A combination of environmental, social, and economic pressures drives the need for watershed-scale restoration whether a project site is in an urban or rural setting, yet some of these pressures are unique to or magnified in an urban landscape.

Often, communities hope to mitigate for these problems through stormwater management efforts alone, especially through enforcing regulations requiring stormwater detention basins in a developing landscape. Yet these partial solutions are inadequate to restore the watershed. Instead, effective watershed-scale restoration requires an integrated solution, which includes stormwater management, stream restoration, wetland restoration/creation, and riparian buffer restoration/creation.

Stormwater management efforts focus on creation of adequately sized permanent detention basins to retain stormwater and slowly release it. While detention basins often are just grassy areas that are regularly mowed, sometimes they are made to be more natural systems that not only capture, retain, and gradually release stormwater, but also improve water quality by retaining it in a natural wetland system that removes some of the pollutants.

Within the last 10 years, natural resource agencies throughout the United States have generally accepted a relatively new approach to stream restoration—the natural-channel design approach—because it results in effective long-term restoration of impaired riparian systems. The idea of natural-channel design has been around since the early 1980s, when hydrologist David L. Rosgen, Ph.D., combined decades of research into one common goal: to help degraded and channelized streams reach a state of equilibrium via natural methods instead of over-engineering with concrete, rip-rap, and gabion baskets.

In the urban context, wetland restoration is difficult because of economic and social issues. Usually wetland restoration requires a large area, yet land values and social perceptions create pressure to minimize wetland areas. In many developed areas, there may have been wetlands at one time, but these have been drained by ditches. Restoration may involve filling ditches along with planting native vegetation to intercept rain and retain water on the site, thus allowing the area to return to its natural wetland state.

The riparian buffer consists of floodplains, uplands, and/or upland slopes, which play an important role in water recharge and absorption of floodwater. Yet these buffers often become degraded or eliminated over time through natural processes, such as river down-cutting, or development. Depending on the topography of the site, riparian buffer restoration may involve reconnecting the stream to the floodplain by excavation and earth movement to lower the elevation of the floodplain and/or planting native vegetation to intercept rain and retain water on the site.

A painstaking process

The process of analyzing, developing, and implementing an effective watershed-scale restoration plan involves a number of players—owner, project team, permitting agencies, and the community—and a painstaking series of steps.

Outreach to the community is vital to the success of the project. Stakeholder meetings identify additional issues and concerns that need to be addressed and identify areas of potential community involvement. The educational component fosters understanding of watershed restoration concepts and acceptance of the approaches to be used in the project.

The project team undertakes a watershed assessment and inventory to evaluate the historic uses of the land in the project area and related environmental issues. In the process, the team delineates drainage patterns and basins; land use/land cover; zoning; utilities; stormwater flow paths; and existing stormwater, conveyance, and control structures.

A survey of natural features provides a deeper understanding of the watershed. These include existing vegetation, soil types and infiltration rates, wetlands, floodplain areas, steep slopes, and other environmentally sensitive areas. The team benchmarks existing conditions against a reference watershed and identifies constraints and opportunities for restoration.

The stream assessment looks in-depth at the characteristics of the stream itself, in particular, existing climate, hydrologic, and water quality data; channel dimension, pattern, and profile; and the aquatic life and non-living materials found in the stream.

Thanks to the availability of sophisticated hydrologic computer modeling programs, the team can accurately model existing conditions to identify and analyze stormwater control alternatives.

A stormwater restoration concept plan provides information needed for a local reviewer to evaluate the proposed solution. As such, it documents the results of the topographic survey and the hydrologic analysis, including downstream effects of the project. It presents a preliminary stormwater management system design and layout, taking into account natural vegetation systems. Similarly, the stream restoration concept plan outlines conceptual designs for restoring the stream channel and riparian buffer.

Based on input from the owner, reviewers, and other stakeholders, the final stormwater site plan and stream restoration design refine these concepts, providing the "blueprint" for the project. The stormwater plan includes a detailed site plan, erosion and sediment control plan, natural vegetation systems design, and another essential component—an operations and maintenance plan. The final stream restoration design serves as the permitting document for the land disturbance permit, NPDES II permit, 404 wetland permit, 401 water quality certification, and FEMA no-rise certification.

A ground-breaking project

The city of Atlanta is nearing completion of its first 319(h) project to be funded by the U.S. Environmental Protection Agency (EPA)—the restoration of Candler Park Brook from a straight, concrete-lined conveyance to a natural state along with restoration of its watershed. Environmental Services Inc. (ESI), was selected to restore and construct an urban stream channel located in the Candler Park Golf Course located in East Central Atlanta. Park Pride, a non-profit organization working in a public/private partnership, was contracted by the city to facilitate implementation of the project.

The $875,000 project is funded by a 319(h) grant from the EPA and Georgia Environmental Protection Division ($525,000 in grant funds) to the city of Atlanta ($350,000 in local community bond match). This project is ground-breaking not only because it is the first Atlanta 319(h) project to be funded by the EPA, but it is also among the first to forge partnerships on water issues between the city of Atlanta and EPA professionals. This partnership is particularly timely as Atlanta develops solutions for combined sewers and wastewater treatment.

The project readily serves as a model for other watershed groups applying for 319 funding from the EPA. It also highlights how local volunteers can come together to improve their neighborhoods.

In 2004, Park Pride contracted ESI for a stormwater management plan for Candler Park Brook and its associated tributaries. Flooding had been a problem for decades when sudden heavy downpours or slow steady rains have occurred. This is due in part to the flumed or confined nature of the streams located on the property.

In the late 1920s, streams located within the park were piped via sanitary sewers and concrete flumes in an effort to control the stormwater. This procedure worked fairly well in that the water was moved from "point A" to "point B" within the flumes and pipes, but the natural state of the stream was lost and the park still flooded.

It was clear from the assessments and analysis of the watershed that an integrated restoration approach was necessary. Thus the ESI team's solution combined several elements of stormwater management and natural-channel stream restoration, including creation of four separate detention basins, ranging in area from perhaps 200 square feet to 8,000 square feet, the largest being a wetlands system; use of the golf course itself as a floodplain; restoration of the riparian buffer to retain and slow the flow of rain water; and natural-channel stream restoration. The plan was accepted by the community, including avid golfers, who fully understood the effects of the design on the "play" of the course.

In total, approximately 1,420 tons of natural boulders were used to construct control structures, including 20 cross vanes, which are horseshoe-shaped rock structures that deflect water from the banks; 13 j-hooks, which serve the same purpose at river-bends; and six step pools, which use boulders to control the flow of water as the stream descends the gradient. Approximately 1,900 linear feet of stream channel was day lighted, that is, brought back to the surface where it had previously been run underground through pipe and allowed access to its floodplain, except under the playground.

This past fall, final adjustments were made to structures in the stream channel. Planting will be completed this winter. Shortly after stream restoration was completed, small schools of fish were found in the pools and glides, which had not seen fish for more than 40 years—living evidence of what natural-channel stream restoration can accomplish in a very short time.

Steven M. Jones, Ph.D., is director of the Riverine Division and vice president of Environmental Services, Inc., in Atlanta. Prior to joining Environmental Services, Jones served on the faculty at Clemson University. He has 33 years experience as a vegetation and landscape ecologist specializing in the areas of natural stream morphology restoration, landscape modeling, ecological land classification, vegetation ecology, and soils.

Online resources

Candler Park Brook, www.candlerpark.org
Environmental Services, Inc., www.esinc.cc
Georgia Environmental Protection Division, www.gadnr.org
Park Pride, www.parkpride.org