Adaptive Management – Phase II
Date: 1/19/00
Assessment conducted by: John Cissel, Blue River Staff, Blue River Aquatic Team, Fred Swanson, Paul Bennett, Tere Turner
Question: Develop a road restoration strategy to help meet the aquatic conservation strategy objectives and is integrated with the landscape management strategy.
Information source(s):
1. Wemple, B.C., J.A. Jones, and G.E. Grant. 1996. Channel network extension by logging roads in two basins, western Cascades, Oregon. Water Resources Bulletin 32(6): 1195-1207.
2. Process for developing transportation management objectives applied at the watershed scale. 1997. Roseburg District BLM. 19 p.
3. Flanagan, S.A., M.J. Furniss, T.S. Ledwith, S. Thiesen, M. Love, K. Moore, J. Ory. 1998. Methods for inventory and environmental risk assessment of road drainage crossings. USDA Forest Service Technology and Development Program Report. 45 p.
4. Pilot roads analysis. 1999. Willamette National Forest.
5. Blue River road restoration concept paper. 1999. OSU Geosciences class - advanced field methods in geomorphology and landscape ecology.
6. USDA Forest Service. 1999. Roads analysis: informing decisions about managing the National Forest transportation system. USDA Forest Service Washington DC. FS-643.
7. Jones, J.A., F.J. Swanson, B.C. Wemple, and K.U. Snyder. in press. Effects of roads on hydrology, geomorphology, and disturbance patches in stream networks. Conservation Biology.
8. Madej, M.A. in review. Erosion and sediment delivery following removal of forest roads. Earth Surface Processes and Landforms.
9. Wemple, B.C., F.J. Swanson , and J.A. Jones. in review. Effects of forest roads on sediment production and transport, Cascade Range, Oregon. Earth Surface Processes and Landforms.
10.Wemple, B.C. 1998. Investigations of runoff production and sedimentation on forest roads. Corvallis, OR: Oregon State University. 168 p. Ph.D. dissertation.
Relevant study component: Landscape management strategy - watershed restoration
Background: Attainment of the aquatic conservation strategy objectives in the landscape management plan relies on vegetation management regimes patterned after natural disturbance regimes, various mitigation measures, an aquatic reserve system, and an active watershed restoration program. To date, the vegetation management regimes have been outlined and scheduled into the future with sufficient temporal and spatial detail to support project-level planning, modeling and assessment. However, the road restoration strategy in the landscape management plan contains only general goals and types of projects. There is a need to develop the road restoration strategy in sufficient detail to support project planning and implementation, modeling, assessment, and evaluation of the aquatic conservation strategy objectives.
Road restoration has also become a major public issue and internal concern. Negative effects of roads on a wide variety of watershed and ecological processes have been identified. The existing road system was built based on a large timber sale program, and road maintenance was funded from timber sale receipts. With the sharp decrease in timber sales a huge backlog of unfunded road maintenance needs has arisen. Meanwhile, numerous stocks of anadromous fish species have been identified as threatened species, although none have been listed in the Blue River watershed. National guidance on road analysis has recently been issued in response to these issues.
Recent research in the Blue River watershed and elsewhere has clarified the effects of roads on hydrology, geomorphology, disturbance patches in stream networks, sediment production, and the potential benefits of road restoration. Results from these studies identify aspects of the watershed and road system that should be analyzed to assess risks to aquatic ecosystems.
Evaluation: The road restoration strategy ranks each road by a set of aquatic risk indicators and by ratings of future human use needs. Data to conduct these rankings were assembled from a field inventory and from GIS analyses. Aquatic risk indicators were summed by watershed processes (mass movement risk, fine sediment risk, hydrologic interaction risk), and aggregated into one summary rating for each road. Ten subdrainages were also ranked in terms of aquatic ecosystem risks. A composite aquatic risk rating was formed based on both the individual road and the subdrainage rankings.
Future human use rankings were also summed and categorized based on the degree of need for future access. These ratings determined whether the road should remain on the system or be removed, and for system roads determined whether they should remain open or be closed for future use. Roads slated to remain open were then further screened by their aquatic risk rating. Roads determined to be a high risk to aquatic ecosystems were changed to a closed status. The aquatic ratings were also used to determine the priority for converting roads to non-system or closed status (ensure self-maintenance), and to establish maintenance priorities for open roads.
Results of the analysis are displayed as a series of maps depicting road and subdrainage rankings and restoration priorities, individual road and subdrainage ranking spreadsheets, and analysis process documentation. Results will be displayed on the Blue River Landscape Study web site as well as hard copy.
Recommendations: The draft road restoration strategy should be reviewed and refined and then incorporated into the landscape management strategy, the evaluation of the aquatic conservation strategy objectives, and future monitoring, modeling and research. The strategy identifies road restoration priorities for individual roads and by subdrainage.