Stormwater runoff can carry pollutants into Hempstead Harbor, degrading water quality and affecting finfish and shellfish production.

The increase in nutrients such as phosphorus and nitrogen accelerates eutrophication of freshwater bodies and Hempstead Harbor, adversely affecting flora and fauna.

Improperly channeling of water increases the velocity of runoff, thereby increasing erosion and sedimentation.

Construction requiring the alteration of natural topography and removal of vegetation tends to increase erosion.

Siltation of freshwater bodies and Hempstead Harbor resulting from increased erosion decreases their capacity to hold and transport water, interferes with navigation, and harms flora and fauna.

Impervious surfaces increase the volume and rate of stormwater runoff and allow less water to percolate into the soil, thereby decreasing groundwater recharge.

Improperly managed stormwater runoff can increase the incidence of flooding and the level of floods which occur, endangering property and human life.

Improperly managed stormwater runoff can interfere with the maintenance of optimum salinity in estuarine areas, thereby disrupting biological productivity.

Substantial economic losses result from these adverse impacts on community waters.

Many future problems can be avoided if land is developed in accordance with sound stormwater runoff management practices.

To encourage productive and enjoyable harmony between humanity and nature;

To protect, restore, and maintain the chemical, physical, and biological integrity of Hempstead Harbor and other community waters;

To prevent individuals, business organizations, and governments from causing harm to the community by activities which adversely affect water resources;

To encourage the construction of drainage systems which aesthetically and functionally approximate natural systems;

To encourage the protection of natural systems and the use of them in ways which do not impair their beneficial functioning;

To encourage the use of drainage systems which minimize the consumption of electrical energy or petroleum fuels to move water, remove pollutants, or maintain the systems;

To minimize the transport of pollutants to Hempstead Harbor and other community waters;

To maintain or restore groundwater levels;

To protect, maintain, or restore natural salinity levels in estuarine areas;

To minimize erosion and sedimentation;

To prevent damage to freshwater and tidal wetlands;

To prevent damage from flooding, while recognizing that natural fluctuations in water levels are beneficial;

To protect, restore, and maintain the habitat of fish and wildlife; and

To ensure the attainment of these objectives by requiring the approval and implementation of water management plans for all activities which may have an adverse impact upon community waters.

Unless exempted pursuant to Subsection B, a water management plan shall be submitted as follows:

Exemptions. The following development activities are exempt from the water management plan requirement:

It is the responsibility of an applicant to include in the water management plan sufficient information for the reviewing agency to evaluate the environmental characteristics of the affected areas, the potential and predicted impacts of the proposed activity on community waters, and the effectiveness and acceptability of those measures proposed by the applicant for reducing adverse impacts. The water management plan shall contain maps, charts, graphs, tables, photographs, narrative descriptions, and explanations and citations to supporting references, as appropriate to communicate the information required by this section.

The water management plan shall contain the name, address, and telephone number of the owner and the developer. In addition, the legal description of the property shall be provided, and its location with reference to such landmarks as major water bodies, adjoining roads, railroads, subdivisions, or towns shall be clearly identified by a map.

The existing environmental and hydrologic conditions of the site and of receiving waters and wetlands shall be described in detail, including the following:

Proposed alterations of the site shall be described in detail, including:

Predicted impacts of the proposed development on existing conditions shall be described in detail, including:

All components of the drainage system and any measures for the detention, retention, or infiltration of water for the protection of water quality shall be described in detail, including:

Any applicant for development as defined in this article, unless exempted, shall submit a water management plan to the Building Inspector.

A permit fee as provided in Chapter 125, Fees and Deposits, of the Village Code shall be collected at the time the water management plan is submitted.

When the application for development for which the water management plan has been submitted requires review by any other review board or agency other than the Building Inspector, the water management plan shall be considered and approved, with or without modifications, or rejected by that review agency within the time period required for that particular application. In all cases where the application is reviewed only by the Building Inspector, within 45 days after submission of the completed water management plan, the Building Inspector or his designee shall approve, with or without specified conditions or modifications, or reject the plan and shall notify the applicant accordingly. If the Building Inspector or his designee has not rendered a decision within 45 days after plan submission, he shall inform the applicant of the status of the review process and the anticipated completion date. If a water management plan is rejected or modified, the review agency or Building Inspector, as applicable, shall state his or its reasons. However, it is not the responsibility of the review agency or the Building Inspector to design an acceptable project.

The water management plan shall not be approved unless it clearly indicates the proposed development will meet the performance standards described in § 275-80 and the design standards described in § 275-81, except where off-site management is approved pursuant to § 275-82.

Inspections.

Ensure that after development, runoff from the site approximates the rate of flow, volume, and timing of runoff that would have occurred following the same rainfall under existing conditions and, to the extent practicable, predevelopment conditions, unless runoff is discharged into an off-site drainage facility as provided in § 275-82.

Maintain the natural hydrodynamic characteristics of the watershed.

Protect or restore the quality of ground- and surface waters.

Ensure that erosion during and after development is minimized.

Protect groundwater levels.

Protect the beneficial functioning of wetlands as areas for the natural storage of surface waters and the chemical reduction and assimilation of pollutants.

Prevent increased flooding and damage that results from improper location, construction, and design of structures in areas which are presently subject to an unacceptable danger of flooding.

Prevent or reverse saltwater intrusion.

Protect the natural fluctuating levels of salinity in estuarine areas.

Minimize injury to flora and fauna and adverse impacts to fish and wildlife habitat.

Channeling runoff directly into water bodies shall be prohibited. Instead, runoff shall be routed through swales and other systems designed to increase time of concentration, decrease velocity, increase infiltration, allow suspended solids to settle, and remove pollutants.

Natural watercourses shall not be dredged, cleared of vegetation, deepened, widened, straightened, stabilized, or otherwise altered. Water shall be retained or detained before it enters any natural watercourse in order to preserve the natural hydrodynamics of the watercourse and to prevent siltation or other pollution.

The area of land disturbed by development shall be as small as practicable. Those areas which are not to be disturbed shall be protected by an adequate barrier from construction activity. Whenever possible, natural vegetation shall be retained and protected.

No grading, cutting, or filling shall be commenced until erosion and sedimentation control devices have been installed between the disturbed area and water bodies, watercourses, and wetlands.

Land which has been cleared for development and upon which construction has not commenced shall be protected from erosion by appropriate techniques designed to revegetate the area.

Sediment shall be retained on the site of the development.

Wetlands and water bodies shall not be used as sediment traps during development.

Erosion and sedimentation facilities shall receive regular maintenance to ensure that they continue to function properly.

Artificial watercourses shall be designed considering soil type, so that the velocity of flow is low enough to prevent erosion.

Vegetated buffer strips shall be created or, where practicable, retained in their natural state along the banks of all watercourses, water bodies, or wetlands. The width of the buffer shall be sufficient to prevent erosion, trap the sediment in overland runoff, provide access to the water body, and allow for periodic flooding without damage to structures.

Intermittent watercourses, such as swales, should be vegetated.

Retention and detention ponds shall be used to retain and detain the increased and accelerated runoff which the development generates. Water shall be released from detention ponds into watercourses or wetlands at a rate and in a manner approximating the natural flow which would have occurred before development.

Although the use of wetlands for storing and purifying water is encouraged, care must be taken not to overload their capacity, thereby harming the wetlands and transitional vegetation. Wetlands should not be damaged by the construction of detention ponds.

The first one inch of runoff from impervious surfaces shall be retained on the site of the development.

Runoff from parking lots shall be treated to remove oil and sediment before it enters receiving waters.

Detention and retention areas shall be designed so that shorelines are sinuous rather than straight and so that the length of shoreline is maximized, thus offering more space for the growth of littoral vegetation.

The banks of detention and retention areas shall slope at a gentle grade into the water as a safeguard against drowning, personal injury, or other accidents, to encourage the growth of vegetation, and to allow the alternate flooding and exposure of areas along the shore as water levels periodically rise and fall.

The use of drainage facilities and vegetated buffer zones as open space, recreation, and conservation areas shall be encouraged.

The Building Inspector or his designee may allow stormwater runoff that is otherwise of unacceptable quality or which would be discharged in volumes or at rates in excess of those otherwise allowed by this article to be discharged into drainage facilities off the site of development if each of the following conditions is met:

A request to use off-site drainage facilities and all information related to the proposed off-site facilities shall be made a part of the developer's water management plan.

Drainage facilities shall be dedicated to the Village of Roslyn Harbor or County of Nassau as appropriate where they are determined to be appropriately a part of the Village- or county-maintained regional system or are unlikely to be adequately maintained by the developer or owner of the property. Acceptance of such dedications to the Village of Roslyn Harbor shall be solely at the discretion of the Board of Trustees.

Any easements required or provided by the applicant for drainage facilities shall be approved by the Village Attorney. The systems maintained by the owner shall have adequate easements to permit the Village of Roslyn Harbor to inspect and, if necessary, to take corrective action should the owner fail to properly maintain the system. Before taking corrective action, the Village shall give the owner written notice of the nature of the existing defects. If the owner fails within 30 days from the date of notice to commence corrective action or to appeal the matter, the Village may take necessary corrective action, the cost of which shall become a lien on the real property until paid.

Nuisance. Any development activity that is commenced without prior approval of a water management plan or is conducted contrary to an approved water management plan as required by this article shall be deemed a public nuisance and may be restrained by injunction or otherwise abated in a manner provided by law.

Violations of provisions of this article shall be subject to the provisions of § 275-54 of this chapter.

Any violator may be required to restore land to its undisturbed condition. In the event that restoration is not undertaken within a reasonable time after notice, the Village of Roslyn Harbor may take necessary corrective action, the cost of which shall become a lien upon the property until paid.

Notice of violation.