Programmatic Environmental Assessment Forest-Wide Erosion Abatement USDA Forest Service Shawnee National Forest

Transcription

1 Programmatic Environmental Assessment Forest-Wide Erosion Abatement USDA Forest Service Shawnee National Forest Alexander, Gallatin, Hardin, Jackson, Johnson, Massac, Pope, Saline, Union and Williamson Counties, Illinois February 2016 Introduction The USDA Forest Service is proposing to abate areas of soil erosion occurring on National Forest System (NFS) lands of the Shawnee National Forest (Forest) through the construction of erosion-control structures. On the Forest these areas of erosion contribute, or will contribute, sediment and nutrients to the streams, rivers and reservoirs within and flowing from the Forest. Soil erosion in the watersheds of reservoirs used for municipal drinking-water supplies, such as Kinkaid Lake, Cedar Lake and Lake of Egypt, has contributed substantial amounts of sediment and nutrients to these reservoirs, reducing capacity and accelerating their eutrophication or aging. Sediment from areas of soil erosion, as well as eroding streambanks, degrades and destroys highquality fish and aquatic invertebrate habitat and reduces water quality. This proposed action is consistent with the 2006 Shawnee National Forest Land and Resource Management Plan (Plan, page 23). We have prepared this environmental assessment in compliance with the National Environmental Policy Act and other applicable federal and state laws and regulations. The analysis described herein is a summary of the data, methodology, analysis and findings set forth in the record. We intend for this assessment to be an analytical, science-based document that focuses on the issues most relevant to disclosure of environmental effects [40 CFR (b); (b), (c)]. We disclose the direct, indirect and cumulative environmental effects that might result from implementation of the proposed action and alternatives. Additional documentation, including the resource specialists working papers, is filed in the project record located at the Hidden Springs-Mississippi Bluffs District Office, 602 N. First Street, Vienna, Illinois, and is available on the Forest website. Background One goal of the Forest Plan is to maintain and/or enhance soil productivity, water quality and the integrity of riparian ecosystems and water-supply watersheds across the forest. The proposed activities work towards meeting the Plan goal of Soil, Water, and Air Management: Soil, water and air resources are critical to the health and well-being of the Forest and natural environments of southern Illinois. Some of the most important areas on the Forest are the riparian zones of rivers, streams and lakes. These riparian ecosystems are characterized by abundant speciesdiversity, high densities of species and populations and ample productivity. Water quality is especially important in watersheds that supply municipal drinking water. Soil productivity, water quality and the integrity of riparian ecosystems and water-supply watersheds will be maintained and/or enhanced through non-point water-pollution control methods found in the best-management practices supported by state and federal agencies and coordinated with the US 1

2 Environmental Protection Agency. These practices are incorporated into Forest-wide and specific management standards and guidelines, or incorporated by reference (page 23). On the Forest we have located areas of erosion typically what would be described as gullies and sites with substantial erosion potential such as failing streambanks along and within streams and reservoir watersheds. Historic and current land use within a watershed, such as clearing and farming highly erodible soils, concentration of water flow and construction of poorly designed and maintained roads, as well as disturbances within and along streams, such as channelization and gravel mining, have generated a substantial loss of soil via erosion. These types of disturbances and their long-term effects continue to occur within the streams and rivers of the Forest today. Many of these problems occur on lands far upstream of the Forest but have effects that are seen up and downstream of the site of disturbance and on Forest land. Other disturbances are a result of decades-old land use of which we are now seeing the full effect. Without abatement these sites will continue to erode soil. Surveys to locate areas of erosion are currently underway in the Kinkaid Lake watershed in Jackson County as part of the Kinkaid Lake Watershed Restoration Project. Additional surveys are being conducted on NFS lands above Cedar Lake in Jackson and Union Counties. We have located areas in Hutchins Creek in Union County and Big Creek in Hardin County where severely eroding streambanks are not only contributing sediment and nutrients to the stream but are threatening public roads and electrical powerlines. Proposed Action We propose to abate most areas of erosion using a suite of standard techniques and structures that are widely applied for stabilizing erosion features such as gullies and eroding streambanks, as well as unique, engineered structures for large complex areas of erosion (see Appendix). These structures would be of the same or similar design to erosion-abatement structures that have successfully been used or approved by the Natural Resources Conservation Service (NRCS) or other state and federal agencies. These structures vary in size and materials depending on the size and severity of the erosion area and site-accessibility. For example, techniques utilizing hand tools and naturally occurring materials, such as small or downed trees, would be used to build erosion-control structures at sites that are difficult to access and are of small to medium size. Larger equipment and quarry rock could be utilized to build structures at sites of greater size or severity and are accessible from roads or trails. Across the Forest all known erosion sites, as well as erosion sites found in the future, are proposed for treatment. Priority would typically be given to sites with the greatest amount of erosion and greatest potential for erosion, or to sites within the water-supply watersheds of Kinkaid and Cedar Lakes and Lake of Egypt. After installation of a structure, monitoring, maintenance and repair would be done to prevent failure of the structure. Monitoring will coincide with periodic reviews of the assumptions, data and analysis on which the responsible official will base his decision. Decision Framework Based on the environmental analysis, including the project record, the responsible official will decide whether or not to implement the proposed action. 2 P a g e

3 Effects of Implementing the Proposed Action At each location identified as an erosion area requiring action, the protocol in the table below would be followed to ensure that the placement of erosion-abatement structures does not have adverse environmental effects on adjacent resources. This protocol was developed by the project interdisciplinary team to ensure the protection of resources. Following this protocol, there would be no effects related to water, soil, or air, to sensitive plants or animals, or to any heritage resources. An additional environmental analysis will be required if the circumstances of a future erosion-abatement project prevent its approval following performance of the site-clearance protocol. Erosion Abatement Protocol Sensitive Plants Sensitive Wildlife Heritage Resources Watershed Resources Engineering A Forest botanist will survey the proposed abatement site for the presence of federally listed or other sensitive plants. If any are present, they will be avoided. To prevent the spread of invasive plants, tools and equipment will be cleaning prior to entering or exiting the abatement site. A Forest wildlife biologist will survey the proposed abatement site to identify the potential for adverse effects on wildlife. These potential adverse effects will be prevented by design. A Forest archaeologist will survey the proposed abatement site to determine the presence of eligible resources. If any are found, they will be avoided. A Forest watershed specialist will survey the proposed abatement site to ensure the prevention of damage to protected resources, such as hydric soils. Identified resources will be protected by avoidance. A Forest engineer will survey large proposed abatement sites to determine the location of access routes. The engineer will also approve the design of any large structures required to abate complex erosion areas. All proposed activities are consistent with the Forest Plan and all applicable laws and regulations. Responsible Official: Tim Pohlman, District Ranger Contact: Paul Widowski Shawnee National Forest 602 N. 1 st Street Vienna, IL (618) pwidowski@fs.fed.us The U.S. Department of Agriculture is an equal opportunity provider and employer. 3 P a g e

4 Appendix Example Erosion Control Structures 4 P a g e

5 Gully stabilization structures Figure 2. Plan sheet for non-living stockade checks for woodland gullies. (Courtesy of NRCS) 5 P a g e

6 Figure 3. Photo of Non-living Stockade Checks for Woodland Gullies after installation. (photo courtesy of NRCS) 6 P a g e

7 Figure 4. Plans sheet for log weir checks for woodland gullies. (Courtesy of NRCS) 7 P a g e

8 Figure 5. Photo of log weir checks for woodland gullies after installation. (photo courtesy of NRCS) 8 P a g e

9 Stream bank stabilization structures Figure 5. Vegetated rock wall (NRCS 2007, TS-14M) 9 P a g e

10 Figure 6. Plan sheet for stone toe protection. 10

11 Figure 7. Photo of stone toe protection placed along Big Creek, Hardin County, several years after installation. 11