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Benefits of Continued Virginia Coastal Zone Wetland Buffer Preservation and Implementation. Bryan Johnson Wetland Soils 570. Virginia’s Coastal Zone. Covers approx. one-quarter of the state (5,727,977 acres)
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Benefits of Continued Virginia Coastal Zone Wetland Buffer Preservation and Implementation Bryan Johnson Wetland Soils 570
Virginia’s Coastal Zone • Covers approx. one-quarter of the state (5,727,977 acres) • Extends from the flat sandy soils of the Eastern Shore and southeastern Virginia, to the gently rolling forests and farmlands of the Peninsula, Middle Peninsula, and Northern Neck • Includes the highly developed areas that extend from the metropolitan localities of Fairfax, Alexandria, and Arlington, south along the interstate 95 corridor which passes through the cities of Fredricksburg, Richmond, and Petersburg • It also extends east and south along the Interstate 64 corridor to the port of Hampton Roads and ocean coast at Virginia Beach VADEQ, 2001
Coastal Zone Population Increase • Population in Virginia’s coastal localities increased by more than 500,000 people between 1990 and 2000 • Additional people in the coastal zone has resulted in an increase in the conversion of forest and agricultural lands to developed lands • Virginia ranks 11th in the nation for the rate of land conversion (approx. 68,700 acres per year changed from farming and forest to residential/commercial uses) • Within Virginia, the coastal zone is the area undergoing the most rapid changes • The National Resource Inventory estimated that developed lands in the Virginia Coastal zone grew by 54 percent between 1982 and 1997 (compared to a 43% statewide rate for the same interval) VADEQ, 2001
Reasons For Growth • Virginia’s Coastal Zone Provides an Excellent Habitat for Humanity • Natural Assets Of Virginia’s Coastal Zone – Include fertile land, moderate climate, productive estuaries and ocean, and it is located in the middle of one of the world’s greatest civilized seacoasts • Mix of Resource Based Industries – Forestry products, agriculture, mining and commercial fisheries • Natural Resources/Recreational Activities – Hunting, fishing, boating, and bird watching
Coastal Zone Land Usage • Even with the relatively high rates of land conversion, more than half of the coastal zone land area remains forested • Approximately one quarter of the land area is used for farming • Of the remaining non-forested land, about 9 percent of the area is developed and wetlands occupy over 10% of the remaining area VADEQ, 2001
Coastal Zone Wetlands • The coastal zone contains all 310,813 acres of Virginia’s tidal wetlands and 909,097 acres (approximately 80%) of the state’s nontidal wetlands • It has been estimated that over half of Virginia’s wetlands have been lost since colonial times - Most historic nontidal losses are attributed to agriculture while most historic tidal wetlands losses have been caused by commercial and residential development along the shore line. Currently, nontidal wetland impacts are generally a result of commercial and residential development while tidal wetland impacts are often associated with construction of shoreline erosion protection structures. As with tidal wetlands, small incremental impacts on subaqueous lands can cumulatively alter the aquatic environment. Immediate impacts, which may be long term result from large dredging and shoreline nourishment projects. • Recent wetland management programs have • slowed the rate of losses considerably, however, • current growth and development trends • continue to impact wetlands • Between 1996 and 2000, approximately 145 • acres of tidal wetlands and 1138 acres of • nontidal wetlands were impacted in the coastal • zone VADEQ, 2001
Why are our wetlands important? • Hydrologic Value - Wetlands slow and retain surface water, providing water storage and shoreline stabilization • Water Quality - Remove pollutants from surface runoff and small streams by retaining sediments and toxic pollutants attached to those sediments such as PCPs, phosphorus, heavy metals and pesticides. Wetland plants also transform N and P into unavail. forms, reducing algal blooms and fish kills caused by these nutrients. • Habitat Values - Wetlands provide wildlife habitat for a wide range of terrestrial and semi-aquatic animals and numerous plant species. The aquatic and terrestrial habitats within a wetland provides a variety of food sources and cover for nest sites and subsequent young. • Direct Use Values - Because wetlands provide such a diversity of habitat for so many animals, they are of great use to humans through recreation, education and timber production. In recreation and education, wetlands provide areas for both consumptive and non-consumptive use. Consumptive use involves hunting and fishing, while non-consumptive uses include canoeing, bird watching, and studying animals and plants. Wetlands also have economic value of producing sawtimber and pulpwood. Many wetlands are dominated by trees and are actively managed for timber production
How can we protect our wetlands? • Answer: WETLAND BUFFERS • All wetland types are important resources, which is why even “marginal” wetlands are important to preserve and protect with some type of “Buffer” • What is a wetland buffer? • Area of vegetation which usually begins from the boundary of wetland dependent vegetation and extends outward, ending at the interface with another land use • Vary in size and nature depending upon the specific purpose for which it was created • Transition zones between the terrestrial and aquatic ecosystem, linking land and water on a given site or property, and linking landscapes together in a watershed
Wetland Buffer Vegetation • Wetland buffers containing diverse, multilayered, undisturbed vegetation result in maximum wetland quality and wildlife protection benefits • Each vegetative type has its own beneficial character - Grass has a high stem density effective in filtering - Trees stabilize soil and dissipate rainfall energy - Shrubs are effective in filtering, stabilizing soil and dissipating rainfall energy Example of a Wetland Buffer Castelle et al., 1994
Hydrologic Importance of Wetland Buffers • Provide an area for surface water and groundwater interaction • -As water flows across a buffer, it infiltrates through the vegetation, reducing the volume of runoff reaching the wetland. Secondly, as excess water is stored in the wetland, water levels rise and expand over the buffer area, thus presenting more surface area and another opportunity for water to soak into the ground • Reduce surface water runoff from surrounding land into the wetland • Potential storage/treatment system prior to direct discharge into wetland for drainage systems that are storm-sewered, drain-tiled or channelized
Impact of Wetland Buffers on Water Quality • Provide pretreatment of runoff to ensure that natural wetland functions are not overwhelmed thereby sustaining wetland cleansing capabilities • Play a role in pre-treatment simply by their inherent nature as a place for water to filter, soak in, contact soil and be taken up by vegetation • Effective at providing some degree of pre-treatment for several sources of pollution such as: • 1. Solids • 2. Phosphorus • 3. Nitrogen • 4. Biological pollutants • 5. Heavy Metals
Impact of Wetland Buffers on Solid Removal • Wetland Buffer Vegetation reduces energy of flow, thus slowing water down, spreading flow out and allowing gravity to settle particles too heavy to move at a reduce energy level • Figure 1 indicates that TSS (Total Suspended Solid) reduction of 70% and more can occur with certainty when buffer widths reach 50’ • Figure 1 shows that the lower limit of 70% occurs for every instance when 100’ of buffer was in place • The relationship of buffer width to water quality improvement is not linear, therefore, large increases in buffer size do not necessarily yield similar water quality benefits Emmons, 2001
Impact of Wetland Buffers on Phosphorus Removal • Particulate filtering of organic material (ex., grass, leaves, woody debris) is the principal P reduction process in wetland buffers • Over time, organic material breaks down, sorption bonds break and soluble phosphorus becomes mobile, at which point it can soak into the soil, be taken up by vegetation or flow away • Figure 2 shows that a 50’ buffer width marks the transition between relatively low Phosphorus removal and higher removals (>65%) • Similar to TSS removal, relationship of buffer width to water quality improvement is not linear, therefore, large increases in buffer width may not yield similar water quality benefits Emmons, 2001
Impact of Wetland Buffers on Nitrogen Removal • Wetland buffers contribute substantially to the preservation of groundwater quality by removal of NO-3 through denitrification and plant uptake • Figure 3 illustrates the removal of subsurface nitrate as a function of buffer width • Nitrate removal in buffers occurs mostly in the sub-soil, where anaerobic bacteria transform, or denitrify, nitrate to nitrogen gas • Surface nitrate removal (Figure 4) shows a similar pattern to all of the other contaminant removal versus buffer width relationships, however, overall removal seems to be less in the lower buffer width range • Nitrate is a soluble transition produce best reduced under anaerobic conditions in the soil • Surface reductions come mostly from infiltration, which becomes more of a factor for wider buffers Emmons, 2001
Habitat Benefit Due to Wetland Buffers • Benefits of wetland buffers for both aquatic and terrestrial wildlife include corridor extension/connection, breeding and nesting cover, food sources, roosting sites, predator protection, and shelter from cold and hot temperatures • Water Cool Down Effect of Wetland Buffers - Buffer areas near standing water shade the water and keep temperatures down during the summer and, also help cool warm water runoff as it flows through wetland buffer vegetation. The cooling allows water to hold more oxygen at lower temperatures resulting in a viable aquatic environment. • Wetland buffer areas lesson the importance of knowing the exact wetland boundary, therefore, allowing for some transition to occur, however, this does not minimize the importance of establishing a • line for purposes of defining buffer width
Quality of Life Benefits Due to Wetlands Buffers • Wetland Buffers not only protect our wetlands, but they act as extensions and add to all of the quality of life benefits associated with wetlands • Aesthetic and Open space values of Wetlands are Immeasurable • Recreation Benefits: • Provide walking/running/hiking trails • Site Seeing/Photographing • Hunting/Fishing • Education Benefits: • Study how nature works • Identify plant/animal species • Learn about water resources
Suggested Wetland Buffer Zone Minimum Width Recommendations Emmons, 2001and Castelle et al., 1994
Current Virginia Laws & Regulations Relevant to Protecting Our Wetlands • Wetlands have been protected in Virginia since the passage of the Wetlands Act in 1972. Since then a variety of legislation has emerged to prevent the destruction of these important habitats such as the following: • Wetlands Act, Title 28.2 Chapter 13 • The Tidal wetlands Act is Virginia legislation aimed at protecting vegetated and nonvegetated tidal wetlands in Virginia. The goal of this law is to, “preserve and prevent the despoliation and destruction of wetlands while accommodating necessary economic development in a manner consistent with wetlands preservation” (VA Code 28.2-1302). The Wetlands Act vests wetland regulatory authority in the hands of the local government. • This act created a Wetlands Zoning Ordinance that any county, city, or town in Virginia may adopt to regulate the use/development of local wetlands. Adoption requires localities to create a wetlands board consisting of five or seven residents of the jurisdiction. Local board jurisdiction extends from mean low water to mean high water where no emergent vegetation exists, and to 1.5 times the mean tide range where marsh is present. • The Virginia Marine Resources Commission is required by the Wetlands Act to, “Promulgate and periodically update guidelines which scientifically evaluate vegetated and non vegetated wetlands by type and describe the consequences of use of these wetlands types” (Section 28.2-1301). To accomplish this task, the Virginia Institute of Marine Science is charged with advising and assisting the Commission. • VMRC has jurisdiction over the permitting of projects within state-owned subaqueous lands. They also review proposed projects impacting wetlands, sand dunes and beaches in localities that have note adopted the Wetland Zoning Ordinance Trono, 2003
Virginia Wetland Protection Laws & Regulations (continued) • Chesapeake Bay Preservation Act, Title 10.1 Chapter 21 • The Chesapeake Bay Preservation Act passed in 1988 with its purpose being to improve the water quality of the Chesapeake Bay and its tributaries through measures to reduce adverse impacts of land use and development • Local governments, under the Bay Act, are required to designate Chesapeake Bay Preservation Areas (CBPAs), and incorporate protection of water quality into their comprehensive plans and ordinances. Many localities have adopted a model ordinance created by the Chesapeake Bay Local Assistance Department • The bay Act and regulations require a 100 feet wide vegetate buffer adjacent to and landward of all tidal shores, tidal wetlands, non-tidal wetlands connected by surface flow and contiguous to tidal wetlands or along water bodies with perennial flow. The Bay Act also stipulates that all land disturbances over 2,500 square feet that occur in CBPAs are required to comply with all local erosion and sediment control regulations • VMRC has jurisdiction over the permitting of projects within state-owned subaqueous lands. They also review proposed projects impacting wetlands, sand dunes and beaches in localities that have note adopted the Wetland Zoning Ordinance • Erosion & Sediment Control Law, Title 10.1 Chapter 5 Article 4 • The ESC Program’s purpose is to control soil erosion, sedimentation, and nonagricultural runoff from regulated “land-disturbing activities” to prevent degradation of property and natural resources. DCR, the leading state agency for developing and implementing statewide nonpoint source pollution control programs and services, administers erosion and sediment control laws. Localities require a separate E & S permit. Originally E & S law reviewed projects over 10,000 square feet. With passage of the Chesapeake Bay Preservation Act, this threshold was amended to include projects that disturb 2500 square feet or more land in Chesapeake Bay Preservation Areas (CBPAs) Trono, 2003
Virginia Wetland Protection Laws & Regulations (continued) • Non-tidal Wetlands Program-DEQ Virginia Water Protection Program • The Virginia Water Protection Program at DEQ is responsible for the administration of the Section 401 water quality programs delegated to the Commonwealth under the Clean water Act. The program also regulates impacts to state waters including wetlands as required under the State Water Control Law. The goal of VWPP is to ensure, “no net loss of wetland acreage and function, protect beneficial uses of state waters, prevent degradation of valuable water resources, and to work toward the restoration of waters whose quality has been degraded” (VWPP Guidelines, 2003). • United States Army Corps of Engineers • Based on Section 10 of the Rivers and Harbors Act of 1899 and Section 404 of the Clean Water Act, the Corps is responsible for administering a permit program for construction, dredging and filling activities in tidal and nontidal wetlands. The corps wetland definition is based solely on soil type, hydrology, and present vegetation. This differs form the commonwealth of Virginia definition which is based on vegetation, elevation, and connectivity. Trono, 2003
Facts of Wetland Buffer Management • Protection of Wetlands by Buffers is an important part of all comprehensive surface water management plans • Buffers surrounding all wetlands are necessary not only for the protection of wetlands and the benefits they provide, but also for the functions/values that buffers serve as vegetative areas such as: • Water Quality Protection – erosion/sediment control, • nutrient, biological, and toxin removal • Hydrologic Event Modification/Groundwater • Interaction • 3. Aquatic/wildlife habitat protection • 4. Aesthetics/open space - Minimization of • Human Impact • 5. Recreation/Environmental Education • Buffers, used as non-structural BMP’s, can possibly negate the need for more expensive structural approaches • Enhancement of wetland buffers to assure their continued existence and functionality is warranted as part of good overall watershed management that supports low impact development and promotion of infiltration techniques. • Maintenance of buffer areas is essential to proper long-term operation with emphasis placed towards keeping runoff over the buffer in sheet flow, removing accumulations of pollutants, keeping vegetation healthy and keeping soils pervious.
Looking to the Future • Virginia is committed to preserving and protecting wetlands • State parks, natural area preserves, wildlife management • areas and unclaimed tidal lands currently offer protection • to over 36,000 acres of wetlands through conservation • programs that permanently restrict development by way • of perpetual easements or fee ownership, held by federal, • state or local government or non-profit organizations • Buffers along streams, rivers, and wetlands of the Commonwealth provide water quality and habitat benefits for both aquatic and terrestrial biota. • Because of the importance of buffers, Virginia has placed upwards of 72 linear miles of buffers along our waters as part of a government enforced restoration project and hopes to restore 610 miles by 2010 VADEQ, 2001
Looking to the Future • The Virginia Coastal Zone is under stress primarily because it is an excellent habitat for humanity, as it offers a wide diversity of opportunities to pursue business and recreation. • The attractiveness of the region has brought with it the challenges of supporting an ever expanding human population. • Expanding and shifting human uses of the system have made it very difficult to sustain healthy fisheries, high water quality, and balanced land uses. • Today, Virginia is confronted with problems of accommodating expanding development, while preserving forests, farms, open spaces and wetlands. • The search for optimal wetland protection will be never-ending in the face of growing populations, evolving technologies, and changing climate • The future of wetland protection in Virginia is bright, as the number of interested and informed policy-makers, managers, non-governmental interests, and private citizens continues to grow
Looking to the Future • In determining wetland protection needs of the future, we will face a difficult and likely never ending challenge due to population growth, improvements in technology, and climate change. The following concerns must be addressed as we strive to protect our wetlands: • Improve and expand existing regulatory and non-regulatory county, state, and federal wetland protection programs • Collaborate and learn from other jurisdictions outside the coastal zone • Increase the involvement/education of local stakeholders • Continually educate all citizens on the value of wetlands • Improve the Implementation of wetland protection program regulations set by county, state, and local governments • Maintain focus on maintaining and improving our environment
References Burt, T. P., L. S. Matchett, K. W. T. Goulding, C. P. Webster, and N. E. Haycock, 1999. Denitrification in riparian buffer zones: the role of flood plain hydrology. Hydrological Processes 13:1451-1463. Castelle, A. Y. and A. W. Johnson, 2000. Riparian Vegetation Effectiveness. National Council for Air and Steam Improvement (NCASI), Triangle Park, N. C., Technical Bulletin No. 799, 26 p., February 2000. Castelle, A. J., A. W. Johnson, and C. Conolly, 1994. Wetland and Stream Buffer Size Requirements – A Review. Journal of Environmental Quality, 23:878-882. Emmons, William, 2001. Benefits of Wetland Buffers: A Study of Function, Values, and Size. Technical Bulletin #5504. December 2000. Trono, Krista L, 2003. An Analysis of the Current Shoreline Management Framework in Virginia: Focus on the Need for Improved Agency Coordination. Virginia DEQ Report funded by the Virginia Coastal Resources Management Program. Virginia Department of Environmental Quality, 2001. State of Virginia’s Coast. VIMS report funded by a grant from the Virginia Coastal Resources Management Program.