Article I General Provisions

A decision by the Town of Denton pursuant to this chapter to allow the construction of a development to be governed by the stormwater management ordinance in effect as of May 4, 2009, in the Town of Denton.

Is distinct from a waiver granted pursuant to § 106-8 of this chapter.

APPROVAL

A documented action by the Town of Denton following a review to determine and acknowledge the sufficiency of submitted material to meet the requirements of a specified stage in the Town of Denton's review process.

Does not mean an acknowledgement by the Town of Denton that submitted material has been received for review.

FINAL PROJECT APPROVAL

Approval of the final stormwater management plan and erosion and sediment control plan required to construct a project's stormwater management facilities.

PRELIMINARY PROJECT APPROVAL

Includes securing bonding or financing for final development plans if either is required as a prerequisite for approval.

An approval as part of a local preliminary development or planning review process that includes, at a minimum:

The number of planned dwelling units or lots;

The proposed project density;

The proposed size and location of all land uses for the project;

(4)

A plan that identifies:

The proposed drainage patterns;

The location of all points of discharge from the site; and

(c)

The type, location, and size of all stormwater management measures based on site-specific stormwater management requirement computations; and

(5)

Any other information required by the Town of Denton, including, but not limited to:

The proposed alignment, location, and construction type and standards for roads, accessways, and areas of vehicular traffic;

A demonstration that the methods by which the development will be supplied with water and wastewater service are adequate; and

(c)

The size, type, and general location of all proposed wastewater and water system infrastructure.

The Town of Denton may grant an administrative waiver to a development that received a preliminary project approval prior to May 4, 2010. Administrative waivers expire according to Subsection C of this section and may be extended according to Subsection D of this section.

Expiration of administrative waivers.

Except as provided for in Subsection D of this section, an administrative waiver shall expire on:

May 4, 2013, if the development does not receive final project approval prior to that date; or

May 4, 2017, if the development receives final approval prior to May 4, 2013.

All construction authorized pursuant to an administrative waiver must be completed by May 4, 2017, or, if the waiver is extended as provided in Subsection D of this section, by the expiration of the waiver extension.

Extension of administrative waivers.

Except as provided in Subsection D(2) of this section, an administrative waiver shall not be extended.

An administrative waiver may only be extended if, by May 4, 2010, the development:

Has received a preliminary project approval; and

Was subject to a development rights and responsibilities agreement, a tax increment financing approval, or an annexation agreement.

AGRICULTURAL LAND MANAGEMENT ACTIVITIES

Administrative waivers extended according to Subsection D(2) of this section shall expire when the development rights and responsibilities agreement, the tax increment financing approval, or the annexation agreement expires.

§ 106-5 Definitions.

The following definitions are provided for the terms used in this chapter:

ADMINISTRATION

The Maryland Department of the Environment (MDE) Water and Science Administration.

ADVERSE IMPACT

Any deleterious effect on waters or wetlands, including their quality, quantity, surface area, species composition, aesthetics, or usefulness for human or natural uses which are or may potentially be harmful or injurious to human health, welfare, safety or property, to biological productivity, diversity, or stability or which unreasonably interfere with the enjoyment of life or property, including outdoor recreation.

Those methods and procedures used in the cultivation of land in order to further crop and livestock production and conservation of related soil and water resources.

APPLICANT

Any person, firm, or governmental agency who executes the necessary forms to procure official approval of a project or a permit to carry out construction of a project.

APPROVING AGENCY

The entity responsible for the review and approval of stormwater management plans.

AQUIFER

A porous, water-bearing geologic formation generally restricted to materials capable of yielding an appreciable supply of water.

BEST MANAGEMENT PRACTICE (BMP)

A structural device or nonstructural practice designed to temporarily store or treat stormwater runoff in order to mitigate flooding, reduce pollution, and provide other amenities.

CHANNEL PROTECTION STORAGE VOLUME (Cpv)

The volume used to design structural management practices to control stream channel erosion. Methods for calculating the channel protection storage volume are specified in the 2000 Maryland Stormwater Design Manual, referenced in § 106-2 of this chapter.

CLEARING

The removal of trees and brush from the land, but shall not include the ordinary mowing of grass.

CONCEPT PLAN

The first of three required plan approvals that includes the information necessary to allow an initial evaluation of a proposed project.

DESIGN MANUAL

The 2000 Maryland Stormwater Design Manual, and all subsequent revisions, that serves as the official guide for stormwater management principles, methods, and practices, referenced in § 106-2 of this chapter.

DETENTION STRUCTURE

A permanent structure for the temporary storage of runoff, which is designed so as not to create a permanent pool of water.

DEVELOP LAND

To change the runoff characteristics of a parcel of land in conjunction with residential, commercial, industrial, or institutional construction or alteration.

DIRECT DISCHARGE

The concentrated release of stormwater to tidal waters or vegetated tidal wetlands from new development or redevelopment projects in the Critical Area.

DRAINAGE AREA

That area contributing runoff to a single point measured in a horizontal plane, which is enclosed by a ridgeline.

EASEMENT

A grant or reservation by the owner of land for the use of such land by others for a specific purpose or purposes, and which shall be recorded in the land records of Caroline County, Maryland.

ENVIRONMENTAL SITE DESIGN (ESD)

Using small-scale stormwater management practices, nonstructural techniques, and better site planning to mimic natural hydrologic runoff characteristics and minimize the impact of land development on water resources. Methods for designing ESD practices are specified in the Design Manual.

EXEMPTION

Those land development activities that are not subject to the stormwater management requirements contained in this chapter.

EXTENDED DETENTION

A stormwater design feature that provides gradual release of a volume of water in order to increase settling of pollutants and protect downstream channels from frequent storm events. Methods for designing extended detention BMPs are specified in the Design Manual, referenced in § 106-2 of this chapter.

EXTREME FLOOD VOLUME (Qf)

The storage volume required to control those infrequent but large storm events in which overbank flows reach or exceed the boundaries of the one-hundred-year floodplain.

FINAL STORMWATER MANAGEMENT PLAN

The last of two required plan approvals that includes the information necessary to allow all approvals and permits to be issued by the approving agency.

FLOW ATTENUATION

Prolonging the flow time of runoff to reduce the peak discharge.

GRADING

Any act by which soil is cleared, stripped, stockpiled, excavated, scarified, filled or any combination thereof.

IMPERVIOUS AREA or IMPERVIOUS SURFACE

A surface which has been compacted or covered with a layer of material so that it is highly resistant or entirely resistant to infiltration by precipitation. It includes, but is not limited to, surfaces such as compacted clay, gravel, as well as streets, roofs, sidewalks, parking lots, and other similar surfaces.

INFILTRATION

The passage or movement of water into the soil surface.

MAXIMUM EXTENT PRACTICABLE (MEP)

Designing stormwater management systems so that all reasonable opportunities for using ESD planning techniques and treatment practices are exhausted, and only where absolutely necessary, a structural BMP is implemented.

OFF-SITE STORMWATER MANAGEMENT

The design and construction of a facility necessary to control stormwater from more than one development.

ON-SITE STORMWATER MANAGEMENT

The design and construction of systems necessary to control stormwater within an immediate development.

OVERBANK FLOOD PROTECTION VOLUME (Qp)

The volume controlled by structural practices to prevent an increase in the frequency of out-of-bank flooding generated by development. Methods for calculating the overbank flood protection volume are specified in the Design Manual, referenced in § 106-2 of this chapter.

PERSON

The federal government, the state, any county, municipal corporation, or other political subdivision of the state, or any of their units, or an individual receiver, trustee, guardian, executor, administrator, fiduciary, or representative of any kind, or any partnership, firm, association, public or private corporation, or any other entity.

PLANNING TECHNIQUES

A combination of strategies employed early in project design to reduce the impact from development and to incorporate natural features into a stormwater management plan.

RECHARGE VOLUME (Rev)

That portion of the water quality volume used to maintain groundwater recharge rates at development sites. Methods for calculating the recharge volume are specified in the Design Manual, referenced in § 106-2 of this chapter.

REDEVELOPMENT

Any construction, alteration, or improvement on sites where existing land use is commercial, industrial, institutional, or multifamily residential and existing site impervious area exceeds 40%.

RETENTION STRUCTURE

A permanent structure that provides for the storage of runoff by means of a permanent pool of water.

RETROFITTING

The construction of a structural BMP in a previously developed area, the modification of an existing structural BMP, or the implementation of a nonstructural practice to improve water quality over current conditions.

SEDIMENT

Soils or other surficial materials transported or deposited by the action of wind, water, ice, or gravity as a product of erosion.

SITE

Any tract, lot or parcel of land, or combination of tracts, lots, or parcels of land which are in one ownership or are contiguous and in diverse ownership, where development is to be performed as part of a unit, subdivision, or project.

SITE DEVELOPMENT PLAN

The second of three required plan approvals that includes the information necessary to allow a detailed evaluation of a proposed project.

STABILIZATION

The prevention of soil movement by any various vegetative and/or structural means.

STORMWATER

Water that originates from a precipitation event.

STORMWATER MANAGEMENT

For quantitative control, means a system of vegetative and structural measures that control the increased volume and rate of surface runoff caused by man-made changes to the land; and

For qualitative control, means a system of vegetative, structural, and other measures that reduce or eliminate pollutants that might otherwise be carried by surface runoff.

STORMWATER MANAGEMENT FACILITY

An individual structure through which stormwater flows, infiltrates, or discharges from a site.

STORMWATER MANAGEMENT SYSTEM

Natural areas, ESD practices, stormwater management measures, and any other structure through which stormwater flows, infiltrates, or discharges from a site.

STRIPPING

Any activity which removes the vegetative surface cover including tree removal, clearing, grubbing and storage or removal of topsoil.

TOWN

The Town of Denton.

TOWN COUNCIL

The Mayor and Council of Denton.

VARIANCE

The modification of the minimum stormwater management requirements for specific circumstances such that strict adherence to the requirements would result in unnecessary hardship and not fulfill the intent of this chapter.

WAIVER

The reduction of stormwater management requirements by the Town for a specific development on a case-by-case review basis.

WATER QUALITY VOLUME (WQv)

The volume needed to capture and treat the runoff from 90% of the average annual rainfall at a development site. Methods for calculating the water quality volume are specified in the Design Manual, referenced in § 106-2 of this chapter.

WATERCOURSE

Any natural or artificial stream, river, creek, ditch, channel, canal, conduit, culvert, drain, waterway, gully, ravine, or wash, in and including any adjacent area that is subject to inundation from overflow or floodwater.

WATERSHED

The total drainage area contributing runoff to a single point.

§ 106-6 Scope.

No person shall develop any land for residential, commercial, industrial, or institutional uses without having provided stormwater management measures that control or manage runoff from such developments, except as provided within this section. The stormwater management measures must be designed consistent with the Design Manual and constructed according to an approved plan for new development, or the policies stated in § 106-9 for redevelopment.

§ 106-7 Exemptions.

The following development activities are exempt from the provisions of this chapter and the requirements of providing stormwater management.

Agricultural land management practices;

Additions or modifications to existing single-family detached residential structures if they comply with Subsection C of this section;

Any developments that do not disturb over 5,000 square feet of land area; and

Land development activities that the Administration determines will be regulated under specific state laws, which provide for managing stormwater runoff.

§ 106-8 Waivers; watershed management plans.

Except as provided in Subsections B and D of this section, stormwater management quantitative control waivers shall be granted only to those projects within areas where watershed management plans have been developed consistent with Subsection G of this section. Written requests for quantitative stormwater management waivers shall be submitted with sufficient descriptions, drawings, and any other information that is necessary to demonstrate that ESD has been implemented to the MEP. A separate written waiver request shall be required in accordance with the provisions of this section if there are subsequent additions, extensions, or modification to a development receiving a waiver.

Except as provided in Subsection D of this section, if watershed management plans consistent with Subsection G of this section have not been developed, then stormwater management quantitative control waivers may be granted to the following projects, provided that it has been demonstrated that ESD has been implemented to the MEP:

That have direct discharges to tidally influenced receiving waters.

That are in-fill development located in a priority funding area where the economic feasibility of the project is tied to the planned density, and where implementation of the 2009 regulatory requirements would result in a loss of the planned development density, provided that:

Public water and sewer and stormwater conveyance exist;

The quantitative waiver is applied to the project for the impervious cover that previously existed on the site only;

(c)

ESD to the MEP is used to meet full water quality treatment requirements for the entire development; and

(d)

ESD to the MEP is used to provide full quantity control for all new impervious surfaces; or

When the approving agency determines that special circumstances exist that prevent the reasonable implementation of quantity control practices.

Except as provided in Subsection D of this section, stormwater management qualitative control waivers apply only to:

In-fill development projects where ESD has been implemented to the MEP and it has been demonstrated that other BMPs are not feasible;

Redevelopment projects, if the requirements of § 106-9 of this chapter are satisfied; or

Sites where the approving agency determines that special circumstances exist that prevent the reasonable implementation of ESD to the MEP.

Stormwater management quantitative and qualitative control waivers may be granted for phased development projects if a system designed to meet the 2000 regulatory requirements and the Town ordinance for multiple phases has been constructed by May 4, 2010. If the 2009 regulatory requirements cannot be met for future phases constructed after May 4, 2010, all reasonable efforts to incorporate ESD in future phases must be demonstrated.

Waivers shall only be granted when it has been demonstrated that ESD has been implemented to the MEP and must:

Be on a case-by-case basis;

Consider the cumulative effects of the Town's waiver policy; and

Reasonably ensure the development will not adversely impact stream quality.

If the Town has established an overall watershed management plan for a specific watershed, then the Town may develop quantitative waiver and redevelopment provisions that differ from §§ 106-8B and 106-9 of this chapter.

A watershed management plan developed for the purpose of implementing different stormwater management policies for waivers and redevelopment shall:

Include detailed hydrologic and hydraulic analyses to determine hydrograph timing;

Evaluate both quantity and quality management and opportunities for ESD implementation;

Include a cumulative impact assessment of current and proposed watershed development;

(4)

Identify existing flooding and receiving stream channel conditions;

(5)

Be conducted at a reasonable scale;

(6)

Specify where on-site or off-site quantitative and qualitative stormwater management practices are to be implemented;

(7)

Be consistent with the General Performance Standards for Stormwater Management in Maryland found in the Design Manual; and

(8)

Be approved by the Administration.

§ 106-9 Redevelopment.

Stormwater management plans are required by the Town for all redevelopment, unless otherwise specified by watershed management plans developed according to § 106-8F and G of this chapter. Stormwater management measures must be consistent with the Design Manual.

All redevelopment projects shall:

Reduce impervious area within the limit of disturbance (LOD) by at least 50% according to the Design Manual;

Implement ESD to the MEP to provide water quality treatment for at least 50% of the existing impervious area within the LOD; or

Use a combination of Subsection B(1) and (2) of this section for at least 50% of the existing site impervious area.

Alternative stormwater management measures may be used to meet the requirements in Subsection B of this section if the owner/developer satisfactorily demonstrates to the Town that impervious area reduction has been maximized and ESD has been implemented to the MEP. Alternative stormwater management measures may include, but are not limited to:

An on-site structural BMP;

An off-site structural BMP to provide water quality treatment for an area equal to or greater than 50% of the existing impervious area within the LOD; or

A combination of impervious area reduction, ESD implementation, and an on-site or off-site structural BMP for an area equal to or greater than 50% of the existing impervious area within the LOD.

The Town may adopt separate policies in the future, subject to Administration approval, for redevelopment projects if the requirements of Subsections B and C of this section cannot be met. Any separate redevelopment policy shall be reviewed and approved by the Administration and may include, but not be limited to:

A combination of ESD and an on-site or off-site structural BMP;

Retrofitting including existing BMP upgrades, filtering practices, and off-site ESD implementation;

Participation in a stream restoration project;

(4)

Pollution trading with another entity;

(5)

Payment of a fee-in-lieu; or

(6)

A partial waiver of the treatment requirements if ESD is not practicable.

The determination of what alternatives will be available may be made by the Town at the appropriate point in the development review process. The Town shall consider the prioritization of alternatives in Subsection D of this section after it has been determined that it is not practicable to meet the 2009 regulatory requirements using ESD. In deciding what alternatives may be required, the Town may consider factors, including, but not limited to:

Whether the project is in an area targeted for development incentives such as a priority funding area, a designated transit-oriented development area, or a designated base realignment and closure revitalization and incentive zone;

Whether the project is necessary to accommodate growth consistent with comprehensive plans; or