§ 17.10.100. Stormwater management plans.

A.

Review and Approval of Stormwater Management Plans.

1.

Unless otherwise exempted, for any proposed development, the owner or his/her agent shall submit to the Department of Public Works for review and approval, phased stormwater management plans or waiver application as part of the grading permit application. At a minimum, plans shall be submitted for the concept, site development, and final stormwater management construct phases of project design. The stormwater management plan shall contain supporting computations, drawings, and sufficient information describing the manner, location, and type of measures in which stormwater runoff from the entire development will be managed, and shall be consistent with the requirement of the Design Manual. The Department of Public Works shall review the plans to determine compliance with the requirements of this chapter prior to approval. The plans shall serve as the basis for all subsequent construction.

2.

The Department of Public Works 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 reflects input from all appropriate agencies including, but not limited to, the Anne Arundel County Soil Conservation District (SCD) and the Departments of Planning and Zoning. All comments from other appropriate agencies shall be addressed and approval received at each phase of project design before subsequent submissions.

3.

Issuance of the grading permit shall constitute approval of the Stormwater Management Plan for construction.

B.

Contents and Submission of the Stormwater Management Plan.

1.

The owner/developer shall submit a concept plan that provides sufficient information for an initial assessment of the proposed project and whether stormwater management can be provided according to Section 17.10.080 of this Ordinance and the Design Manual. Plans submitted for concept approval shall include, but are not limited to:

a.

A map at a scale specified by the Department of Public Works showing site location, existing natural features, water and other sensitive resources, topography, and natural drainage patterns at a scale of 1:10, 1:20 or 1:50;

b.

The anticipated location of all proposed impervious areas, buildings, roadways parking, sidewalks, utilities, and other site improvements;

c.

The location of the proposed limit of disturbance, erodible soils, steep slopes, and areas to be protected during construction;

d.

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;

e.

A narrative that supports the concept design and describes how ESD will be implemented to the MEP; and

f.

Any other information required by the Department of Public Works.

2.

Following concept plan approval by the Department of Public Works, 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:

a.

All information provided during the concept plan review phase;

b.

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;

c.

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;

d.

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

e.

Any other information required by the approving agency.

3.

Following site development approval by the Department of Public Works, 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:

a.

Final erosion and sediment control plans shall be submitted according to COMAR 26.17.01.05; and

b.

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.

4.

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

a.

Geotechnical investigations including soil maps, borings, site specific recommendations, and any additional information necessary for the final stormwater management design;

b.

Drainage area maps depicting predevelopment and post development runoff flow path segmentation and land use;

c.

Hydrologic computations of the applicable ESD and unified sizing criteria according to the Design Manual for all points of discharge from the site;

d.

Hydraulic and structural computations for all ESD practices and structural stormwater management measures to be used;

e.

A narrative that supports the final stormwater management design; and

f.

Any other information required by the Department of Public Works.

5.

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

a.

A vicinity map;

b.

Existing and proposed topography and proposed drainage areas, including areas necessary to determine downstream analysis for proposed stormwater management facilities;

c.

Any proposed improvements including location of buildings or other structures, impervious surfaces, storm drainage facilities, and all grading;

d.

The location of existing and proposed structures and utilities;

e.

Any easements and rights-of-way;

f.

The delineation, if applicable, of the one hundred-year floodplain, on-site wetlands or Critical Area designation and one hundred-foot buffer;

g.

Structural and construction details including representative cross sections for all components of the proposed drainage system or systems, and stormwater management facilities;

h.

All necessary construction specifications;

i.

A sequence of construction;

j.

Data for total site area, disturbed area, new impervious area, and total impervious area;

k.

A table showing ESD and unified sizing criteria volumes required in the Design Manual;

l.

A table of materials to be used for stormwater management facility planting;

m.

All soil borings logs and locations;

n.

An inspection and maintenance schedule;

o.

Certification by the owner/developer that all stormwater management construction will be done according to this plan;

p.

An as-built certification signature block to be executed after project completion; and

q.

Any other information required by the Department of Public Works.

C.

Preparation of the Stormwater Management Plan.

1.

The stormwater management plan shall be prepared under the general supervision of a professional engineer registered to practice in the State of Maryland. The professional engineer and any other design professional involved in the preparation of any stormwater management plan submitted to the Department of Public Works, shall sign and seal the plan.

2.

If a stormwater management plan requires either a dam safety permit from the Maryland Department of Environment or a small pond approval from the Anne Arundel Soil Conservation District, then the dam and/or pond design shall be prepared, signed and sealed by a professional engineer registered to practice in the State of Maryland.

D.

Design Requirements.

1.

Stormwater management facilities shall be designed to minimize the need of maintenance, to provide access for maintenance purposes and to be structurally sound. Additionally, a stormwater management facility shall be designed in accordance with standard construction specifications and details established and promulgated by the Department of Public Works.

2.

Prior to approval of a stormwater management design, the applicant shall submit a proposed staged inspection and construction control schedule. The schedule shall provide for regular inspections by a registered professional engineer to be conducted during construction of stormwater management systems in accordance with accepted engineering practices.

3.

The permittee shall notify the Department of Public Works before commencing any work to implement the stormwater management plan and upon completion of the work.

4.

No stage of work involving the installation of stormwater management facilities shall proceed until the work previously completed is inspected and approved by the Department of Public Works.

5.

Any portion of the work that does not comply with the stormwater management plan shall be corrected promptly by the permittee.

6.

A final inspection shall be conducted by the Department of Public Works upon completion of the stormwater management facility to determine if the completed work is constructed in accordance with the approved stormwater management plan. The final inspection by the Department of Public Works does not relieve the permittee of any of requirement imposed on the permittee by this chapter.

E.

Construction Compliance. Archive able and reproducible as-built plans of the stormwater management facility shall be forwarded to the Department of Public Works upon completion of the stormwater management facility and final inspection by the Department of Public Works The permittee's professional engineer shall certify that the stormwater management facility has been constructed as shown on the as-built plans and that the stormwater management facility meets the approved stormwater management plan's design and specifications.

F.

Electronic Documentation. The Director of Public Works may require the permittee and his/her engineer to submit all of the documents associated with the grading permit in an electronic format for archiving purposes. The documents shall be submitted in the format required by the Director of Public Works.

G.

Release of Security. The performance bond shall not be reduced nor released until all aspects of the stormwater management plan are completed, including, but not limited to:

1.

The submission and acceptance of "as built drawings" in accordance with Subsection E of this section,

2.

The completion of all forms required by the administration, and

3.

The stormwater management facility has been in operation for a minimum of one year without failure.

(Ord. O-26-03 § 1 (part): Ord. O-10-02 § 1 (part))

(Ord. No. O-59-09, § I, 12-21-2009; Ord. No. O-26-10, § I, 9-13-2010; Ord. No. O-12-16 Amended, § I, 5-23-2016)