Riparian Restoration

By Elizabeth M. Norris*

Introduction

Riparian ecosystems are located on river flood- portant to the animals of the riparian ecosys- plains, and are part of the highly integrated system: (1) predominance of woody plant commu- tem that includes the stream channel. Overlap- nities, (2) presence of surface water and abun- ping terms commonly used are riparian forests, dant soil moisture, (3) diversity of interspersion riverine wetlands and riparian corridors. Ri- of habitat features, and (4) corridors for dis- parian ecosystems are connected to aquatic eco- persal and migration. In heavily farmed or ur- systems both by direct fluxes and, below-ground, ban regions, riparian areas are often the only through the hyporheic zone (Lowrance et al. wooded segments remaining. Trees and shrubs 1997). found in these buffers provide protection, roost- ing areas, and favorable microclimates for many In much of the world, riparian areas are domi- species. The riparian vegetation also shades the nated by forests. However, not all riparian zones stream, stabilizes the streambank with tree or river marginal areas are forested in their natu- roots, and produces leaf litter, all of which sup- ral condition. Even predominately forested ar- port a greater variety of aquatic life in the stream. eas may have inclusions of marshes dominated by emergent herbs, open water dominated by sub- Riparian ecosystems have many functional char- mersed plants or plankton, and unvegetated acteristics that result from the unique physical sand bars lacking trees (Brinson and Verhoeven environment. It is recognized that they are highly 1999). Only a small portion of most landscapes productive because of the convergence of energy are occupied by riparian forests and while the and materials that pass through riparian wet- contribution of these ecosystems to sustain lands in great amounts. Riparian wetlands are aquatic organisms is profound, they also have a also generally more productive than adjacent central role in sustaining a variety of terrestrial upland ecosystems because of their unique hy- organisms. drologic conditions (Mitsch and Gosselink 1993). A riparian forest buffer is an area of trees, usu- ally accompanied by shrubs and other vegeta- These shoreline landscapes concern land man- tion, that is adjacent to a body of water. Buffers agers and social scientists because they are af- are managed to maintain the integrity of stream fected by water resource developments and as- channels and shorelines. They also reduce the sociated land use (Malanson 1993). Riparian impact of upland sources of pollution by trap- areas have many values (Figure 1). Because of ping, filtering and converting sediments, nutri- their location, riparian areas were often selected ents, and other chemicals. Buffers help to ab- for early settlements. The existing waterways sorb periodic flood pulses, and to supply food, were used for transporting people and goods cover, and thermal protection to fish and other quickly and efficiently, and the water offered a wildlife. Brinson et al. (1981) described four eco- simple system for primitive waste disposal. logical attributes of forested buffers that are im- Because of these benefits, riparian areas have historically been a popular choice for urban de- *Libby Norris works for the Chesapeake Bay velopment. Expanding population centers di- Foundation as the Virginia Restoration Scientist. rectly impact stream-side lands that once sup-

1 Existing Riparian Systems Economic Values Social Values Biological Values › reduce downstream flooding › recycle nutrients, tighten spiral › special habitat for some › high yield of timber and storage endangered or threatened › recharge aquifers › store heavy metals and toxins species › surface water supply › intermediate storage for sediments › refugia for upland species › support secondary productivity › natural heritage › corridors for species (e.g. fisheries) › natural laboratories for teaching movement and research › recreation › aesthetics

Former Riparian Systems ported riparian ecosystems and continually in- Economic Values crease their demands on a decidedly finite water › transport corridors supply (Patten 1998). The popularity of ripar- › water supply and electricity ian recreation sites also leaves them vulnerable › construction materials and waste disposal to over-use and misuse (Johnson and Carothers › agriculture and livestock 1982). Motorized recreation has major impacts › settlement on many riparian resources.

Losses of riparian habitat are difficult to esti- Figure 1. The values of riparian ecosystems mate but are considered to be great (Malanson (Malanson 1993) 1993). Early logging operations used major waterways to transport large logs to downstream Wetlands Program mills, greatly impacting the shoreline ecosystem School of Marine Science and water quality. Riparian lands have suffered Virginia Institute of Marine Science catastrophic losses due to federal water projects College of William and Mary along major river systems. Mining along rivers Gloucester Point, Virginia 23062 and streams has taken its toll on the surround- (804) 684-7380 ing habitat and associated water quality. Mines can intercept the deep water table, disrupting Dr. Carl Hershner, Program Director regional aquifers and reducing stream and spring Dr. Bill Roberts, Editor flows over a large area (Nelson et al. 1991). Published by: VIMS Publication Center Mining also produces chemical contaminants that find their way into streams. This technical report was funded, in part, by the Virginia Coastal Resources Management Program Agriculture and urban development have a great of the Dept. of Environmental Quality impact on today’s riparian lands. Land devel- through Grant #NA97O20181-01 of opers generally clear large areas of shoreline to the National Oceanic and Atmospheric build homes and establish lawns. Urban resi- Administration, Office of Ocean and dences along rivers and streams are often con- Coastal Resources Management, under cerned about floods and property damage. the Coastal Zone Management Act of Therefore, flood control dams are built upstream 1972, as amended. from urban centers, which results in direct and indirect impacts on riparian habitats. Many ri- The views expressed herein are those of the parian wetlands are maintained by annual or authors and do not necessarily reflect the views semiannual flooding, especially those on the first of NOAA or any of its subagencies or DEQ. terrace above the river channel (Johnson et al. 1999). Below the reservoir, the river flow re- gime is altered and traditional riparian systems Commonwealth’s Declared Policy: “to preserve the are destroyed. Above the dam, riparian areas wetlands and to prevent their despoliation and destruc- are lost due to increased inundation and, more tion...” often, increased housing and recreational devel- Printed on recycled paper. opment around the resulting reservoir.

2 Riparian areas offer rich soils and are cleared of major geomorphic zones: (1) erosion, (2) stor- natural vegetation for agricultural development age and transport, and (3) sediment deposition. in many places. Farm landowners continue to The first two zones make up the drainage basin remove more vegetation from the edges of their and the sediment deposition (zone 3) generally cultivated fields in hopes of gaining increased occurs at the lake or ocean into which the water- crop harvest each year, thereby greatly impact- shed feeds (Mitsch and Gosselink 1993). This ing the existing buffer. Streams and rivers that is not to say that erosion does not occur in each border or cross livestock fields are often used of the zones. However, erosion rates are gener- as the primary water source and are often left ally greatest in the upper watershed (zone 1). widely available to the animals. Domestic live- Taking under consideration the effects a resto- stock concentrated in bottomlands for extended ration project would have downstream and on periods destroy riparian ground cover, destabi- the surrounding properties is an important step lize streambanks, and thus increase sediment in determining and categorizing riparian projects. loads to streams (Patten 1998). Livestock also deliver waste material high in nitrogen directly Technology tools such as remote sensing, aerial into the watersource. Each of these practices photographs and Geographic Information Sys- has contributed to the depletion of forested ri- tem (GIS) are helpful in identifying and map- parian buffers, a great loss of diverse wildlife ping riparian areas within an entire watershed. habitat, and increased erosion and nutrient run- Watershed analysis can provide a template for off into streams and rivers. restoration practitioners to use in prioritizing restoration activities. Although the analysis re- Because the benefits derived from riparian sys- quires significant time, money, and personnel, tems are provided by nature without cost, it is experience suggests that watershed analysis pro- difficult to compare the real economic worth of vides valuable direction for managing aquatic and riparian systems with activities, such as agri- riparian resources (Kershner 1997). Once a po- culture and grazing, that have well-defined mar- tential restoration site has been identified, clear ket values. In addition, these more easily quan- goals and objectives must be developed and tified activities receive subsidies that increase should be used to drive the project design. their value and encourage their development (Burns 1984). Restoration projects must be designed with an understanding of: (1) the processes that remove or sequester pollutants entering the riparian Riparian Restoration buffer system; (2) the effects of riparian management practices on pollutant retention; (3) the Landscape ecology is based on the hypothesis impacts of riparian forest buffers on aquatic eco- that the interactions among biotic and abiotic systems; (4) the time necessary for recovery af- components of the landscape are spatially medi- ter harvest of trees or reestablishment of ripar- ated. Not only are the flows of energy, material ian buffer systems; and (5) the effects of under- or species from place to place affected by their lying soil and geologic materials on chemical, hy- locations in the landscape, these flows then de- drological, and biological processes (Lowrance termine the interactions among energy, material et al. 1997). A clear understanding of the and species. Landscape ecology has arisen from landowner’s desires and goals for the project is practical consideration of how ecological ideas also important. could be applied in land management (Malanson 1993). This idea is especially important when The vegetation composition and width will de- considering riparian restoration because the termine the buffer’s effectiveness in trapping potential site is part of an interactive watershed sediment, recycling nutrients and providing wild- network. Management decisions made on any life habitat. Whenever possible, a forested buffer portion of the watershed will affect another por- should be established. Adding trees to a buffer tion or portions, either directly or indirectly, zone can increase the potential reduction of sedi- positively or negatively. ment and nutrients (Figure 2). Plus, a forested buffer can offer more diverse wildlife habitat and Landscape ecology is a useful approach when critical travel corridors for wildlife along water- working to identify and prioritize areas for ri- ways. However, not all riparian restoration plans parian restoration. The location within the wa- will require reforestation. Bank stability is a tershed can help to identify objectives for a po- major factor in tidally influenced areas because tential project. Most watersheds have three of wave action, boat wakes, storms, and rising

3 Buffer Buffer Sediment Nitrogen Phosphorus Width (ft.) Type Reduction % Reduction % Reduction %

15 Grass 61.0 4.0 28.5 30 Grass 74.6 22.7 24.2 62 Forest 89.8 74.3 70.0 75 Forest / Grass 96.0 75.3 78.5 95 Forest / Grass 97.4 80.1 77.2

Figure 2. The Effects of Different Size Buffer Zones on Potential Reductions of Sediment and Nutrients from Field Surface Runoff

sea level undermining trees at the water’s edge. nated riparian zones as eligible for inclusion in It is possible that trees in this situation could the U.S. Conservation Reserve Program (CRP), contribute to localized erosion and destabiliza- in which farmers can be paid for not farming tion (Lowrance et al. 1997). certain environmentally sensitive areas. Most recently, the USDA added the Conservation Res- toration and Enhancement Program (CREP) Management & Policies which provides funding to enhance and protect riparian areas, including fencing-off riparian ar- It has long been known that land management eas from livestock and replanting native trees and conservation management go hand in hand. and grasses. In addition to federal funds and More recently, we have begun to understand the cost-share provided by CREP, qualified landown- implications of farming and forestry on water ers in Virginia can combine CREP with State and quality. As these realizations have emerged, so Chesapeake Bay Foundation cost-share to cre- too have tools to address the evolving needs of ate a 100% cost-share total. Figure 3 outlines the farm landowner. Foremost among those tools several other federal, state and local agency pro- has been the long-running series of U.S. Depart- grams that also offer conservation assistance to ment of Agriculture (USDA) farm programs col- riparian landowners in Virginia. lectively known as the Farm Bill. The Farm Bill currently authorizes about 20 agricultural con- In addition to restoration issues concerning ri- servation programs with a combined funding level parian lands, preservation issues must also be of $2.5 billion per year. Collectively, these pro- addressed. Several options are available to land- grams have significant potential to affect water owners that wish to protect their riparian ar- quality, shoreline stability, fish and wildlife popu- eas. Landowners may wish to protect their prop- lations, and their habitats. And if the trend of erty from the pressures of surrounding develop- recent years continues, public funding for com- ment, undesirable land-use, or from property modity subsidies will continue to decline, and division and sale upon their death. Many op- will be replaced with increased funding for con- tions can provide financial payments and tax servation on agricultural lands. benefits to the qualified landowner. Conserva- tion easements offer one of the best permanent Current riparian management policies have fo- land protection strategies for riparian landown- cused on several issues: (1) widths of riparian ers. Easements can be donated by the land- management zones, (2) retention of live trees and owner, providing tax benefits, or easements may snags within the riparian zone, (3) the extent of be purchased by a qualifying organization. In shade cover, (4) floodplain protection, (5) yard- either situation, easements become part of the ing corridors, (6) erosion protection, and (7) property’s title and the property can be protected nutrient and sediment trapping (Gregory 1997). from undesirable land use. Although conserva- The USDA has specifically recognized the impor- tion easements tend to be permanent, they rep- tance of riparian areas. Proposals have been resent the most significant financial reward made for using riparian vegetation as filters for among the long-term land protection strategies. agricultural nutrients as well as traps for agricultural sediment. The USDA has also desig-

4 NRCS DU-CBF SWCD SWCD SWCD NRCS USFWS SWCD 50% NRCS, 75% NRCS Cost Share Rate *Contact Share Cost 1) permanent easement; payment for easement + 100% cost share for wetland restoration 2) 30-year easement; payment for 75% of easement value + 75% cost share for wetland restoration 3) Restoration Agreement; 10 year agreement (no easement) + 75% of cost share for restoration activity 75-90% 10-year agreement period 75% 5-year agreement period One-time payment of $175 per acre 5-year agreement period One-time payment of $100 per acre 10-year agreement Three options: none 75-95% 10-year agreement NRCS – Natural Resources Conservation Service, (804) 287-1691 Conservation District, (804) 786-2064 SWCD – Soil and Water Service, (804) 694-6693 and Wildlife Fish USFWS – U.S. (804) 977-6555 Department of Forestry, VDOF – Virginia Offers financial incentives to restore or protect wetlands in exchange for retiring marginal agricultural land Offers assistance for wetlands restoration, planting vegetation, livestock fencing, watering systems, and stream crossings. Offers incentive to change streamside land use by planting vegetation, permanent fencing, and installing livestock crossings. Provides cost share to install and maintain suitable grass filter strips along streams. Offers financial assistance to change crop and pasture land use to establish a forest buffer along streambanks. A large-scale land retirement program that offers an annual rental payment plus cost-share to convert environmentally valuable cropland or pasture to suitable grass or tree cover for 10-15 years Offers financial, educational, and technical help to install practices on croplands or livestock areas to improve and maintain the health of natural resources. A farmland management program that helps landowners plan and pay for habitat improvements in associa- tion with active farming. Offers financial assistance to restore waterfowl habitat, install livestock fencing, stabilize streambanks and install buffer strips. Program Name Description Wildlife Habitat Incen- tives Program (WHIP) Partners for Wildlife Conservation Reserve Program (CRP) Environmental Quality Incentives Program (EQIP) Wetlands Reserve Wetlands Program (WRP) Habitat Stewardship Program Stream Protection (WP-2) Grass Filter Strips (WQ-1) Buffer Filter Woodland Area (FR-3) Wildlife Water Quality Water Environmental Protection Figure 3. Conservation Available to Riparian Landowners Figure Programs *Virginia Contact Agency List: DCR – Department of Conservation and Recreation, (804) 786-2121 (804) 780-1392 DU-CBF –Ducks Unlimited–Chesapeake Bay Foundation, (804) 287-1500 Service Agency, FSA – Farm 5 Conclusion

Riparian forest buffer systems are generally ef- For example, Maryland’s Buffer Incentive Pro- fective for control of sediment and sediment- gram had a backlog of applicants when the pro- borne pollutants carried in surface runoff. Con- gram offered landowners a one-time $500-per- sideration of existing riparian forests and link- acre payment to establish and maintain mini- age of forested riparian buffers as continuous mum 50-foot forested buffers. A legislative modi- stream corridors is desirable. However, water- fication to the program lowered the payment to shed-wide implementation of riparian restora- $300 per acre; the result was a steep decline in tion requires tremendous levels of coordination the number of applicants (Chesapeake Bay Com- by multiple partners. mission 1995). A more detailed, formal analysis of economic incentives could help determine Because so much of the protection of riparian what level of cost-share is economical to land- land relies on voluntary and contractual pro- owners in differing land-use scenarios. Some grams, a central element of riparian forest policy relatively minor adjustments to funding levels involves incentives, cost-share programs, fee pay- or structures could result in a significant change ments for land taken out of production, subsi- in the willingness of landowners to participate dized seedlings, and so on. These incentives are in incentive programs. delivered through a host of agents, state and local natural resource agencies, private industry, In The Influence of Forestry upon the Lumber and citizen groups. Pennsylvania’s Streambank Industry, Overton Price (1902) noted that “it is Fencing Program is exemplary in that it provides the history of all great industries directed by fencing to restrict livestock access to streams private interests that the necessity for modifica- free of charge to farmers. This has resulted in tion is not seen until the harm has been done the installation of over 100 miles of fencing. For- and its results are felt.” It is this characteristic estry corporations provide subsidized seedlings of human nature and our society that necessi- to landowners for reforestation, and countless tates awareness of historical changes, anticipa- private businesses and citizen organizations are tion of future trends and the development of more involved in community forest buffer replanting effective approaches to maintain and restore ri- programs. However, the question remains as to parian forests and aquatic ecosystems. The pro- how effective various incentive programs are in tection of riparian systems will not be won sim- meeting the economic needs of landowners while ply by the passage of a law by a county board of maintaining and restoring riparian forests. supervisors or the State Legislature. Pressures for development will continue to increase and The financial benefit a landowners receives can an effective lobby, supported by scientific re- have a significant impact on his or her willing- search, for protecting riparian systems will be ness to participate in riparian forest programs. needed to balance the political influence of in- dustrial and development lobbies.

6 Literature Cited

Brinson, M.M., B.L. Swift, R. C. Plantico, and J.S. Johnson, RR. and S.W. Carothers. 1982. Riparian Barclay. 1981. Riparian Ecosystems: Their Ecol- Habitats and Recreation: Interrelationships in ogy and Status. U.S. Fish and Wildlife Service, the Southwest and Rocky Mountain Region. Biol.Serv. Program. FWS/OBS-81/17, Washing- U.S. Forest Service, Rocky Mountain Forest and ton, D.C., 151 p. Range Experiment Station, Fort Collins, CO. USA. Eisenhower Consortium Bullentin 12:1- Brinson, M.M. and J. Verhoeven. 1999. Riparian 31. Forests. Pp. 265-299 in M.L. Hunter, Jr. (ed). Maintaining Biodiversity in Forest Ecosystems. Kershner, J.L. 1997. Setting Riparian / Aquatic Res- Cambridge University Press, New York. toration Objectives within a Watershed Context. Restoration Ecology 5(4supp): 15-24. Burns, J.W. 1984. Public Values and Riparian Sys- tems. Pp 226-227 in R.E. Warner and K.M. Lowrance, R., L.S. Altier, J.D. Newbold, R.R. Hendrix (eds). California Riparian Systems: Schnabel, P.M. Groffman, J.M Denver, D.L. Ecology, Conservation and Productive Manage- Correll, J.W. Gilliam, J.L. Robinson, R.B. ment. University of California Press, Berkeley. Brinsfield, K.W. Staver, W. Lucas, and A.H. Todd. 1997. Water Quality Functions of Riparian For- Chesapeake Bay Commission. 1995. An analysis of est Buffers in Chesapeake Bay Watersheds. Riparian Forest Buffer Policies in Maryland, Environmental Management 21(5): 687-712. Virginia, and Pennsylvania. Issues and Actions adopted January 6, 1995. Annapolis, Maryland. Malanson, G.P. 1993. Riparian Landscapes. Cam- bridge University Press, Great Britain. Gregory, S.V. 1997. Riparian management in the 21st Century. Pp. 69-85 in K.A. Kohm and J.F. Mitsch, W.J. and J.G. Gosselink. 1993. Wetlands, Franklin (eds). Creating a Forestry for the 21st 2nd edition. Van Nostrand Reinhold, New York. Century, The Science of Ecosystem Manage- Nelson, R.L., M.L. McHenry, and W.S. Platts. 1991. ment. Island Press, Washington, D.C. Mining. American Fisheries Society Special Pub- Johnson, G.D., M.D. Strickland, J.P. Buyok, C.E. lication 19:425-457. Derby and D.P. Young, Jr. 1999. Quantifying Riparian Ecosystems of Semi- Impacts to Riparian Wetlands Associated with Patten, D.T. 1998. Arid North America: Diversity and Human Im- Reduced Flows along the Greybull River, Wyo- pacts. Wetlands 18(4): 498-512. ming. Wetlands 19(1): 71-77.

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