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Virginia CZM Program: 2014 Coastal Grant Project Description and Final Summary

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Northern Virginia Regional Commission

Project Title:

Land and Water Quality Protection Northern Virginia Phase I: Municipal Policies for Managing Stormwater with Green Infrastructure 

Project Description as Proposed:

For more than thirty years, NVRC has actively been involved with its member local governments on water quantity and quality issues.  Stormwater runoff has become the focus of many state and federal regulatory efforts to address water quality problems as failure to meet water quality standards continues to be a widespread problem.  Stormwater runoff from urban areas has been determined to be a major cause of water quality impairment, including the inability of surface waters to meet their state-designated uses to support recreation and aquatic life.

As such, the National Pollution Discharge Elimination System (NPDES) requirements were expanded to include the municipal separate storm sewer systems (MS4) owned and operated by counties, cities, and towns in urbanized areas.  To provide further water quality protection, these regulations are now being coupled with emerging regulations for low impact development, enhanced storm water management, non-point source pollution management programs, and most importantly for local governments, Total Maximum Daily Loads (TMDL’s) by both state and federal agencies.  These regulations require new land use approaches and development policies that will help localities reduce the impacts of land development on water quality. Even though this region has been proactive in the area of stormwater management, the newly developed stormwater management regulations and mandatory requirements will soon force a completely new approach as well as the development of new local programs and policies. The constantly shifting developments, time demands and cross cutting program relationships are now such that local government departments in many instances can no longer utilize a single staffer to be the local government expert.

To provide technical support and analysis on matters such as storm water management regulations, MS4 permit developments and local and regional TMDL’s, NVRC has been convening a Northern Virginia MS4 Workgroup comprised of local government staff.  The Workgroup has developed a Regional Strategy for Managing Urban Storm Water Quality in Northern VA.  One of the goals identified in the Strategy is to, “identify regionally appropriate and cost effective Best Management Practices.”

EPA encourages the use of green infrastructure to help manage stormwater runoff.  The Center for Watershed Protection defines it as “Green Infrastructure refers to natural systems that capture, cleanse and reduce stormwater  runoff using plants, soils and microbes. On the regional scale, green infrastructure consists of  the interconnected network of open spaces and natural areas (such as forested areas,  floodplains and wetlands) that improve water quality while providing recreational opportunities, wildlife habitat, air quality and urban heat island benefits, and other community benefits. At the site scale, green infrastructure consists of site-specific management practices (such as interconnected natural areas) that are designed to maintain natural hydrologic functions by absorbing and infiltrating precipitation where it falls.”

Many localities are realizing that green infrastructure can be a solution to the land use and water quality challenges facing municipalities including stormwater management and flood control however, the exact extent is not always known.  In order to identify “regionally appropriate and cost effective Best Management Practices” for Northern Virginia, a methodology for modeling impacts of various development scenarios on water quality is an essential tool. 

The funding requested through this proposal will allow NVRC to do three things:
1) review the current and planned state and federal regulatory requirements pertaining to local water quality as well as the local ordinances and policies that protect water quality;
2) work with experts at George Mason University to evaluate the value of green infrastructure at a regional scale as well as a site scale as a “regionally appropriate and cost effective Best Management Practice” using the tools and recommendations for modeling that were developed by the Hampton Roads PDC under the 309 Water Quality Strategy; and
3) provide recommendations for localities to adopt policies and programs that allow, encourage, and require green infrastructure to be integrated into the regional landscape where appropriate. 

A separately funded NVRC effort that is planned for Spring of 2015 and Spring of 2016 is a series of three facilitated workshops between the regions of Stuttgart, Guelph, and Northern Virginia that will coordinate the analysis and interpretation of how cross-national transfer of green infrastructure innovations can be applied under the technical, legal, and policy conditions between all three countries.  The outcome will be the international transfer of specific technical green infrastructure innovations for stormwater management, air pollution mitigation, and urban heat island mitigation.  The products from this separate effort will be closely related and can be incorporated into the final deliverables of this 309 project.

Regulatory Setting
The Commonwealth will utilize MS4 permits to ensure BMP implementation on existing developed lands achieves nutrient and sediment reductions equivalent to Level 2 (L2) scoping run reductions by 2025. Level 2 implementation equates to an average reduction of 9 percent of nitrogen loads, 16 percent of phosphorus loads, and 20 percent of sediment loads from impervious regulated acres and 6 percent of nitrogen loads, 7.25 percent of phosphorus loads and 8.75 percent sediment loads beyond 2009 progress loads for pervious regulated acreage. These reductions are beyond urban nutrient management reductions for pervious regulated acreage. MS4 operators will be able to adjust the levels of reduction between pervious and impervious land uses within their service area, provided the total pollutant load reduction is met. For example, an MS4 could implement a five percent nitrogen load reduction on impervious land uses by implementing a reduction strategy sufficiently greater than six percent nitrogen load reduction on pervious land uses provided the total loads from both land uses are met.

MS4 Permittees are required (by Phase II WIP) to complete local TMDL Action Plans (for local TMDL’s established by July 2008) and Chesapeake Bay TMDL Action Plans.  Action Plans must be submitted with the Annual Report for the reporting period of July 1, 2014 through June 30, 2015 to the Department by October 1, 2015. The Action Plans will include a review of the baseline program and include an outline of the means and methods that will be utilized to meet the L2 level necessary for the permit. The MS4 operator will also review its authorities, adopt and modify the necessary ordinances, and enhance its resources in order to implement the necessary reductions (e.g., develop design protocols, operation and maintenance programs, site plan review criteria, inspection standards, and tracking systems). As a part of reapplication for the second cycle of permit coverage, the MS4 operator will provide a schedule of implementation of the means and methods to implement sufficient reductions to reach 35 percent of the L2 reductions. As a part of reapplication for the third cycle of permit coverage, the MS4 operator will provide a schedule of implementation of the means and methods to implement sufficient reductions to reach the remaining L2 reductions by the end of the third permit cycle.

DEQ and DCR intend for nonpoint source reductions recommended in TMDLs to be implemented through Best Management Practices (BMPs) and expect that implementation will occur in stages.  DCR will work with MS4s on an individual basis to develop plans to achieve L2 reductions in each permit cycle including strategies for increasing BMP implementation levels.

Problems and Opportunities
Afforestation should meet the criteria for inclusion as a BMP but it is not currently approved as such in the VA BMP Clearinghouse. New forests provide additional nutrient load reduction services that were not present in a watershed prior to project implementation. However, existing forestland is not currently credited for water quality protection in the WIP. Even as new forests are created through BMPs implemented pursuant to the WIP, Virginia continues to experience a net loss of approximately 16,000 acres of forestland per year, based on a rolling ten year average, according to Forest Inventory Analysis. This forestland loss impacts nutrient and sediment loads and overwhelms the ability of afforestation to keep pace with nutrient and sediment load reduction targets on a landscape scale. Developing strategies that influence the rate of forestland conversion is of great importance in the context of protecting water quality over the long term.

With the obligation to meet nutrient and sediment loads contained in the Chesapeake Bay
TMDL, Virginia has an opportunity to incorporate into the Phase II WIP strategies to slow or reverse the loss of forestland and the associated water quality benefits. Such strategies would recognize the direct value that forests provide for water quality, with such ancillary benefits as water infiltration and storage, biodiversity, carbon sequestration, air quality, pollination, and others.

There exists the opportunity to include strategies in urban and suburban areas that impact tree canopy and urban forest cover. Several localities in Virginia have strong tree preservation ordinances that value the environmental benefits associated with tree cover. Gaining recognition in the Chesapeake Bay Model for an urban locality’s effort to preserve, enhance, and maintain the urban tree canopy is critically important. Strategies in the action plan to manage conservation of urban tree canopy and retention of urban forest cover could include identification of priority areas for retention, setting percent forest cover retained guidelines for development, and replanting cleared areas. Priority areas for retention would include flood plains, intermittent and perennial streams, steep slopes, and critical habitats. An urban and community forest retention strategy will reduce the rate of tree canopy and urban forestland loss as population growth increases.

Why is NVRC involved?
State Strategy for Local Engagement
The state has chosen to engage the localities on the Phase II WIP process through the sixteen Planning District Commissions (PDCs) in the Chesapeake Bay watershed. The PDCs were established by § 15.2 of the Code of Virginia “to encourage and facilitate local government cooperation and state-local cooperation in addressing, on a regional basis, problems of greater than local significance. The cooperation resulting from this chapter is intended to facilitate the recognition and analysis of regional opportunities and take account of regional influences in planning and implementing public policies and services.' Further, the PDCs are comprised of the individual localities within the geographic area covered by the PDC and have a long tradition in Virginia of promoting and advancing solutions for managing complex and regional problems including water resource planning. Using this vehicle for engagement, Virginia has been able to communicate to the local governments, PDCs, SWCDs, and local representatives of federal facilities their contribution to and responsibility for managing the Chesapeake Bay TMDL.

Phase II WIP Strategies Regarding Urban Tree Canopy

Activity  Statewide 2025 Goal 
Impervious Urban Surface Reduction (Acres)  26,138 
Forest Buffer Urban (Acres)  4,115
Forest Conservation (Acres)  14,128 
Urban Tree Planting (Acres)  799 

Urban Tree Planting Phase II WIP Strategies
• Explore opportunities for tree planting in underused urban areas
• Review existing landscapes or tree canopy ordinances or develop new ones to promote additional tree cover. (Staff resources needed for ordinance work and funding for trees)
• Evaluate increasing tree planting requirements for newly developed and redeveloped single family homes. Requiring additional trees beyond any mitigation requirements to be planted for each unit above current standards could provide increased canopy cover and decreased pollutant generation for the locality.
• Participate in the Journey Through Hallowed Ground Living Legacy project where trees memorializing soldiers killed during the Civil War will be planted to increase tree canopy.
• Implement urban forest buffers in accordance with funding availability & demonstrate effectiveness to the public.
• Limited to availability of funds of planting sites & cost of easements on/acquisition of private land.
• Evaluate the potential to increase the number of new trees planted with ongoing construction projects and with new/redevelopment single family homes.
• Consider implementing Urban Forest Management Plans using capital improvement project funding
• Consider developing a cost-share program to encourage private properties to plant trees to convert land into forests or to provide streamside riparian buffers and establish conservation easements.
• Grant or other funding for program development, training and maintenance.
• Explore options to enhance landscaping requirements to allow for more tree plantings in commercial developments.
• Explore ideas and options for establishing 'green partners' from both public and private sectors to encourage, promote and implement urban forestation projects.
• Consider purchasing land and converting it to forest rather than constructing certain BMPs if construction costs for a specific BMP are deemed unacceptable
• Consider establishing locality buffer workshops. The program could be created to reach a large audience and include aggressive improvements byencouraging tree planting in the buffers.

Land Use Change BMP’s as a vehicle for Urban Forestry
Permittees may receive credit towards their required reductions for land use change conversions based on the number of acres converted. Conversion efficiencies for land use change are dependent on basin and are listed in Table V.F.1. Permittees may receive credit for converting:
1. Impervious to Forest – Permittees may receive credit for converting any Impervious Surface to Forest. To receive credit for the “Forest” land use, permittees should meet the tree density per acre described in the Virginia Department of Forestry’s Land Use Tax Assessment Standards, which can be found on the Virginia Department of Forestry’s website:
2. Impervious to Grass – Permittees may receive credit for converting any Impervious Surface to Grass. To qualify for this credit the “Grass” must be unmanaged (i.e. no nutrient application).
3. Impervious to Pervious – Permittees may receive credit for converting any Impervious Surface to a Pervious Surface other than Forest and/or Grass. Pervious surfaces might include: lawns, unimpacted gravel, etc. If a permittee is unsure if a surface is considered “pervious,” the Department should be contacted for further guidance.
4. Pervious to Forest – Permittees may receive credit for converting any Pervious Surface, including unmanaged Grass, to Forest.
5. Pervious to Grass – Permittees may receive credit for converting any Pervious Surface, other than Forest, to unmanaged Grass.

Basin  Land Use From  Conversion  Edge of Stream
Edge of Stream
Edge of Stream
Potomac Impervious  Forest  13.91  1.80  1252.01 
Potomac  Impervious  Grass  12.56  1.34  623.28 
Potomac Impervious  Pervious  6.75  1.42  1119.05 
Potomac  Pervious  Forest  7.16  0.38  132.96 
Potomac  Pervious  Grass  5.81  0.00  0.00 

Riparian Forest Buffers can be credited as both a land use change and efficiency BMP.  The efficiency is applied at up to a 2-to-1 ratio for upland acres that drain to the buffer as sheetflow (i.e. if a one acre buffer is installed, but only 1.5 upland acres drains to the buffer as sheetflow, the permittee may only receive the efficiency credit for 1.5 acres). The following established efficiencies for TP, TN, and TSS should be used:

Efficiencies for Forest Buffers Applied to Two Upland Acres per Acre of Buffer

Practice  TN  TP  TSS 
Forest Buffer  25%  50%  50% 

Federal Funding:


Project Contact:

Corey Miles, 703.642.4625;

Project Status:

11/1/14 - 9/30/15; Project Open

Final Product Received:

Land and Water Quality Protection in Northern Virginia: Phase I (PDF) 

Project Summary Provided by Grantee:

A major challenge facing the Northern Virginia region is the shift in land cover from pervious to impervious which has increased the volume of stormwater runoff.  Stormwater runoff from urban areas has been determined to be a major cause of water quality impairment, including the inability of surface waters to meet their state-designated uses to support recreation and aquatic life.  In addition to the degradation of streams and loss of property, the erosive forces of excessive runoff can put municipal infrastructure, such as sewer pipes, at risk.

The Chesapeake Bay Program recognizes that urban impervious land cover is a major contributor to the total load of Total Nitrogen (TN), Total Phosphorous (TP), and Total Suspended Solids (TSS).  There exists the opportunity in local stormwater planning to incorporate strategies in urban and suburban areas of Virginia that could include urban forest cover. This project identified if maintaining and/or increasing urban tree canopy was be a cost effective and meaningful tool to assist local governments with meeting water quality milestones in not only a complex regulatory environment, but also in the complex land use and development environment of Northern Virginia.

To answer the above question, four things were studied; 1) the current policies regarding urban tree canopy in northern VA, 2) the population projections in Tranpsortation Area Zones through 2040, 3) effects of those projections on land cover, and 4) the potential future effects on water quality from a. doing nothing and b. maximizing tree cover. 

Many localities in Northern Virginia have adopted one or more ordinances governing tree management and care on development sites. Gaining credit in the Chesapeake Bay Model and VA BMP Clearinghouse for these locality’s efforts to preserve, enhance, and maintain the existing urban tree canopy is important since preservation and maintenance of existing canopy is less expensive than retrofits or other engineered solutions per-pound of Nitrogen reduced. The ordinances governing tree canopy vary significantly across the boundaries of Northern Virginia. Some have interpreted the Code of Virginia § 15.2-961 in different ways by either adhering to the minimum standards set forth or through much more prescriptive ways.

Build-out analysis derived from population projections indicated that impervious cover will continue to grow and tree canopy will decrease in the region, and that it varies by watershed.  Streams in high growth watersheds will develop flashy characteristics that will increase erosion.  Results indicate that retaining and increasing urban tree canopy provides significant runoff reduction benefits.  Loads of TN and TP were reduced slightly but not at the same level as other types of retrofits such as bioretention.

The final products contain a number of enforceable policy recommendations including increasing minimum ten-year tree canopy percentages for developers who cut trees by five percent in all zones. 

Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or email:

A more detailed Scope of Work for this project is available. Please direct your request for a copy to

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Virginia Department of
Environmental Quality
P.O. Box 1105
Richmond, VA 23218
(804) 698-4000

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