant Discharge Elimination System Permit issued by the Environmental Protection Agency.

Excerpts from the City of Hagerstown Stormwater Management Ordinance

ARTICLE IV STORMWATER MANAGEMENT CRITERIA

213.11 Minimum Control Requirements

The minimum control requirements established in this section and the Design Manual are as follows:

The planning techniques, nonstructural practices, and design methods specified in the Design Manual be used to implement ESD to the MEP. The use of ESD planning techniques and treatment systems must be exhausted before any structural BMP is implemented. Stormwater management plans for development projects subject to this Chapter shall be designed using ESD sizing criteria, recharge volume, water quality volume, and channel protection storage volume criteria according to the Design Manual. The MEP standard is met when channel stability is maintained, predevelopment groundwater recharge is replicated without causing damage or unduly endangering the water quality of the underlying aquifer, nonpoint source pollution is minimized, and structural stormwater management practices are used only if determined to be absolutely necessary.
Control of the 2-year and 10-year frequency storm event is required according to the Design Manual and all subsequent revisions unless the City Engineer determines that additional stormwater management is necessary because historical flooding problems exist downstream.
The extreme flood volume calculated for the 100-year frequency storm event shall be used as sizing criteria if so directed by the City Engineer. However, this requirement may be waived if the owner/developer demonstrates that implementing the extreme flood volume will actually cause detrimental impacts downstream. As a minimum, any structural BMP’s proposed shall convey the runoff for the 100-year storm event through the BMP structure without causing unacceptable damage and/or flooding to the subject property or surrounding properties. Undeveloped offsite areas contributing runoff to the point of study, if not under the direct control of the owner/developer performing the analysis, shall be treated as being developed in accordance with the zoning designation for those lands for the 100-year analysis.
The City Engineer may require more than the minimum control requirements specified in this Chapter if hydrologic or topographic conditions warrant, or if flooding, stream channel erosion, or water quality problems exist downstream from a proposed project. The extent of a downstream area that is subject to the requirements stated herein will vary depending upon the location, and will be established with the concurrence of the City Engineer.

Alternate minimum control requirements may be adopted subject to Administration approval. The Administration shall require a demonstration that alternative requirements will implement ESD to the MEP and control flood damages, accelerated stream erosion, water quality, and sedimentation. Comprehensive watershed studies may also be required.

Stormwater management and development plans where applicable, shall be consistent with adopted and approved watershed management plans or flood management plans as approved by the Maryland Department of the Environment in accordance with the Flood Hazard Management Act of 1976.

Should, in the opinion of the City Engineer, downstream deficiencies require stormwater management criteria in excess of the minimums identified in this Chapter, the City Engineer may direct or the owner/developer may elect to correct the noted deficiencies in order the obtain relief from the more stringent criteria. However, nothing in this section shall be considered as waiving the need for a development to comply with the minimum requirements identified in this Chapter.

213.12 Stormwater Management Measures

The ESD planning techniques and practices and structural stormwater management measures established in this Chapter and the Design Manual shall be used, either alone or in combination in a stormwater management plan. A developer shall demonstrate that ESD has been implemented to the MEP before the use of a structural BMP is considered in developing the stormwater management plan.

ESD Planning Techniques and Practices.

The following planning techniques shall be applied according to the Design Manual to satisfy the applicable minimum control requirements established in Section 213.11 of this Chapter:

Preserving and protecting natural resources;
Conserving natural drainage patterns;
Minimizing impervious area;
Reducing runoff volume;
Using small-scale ESD practices to maintain 100 percent of the annual predevelopment groundwater recharge volume, subject to the limitations for stormwater management and infiltration practices in Karst areas as defined in Appendix D.2 of the Design Manual.
Using green roofs, permeable pavement, reinforced turf, and other alternative surfaces, subject to the restrictions listed in 213.12.A.(2) below.
Limiting soil disturbance, mass grading, and compaction;
Clustering development; and
Any practices approved by the Administration.

The following ESD treatment practices shall be designed according to the Design Manual to satisfy the applicable minimum control requirements established in Section 213.11 of this Chapter. However, for any proposed practice that relies upon infiltration to discharge stormwater from the site, the owner/developer must demonstrate to the City Engineer’s satisfaction that such infiltration can be accomplished without causing damage to existing or proposed structures and features, and with minimal degradation to the aquifer underlying the site.
1. Disconnection of rooftop runoff;
2. Disconnection of non-rooftop runoff;
3. Sheetflow to conservation areas;
4. Rainwater harvesting;
5. Submerged gravel wetlands;
6. Landscape infiltration;
7. Infiltration berms;
8. Micro-bioretention;
9. Rain gardens;
10. Swales;
11. Enhanced filters; and
12. Any practices approved by the Administration.

The use of ESD planning techniques and treatment practices specified in this section shall not conflict with existing State law or local ordinances, regulations, or policies. The City shall modify planning and zoning ordinances and public works codes to eliminate any impediments to implementing ESD to the MEP according to the Design Manual.

Structural Stormwater Management Measures.

The following structural stormwater management practices shall be designed according to the Design Manual to satisfy the applicable minimum control requirements established in Section 213.11 of this Chapter:
1. Stormwater management ponds;
2. Stormwater management wetlands;
3. Stormwater management infiltration, subject to the approval of the City Engineer, and taking into consideration the issues identified in Section 213.12.B(3) below;
4. Stormwater management filtering systems incorporating underdrains, unless the underdrain requirement is waived by the City Engineer; and
5. Stormwater management open channel systems.

The performance criteria specified in the Design Manual with regard to general feasibility, conveyance, pretreatment, treatment and geometry, environment and landscaping, and maintenance shall be considered when selecting structural stormwater management practices.

Structural stormwater management practices shall be selected to accommodate the unique hydrologic or geologic regions of the State. When selecting structural BMP’s, special attention is directed to the existence of Karst geology within Washington County, and the influence these areas have on acceptable means for stormwater management. Refer to the Design Manual for specific guidelines.

The design engineer and the owner/developer are responsible for considering safety and access to all proposed facilities. The Design Manual includes several possible design safety considerations. Measures to be considered may include fencing, slope benching, flattened side slopes, access roads, etc. Permanent pools greater than two (2) feet in depth, or structures with 100-year ponding depths greater than four feet shall incorporate appropriate safety measures, approved by the City Engineer.

ESD planning techniques and treatment practices and structural stormwater management measures used to satisfy the minimum requirements in Section 213.11 of this Chapter must be recorded in the land records of Washington County and remain unaltered by subsequent property owners. Prior approval from the City Engineer shall be obtained before any stormwater management practice is altered.

Alternative ESD planning techniques and treatment practices and structural stormwater measures may be used for new development runoff control if they meet the performance criteria established in the Design Manual and all subsequent revisions, and are approved by the City Engineer and the Administration. Practices used for redevelopment projects shall be approved by the City Engineer.

213.13 Specific Design Criteria

The basic design criteria, methodologies, and construction specifications, subject to the approval of the City Engineer and the Administration, shall be those of the Design Manual.

ARTICLE V STORMWATER MANAGEMENT PLANS

213.14 Review and Approval of Stormwater Management Plans

For any proposed development with a disturbed area greater than 15,000 square feet (i.e. any development that is not covered by a Standard Erosion and Sediment Control Plan issued by the Washington County Conservation District), the owner/developer shall submit phased stormwater management plans to the City for review and approval. At a minimum, plans shall be submitted for the concept, site development, and final stormwater management construction phases of project design. Each plan submittal shall include the minimum content specified in Section 213.15 of this Chapter and meet the requirements of the Design Manual and Sections 213.11 and 213.12 of this Chapter.

For proposed developments with a disturbed area less than or equal to 15,000 square feet, the City’s Zoning Administrator shall have the discretion to allow the owner/developer to submit a concept plan and a combined site development/final stormwater management construction plan. However, both the concept plan and the combined site development/final stormwater management plan must still meet the minimum content specified in Section 213.15, and meet the requirements of the Design Manual and Sections 213.11 and 213.12 of this Chapter.

The City shall perform a comprehensive review of the stormwater management plans for each phase of site design. Coordinated comments will be provided for each plan phase that reflect input from all appropriate agencies including, but not limited to the Soil Conservation District (SCD) and the departments of Planning, Engineering, Public Works, Utilities, and the Fire Marshall. All comments from the City and other appropriate agencies shall be addressed and approval received at each phase of project design before subsequent submissions.

213.15 Contents and Submission of Stormwater Management Plans

The owner/developer shall submit a concept plan to the City Planning Department that provides sufficient information for an initial assessment of the proposed project and whether stormwater management can be provided according to Section 213.11 of this Chapter and the Design Manual. Plans submitted for concept approval shall include, but are not limited to

A map at a scale specified by the City showing site location, existing natural features, water and other sensitive resources, surface rock outcroppings, topography, and natural drainage patterns;
The anticipated location of all proposed impervious areas, buildings, roadways, parking, sidewalks, utilities, and other site improvements;
The location of the proposed limit of disturbance, erodible soils, steep slopes, and areas to be protected during construction;
Preliminary estimates of stormwater management requirements, the selection and location of ESD practices to be used, and the location of all points of discharge from the site;
A narrative that supports the concept design and describes how ESD will be implemented to the MEP; and
Any other information required by the approving agency.

Following concept plan approval by the City, the owner/developer shall submit site development plans that reflect comments received during the previous review phase. Plans submitted for site development approval shall be of sufficient detail to allow site development to be reviewed and include but not be limited to:

All information provided during the concept plan review phase;
Final site layout, exact impervious area locations and acreages, proposed topography, delineated drainage areas at all points of discharge from the site, and stormwater volume computations for ESD practices and quantity control structures;
A proposed erosion and sediment control plan that contains the construction sequence, any phasing necessary to limit earth disturbances and impacts to natural resources and an overlay plan showing the types and locations of ESD and erosion and sediment control practices to be used;

A narrative that supports the site development design, describes how ESD will be used to meet the minimum control requirements, and justifies any proposed structural stormwater management measure; and
Any other information required by the approving agency.

Following site development approval by the City, the owner/developer shall submit final erosion and sediment control and stormwater management plans that reflect the comments received during the previous review phase. Plans submitted for final approval shall be of sufficient detail to allow all approvals and permits to be issued according to the following:

Final erosion and sediment control plans shall be submitted according to COMAR 26.17.01.05; and
Final stormwater management plans shall be submitted for approval in the form of construction drawings and be accompanied by a report that includes sufficient information to evaluate the effectiveness of the proposed runoff control design.

Reports submitted for final stormwater management plan approval shall include, but are not limited to:

Geotechnical investigations including soil maps, borings, site specific recommendations, and any additional information necessary for the final stormwater management design;
Drainage area maps depicting predevelopment and post development runoff flow path segmentation and land use;
Hydrologic computations of the applicable ESD and unified sizing criteria according to the Design Manual for all points of discharge from the site;
Hydraulic and structural computations for all ESD practices and structural stormwater management measures to be used;
A narrative that supports the final stormwater management design;
The seal and signature of the Professional Engineer that prepared the report; and
Any other information required by the City.

Construction drawings submitted for final stormwater management plan approval shall include, but are not limited to:
1. A vicinity map;
2. Existing and proposed topography and proposed drainage areas, including areas necessary to determine downstream analysis for proposed stormwater management facilities;
3. Any proposed improvements including location of buildings or other structures, impervious surfaces, storm drainage facilities, and all grading;
4. The location of existing and proposed structures and utilities;
5. Any easements and rights-of-way;
6. The delineation, if applicable, of the 100-year floodplain and any on-site wetlands;
7. Structural and construction details including representative cross sections for all components of the proposed drainage system or systems, and stormwater management facilities;
8. All necessary construction specifications;
9. A sequence of construction;
10. Data for total site area, disturbed area, new impervious area, and total impervious area;
11. A table showing the ESD and unified sizing criteria volumes required in the Design Manual;
12. A table of materials to be used for stormwater management facility planting;
13. All soil boring logs and locations;
14. An inspection and maintenance schedule, with specific maintenance instructions to be followed by the owner of the facilities;
15. Certification by the owner/developer that all stormwater management construction will be done according to this plan;
16. An as-built certification signature block to be executed by the Certifying Engineer after project completion; and
17. Any other information required by the City.

If a stormwater management plan involves direction of some or all runoff off of the site, it is the responsibility of the developer to obtain from adjacent property owners any easements or other necessary property interests concerning flowage of water. Approval of a stormwater management plan does not create or affect any right to direct runoff onto adjacent property without that property owner's permission.

213.16 Preparation of Stormwater Management Plans

The design of stormwater management plans shall be prepared by any individual whose qualifications are acceptable to the City Engineer. The City Engineer may require that the design be prepared by either a professional engineer, professional land surveyor, or landscape architect licensed in the State, as necessary to protect the public or the environment.
If a stormwater BMP requires either a dam safety permit from MDE or small pond approval from the Washington County Conservation District, the City shall require that the design be prepared by a professional engineer licensed in the State.

ARTICLE VIII INSPECTIONS

213.22 Inspection Schedule and Reports

The developer shall notify the City Engineer at least 48 hours before commencing any work in conjunction with site development, the stormwater management plan, and upon completion of the project.

Regular inspections shall be made and documented for each ESD planning technique and practice at the stages of construction specified in the Design Manual by the Certifying Engineer. At a minimum, all ESD and other nonstructural practices shall be inspected upon completion of final grading, the establishment of permanent stabilization, and before issuance of use and occupancy approval.

Written inspection reports shall include:

The date and location of the inspection;
Whether construction was in compliance with the approved stormwater management plan;
Any variations from the approved construction specifications; and
Any violations that exist.

The owner/developer and on-site personnel shall be notified in writing when violations are observed. Written notification shall describe the nature of the violation and the required corrective action.

No work shall proceed on the next phase of development until the Certifying Engineer inspects and approves the work previously completed, and furnishes the City Engineer and the owner/developer with, at a minimum, the inspection reports required in Sections 213.22 B & C as soon as possible after completion of each required inspection.

ARTICLE IX MAINTENANCE

213.24 Maintenance Inspection

The City shall ensure that preventative maintenance programs are in place for all ESD treatment systems and structural stormwater management measures. Inspection shall occur during the first year of operation and at least once every 3 years thereafter. In addition, a maintenance agreement between the owner and the City shall be executed for privately-owned ESD treatment systems and structural stormwater management measures as described in Section 213.25 of this Chapter.

Inspection reports shall be maintained by the City for all ESD treatment systems and structural stormwater management measures.

Inspection reports for ESD treatment systems and structural stormwater management measures shall include the following:
1. The date of inspection;
2. Name of inspector;
3. An assessment of the quality of the stormwater management system related to ESD treatment practice efficiency and the control of runoff to the MEP;
4. The condition of:
  1. Vegetation or filter media;
  2. Fences or other safety devices;
  3. Spillways, valves, or other control structures;
  4. Embankments, slopes, and safety benches;
  5. Reservoir or treatment areas;
  6. ) Inlet and outlet channels or structures;
  7. Underground drainage;
  8. Sediment and debris accumulation in storage and forebay areas;
  9. Any nonstructural practices to the extent practicable; and
  10. Any other item that could affect the proper function of the stormwater management system.
Description of needed maintenance.

Upon notifying an owner of the inspection results, the owner shall have 30 days, or other time frame mutually agreed to between the City and the owner, to correct the deficiencies discovered. The City shall conduct a subsequent inspection to ensure completion of the repairs.

If repairs are not properly undertaken and completed, enforcement procedures following section 213.25 C of this Chapter shall be followed by the City.

If, after an inspection by the City, the condition of a stormwater management facility is determined to present an immediate danger to public health or safety because of an unsafe condition, improper construction, or poor maintenance, the City shall take such action as may be necessary to protect the public and make the facility safe. Any cost incurred by the City shall be assessed against the owner(s), as provided in Section 213.25 C of this Chapter.

213.25 Maintenance Agreement

Prior to the issuance of any building permit for which stormwater management is required, the City shall ensure that an inspection and maintenance agreement binding on all current (and all subsequent) owners of land served by a private stormwater management facility is in place. This agreement shall either be a document completed and executed by the applicant or owner, or shall be in the form of inspection and maintenance requirements or covenants listed on a recorded subdivision plat for the subject property. Such agreements and/or covenants shall provide for access to the facility at reasonable times for regular inspections by the City or its authorized representative to ensure that the facility is maintained in proper working condition to meet design standards.

The agreement, or the subdivision plat containing the inspection and maintenance requirements, shall be recorded by the applicant or owner in the land records of Washington County.

The agreement shall also provide that, if after notice by the City to correct a violation requiring maintenance work, satisfactory corrections are not made by the owner(s) within 30 days, the City may perform all necessary work to place the facility in proper working condition. The owner(s) of the facility shall be assessed the cost of the work and any penalties. This may be accomplished by placing a lien on the property, which may be placed on the tax bill and collected as ordinary taxes by the City.

213.26 Maintenance Responsibility

The owner of a property that contains private stormwater management facilities installed pursuant to this Chapter, or any other person or agent in control of such property, shall maintain in good condition and promptly repair and restore all ESD treatment systems, grade surfaces, walls, drains, dams and structures, vegetation, erosion and sediment control measures, and other protective devices in perpetuity. Such repairs or restoration and maintenance shall be in accordance with previously approved or newly submitted plans.

A maintenance schedule shall be developed for the life of any structural stormwater management facility or system of ESD treatment systems and shall state the maintenance to be completed, the time period for completion, and the responsible party what will perform the maintenance. This maintenance schedule shall be printed on the approved stormwater management plan.