Forest roads and water quality

For more than a quarter century, the US Environmental Protection Agency (EPA) has contended that the most effective way to protect water resources in managed forests is to treat forestry activities as nonpoint sources controlled with Best Management Practices (BMPs). Recently, the Ninth Circuit Court of Appeals in NEDC v Brown ruled that logging roads are point sources of water pollution subject to permitting requirements of EPA’s Phase 1 stormwater program for industrial activities.

Forest policy experts are working on legal and legislative responses to the Ninth Circuit’s decision. Many experts have noted that requiring stormwater permits for logging roads is inconsistent with long-standing EPA regulations and would impose substantial costs and legal risks on landowners, loggers, and forest-based manufacturing in the United States. Higher costs and risks would discourage investment in sustainable forest management and encourage land use change from forestry to other uses with greater impacts on water quality.

NCASI is reviewing and summarizing scientific information about forest roads and their effects on water resources. Key facts include:

  • State silvicultural nonpoint source control programs are highly effective
  • Nationwide, it is estimated that state forestry BMPs are applied nearly 90% of the time (Ice et al. 2010).
  • BMPs provide substantial protection to water quality and aquatic habitat (Williams et al. 2000; Vowell and Frydenborg 2004).
  • Multiple paired watershed studies show that BMPs reduce water quality impacts (e.g., sediment, temperature, dissolved oxygen, herbicides) by 80 to 90% compared to historic practices without BMPs (Ice 2004; McBroom et al. 2008).
  • Certification programs in forestry promote compliance with state BMPs and other water quality regulations (Simpson et al. 2008).
  • Forestlands, including roads, are generally minor sources of sediment compared to other land use activities, including those chosen for stormwater permits. For example, EPA estimates that forestlands produce 1/1,000th the erosion observed for construction sites (USEPA 2005).
  • Many states rank forestry as a minor source of water quality impairment (NASF and SAF 2000).
  • Managed forest watersheds have low sediment losses compared to annual erosion rates from alternative land use activities. 
  • Even though forests represent one-third of the landbase in the United States, they contribute to less than 5% of river and stream miles identified as water quality impaired.
  • EPA WATERS ( identifies a total of 470,437 threatened or impaired river and stream miles, but forestry and other forest activities are identified as a contributor to only about 19,400 of those miles.
  • The most recent data show that forestry has dropped out of the top ten categories (of 23 “Probable Source Group” categories) contributing to impairment (Ice and Beebe 2011).
  • Some water quality standards used to judge impairment may be unachievable in forest watersheds (Ice and Binkley 2003; Ice and Sugden 2003; Ice et al. 2004). For example, some streams wholly within federal Wilderness Areas are listed as water quality impaired (Sommarstram 2009). 
  • Forest road practices continue to evolve and improve. The goal of BMPs for stormwater is to disperse flow onto the forest floor to the greatest extent possible before it reaches a stream (Olszewski and Jackson 2006).
  • BMP surveys in southern states demonstrate that both use and effectiveness show regular improvement (Ice et al. 2010).
  • Road surveys find that improved practices reduce erosion from surfaces, gullies, and landslides (Cafferata et al. 2007; Cafferata and Spittler 1998; Robison et al. 1999).
  • Legacy road conditions are being addressed with ongoing management practices (Cafferata et al. 2007). 
  • Research to understand how to protect water quality has been conducted for nearly a century in the US and provides key lessons (Ice and Stednick 2004).
  • The first paired forest watershed study began in 1909, and by 1960 there were 150 across the US (Ziemer and Ryan 2000).
  • More than 100 studies across the US have tested the effectiveness of forestry BMPs at paired watersheds and other controlled research areas (SAF 2007, map of research).
  • The Watersheds Research Cooperative is finding that fish populations are protected with contemporary forest practices (


Cafferata, P.H., Coe, D.B.R., and Harris, R.R. 2007. Water resource issues and solutions for forest roads in California. Hydrological Science and Technology 23(1‑4):39‑56. 

Cafferata, P.H., and Spittler, T.E. 1998. Logging impacts of the 1970’s vs. the 1990’s in the Caspar Creek Watershed. 103‑115 in Proceedings of the Conference on Coastal Watersheds: The Caspar Creek Story. General Technical Report PSW‑GTR‑168. Albany, CA: USDA Forest Service, Pacific Southwest Research Station. 

Ice, G. 2004. History of innovative best management practice development and its role in addressing water quality limited waterbodies. Journal of Environmental Engineering 130(6):684‑689. 

Ice, G.G., and Beebe, J. 2011. Technical comments on Wildland CPR and EPIC brief on NEDC v. Brown. In Proceedings of the NCASI 2011 Southern Regional Meeting. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc. 

Ice, G., and Binkley, D. 2003. Forest streamwater concentrations of nitrogen and phosphorus: A comparison with EPA’s proposed water quality criteria. Journal of Forestry 101(1):21‑28. 

Ice, G.G., Light, J., and Reiter, M. 2004. Use of natural temperature patterns to identify achievable stream temperature criteria for forest streams. Western Journal of Applied Forestry 19(4):252‑259. 

Ice, G.G., Schilling, E., and Vowell, J. 2010. Trends for forestry best management practice implementation. Journal of Forestry 108(6):267‑273. 

Ice, G.G., and Stednick, J. 2004. A Century of Forest and Wildland Watershed Lessons. Bethesda, MD: Society of American Foresters. 

Ice, G., and Sugden, B. 2003. Summer dissolved oxygen concentrations in forest streams of northern Louisiana. Southern Journal of Applied Forestry 27(2):92‑99. 

McBroom, M.W., Beasley, R.S., Chang, M., and Ice, G.G. 2008. Storm runoff and sediment losses from forest clearcutting and stand re-establishment. Hydrological Processes 22(10):1509‑1522. 

National Association of State Foresters (NASF) and Society of American Foresters (SAF). 2000. A review of waterbodies listed as impaired by silvicultural operations. Bethesda, MD: Society of American Foresters. 

Olszewski, R., and Jackson, R. 2006. Best management practices and water quality. 1‑11 in A Primer on the Top Ten Forest Environmental and Sustainability Issues in the Southern United States. Special Report No. 06‑06. Research Triangle Park, NC: National Council for Air and Stream Improvement, Inc. 

Robison, E.G., Mills, K., Paul, J., Dent, L., and Skaugset, A. 1999. Oregon Department of Forestry Storm Impacts and Landslides of 1996: Final Report. Forest Practices Technical Report 4. Salem, OR: Oregon Department of Forestry. 

Society of American Foresters (SAF). 2007. Water Resources Working Group November Newsletter: Watershed Research Sites. Bethesda, MD: Society of American Foresters. 

Simpson, H., Donellan, J., Duncan, C., and Harrington, S. 2008. Voluntary implementation of forestry best management practices in East Texas: Results from round 7 of BMP implementation monitoring. Lufkin, TX: Texas Forest Service. 

Sommarstram, S. 2009. Wooley Creek Delisting Request.

United State Environmental Protection Agency (USEPA). 2005. Stormwater Phase II Final Rule: Small Construction Program Overview. EPA 833‑F‑013. Washington, DC: United State Environmental Protection Agency, Office of Water. 

Vowell, J.L., and Frydenborg, R. 2004. A biological assessment of best management practice effectiveness during intensive silviculture and forest chemical application. Journal of Water, Air, and Soil Pollution: Focus 4(1):297‑307. 

Williams, T.M., Hook, D.D., Lipscomb, D.J., Zeng, X., and Albiston, J.W. 2000. Effectiveness of best management practices to protect water quality in South Carolina Piedmont. 271-277 in Proceedings of the Tenth Biennial Southern Silvicultural Research Conference. General Technical Report SRS‑30. Asheville, NC: USDA Forest Service. 

Ziemer, R.R., and Ryan, D.F. 2000. Current status of experimental paired-watershed research in the USDA Forest Service. EOS, Transactions, American Geophysical Union 81(48):F380.

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