5. Road maintenenace and upgrading: To protect existing roads from future erosion, active roads need to be maintained and, in many cases, upgraded. In erodible, landslide-prone areas, such as the slopes and sub-basins of South Fork Mountain, it is highly recommended that road upgrading techniques be agressively employed on existing road systems to "storm-proof" them before the next serious flood. Many roads, especially those on private forest lands, were built at a time when construction standards were much lower than today. For this reason, stream crossings and other elements of the road system are currently "under designed" for the 50-year or 100-year flood and are highly susceptible to failure by toady's standards. All the following basic measures are designed to reduce the yield of sediment from roaded and managed lands.
A. Roads that are needed for the final transportation plan should be proactively treated to protect against accelerated erosion during future large storms and floods. This includes both upgrading drainage structures, improving surface drainage and removing potentially unstable fills and sidecast.
B. A program should be instituted to systematically upgrade all undersized or poorly constructed drainage facilities. This includes the replacement of all Humboldt log crossings, upgrading all culverted stream crossings to the 50- or 100- year flow capacity, and replacing selected fill crossings with bridges. "Under-designed" roads and stream crossings need to be upgraded if these roads are to remain open and a part of the maintained road network.
C. A program should be initiated to eliminate the high potential for stream diversion at all stream crossings where substantial erosion and sediment yield could result from culvert plugging during a flood.
D. Additional recommended road upgrading actions may include: surfacing (rocking or paving), outsloping road surfaces (and removing ditches), adding rolling dips, armoring eroding ditches, installing additional ditch relief culverts, excavating potentially unstable fills, installing oversized culverts with trash racks in selected stream channels known to carry substantial debris, replacing large culverts with bridges in unstable areas, rip rapping bridge abutments, converting many seasonal roads to temporary road status (in which stream crossing fills are excavated between periods of forest entry), and instituting winter patrols and maintenance (see also CDWR, 1979; 1982b).
8. Road closure and decommissioning: The large number of roads, especially on private lands, which are inactive and no longer needed for active forest management should be decommissioned. Many of these roads have been abandoned and some are largely overgrown. Roads which are currently "active" but are not needed for current management should also be "proactively closed" until they are again needed for land management. Both road upgrading (see above) and road obliteration need to become important land management tools employed by private industry if watershed values and resources are to be protected in the South Fork Trinity River basin.
A. All roads which have been blocked, are overgrown, are currently abandoned or which are not annually maintained should be closed by excavating stream crossing fills and unstable road and landing sidecast.
B. Roads that will not be needed for periods of 10 to 20 years should be put-to-bed by removing stream crossings, seeding, planting, decompaction, removing unstable fill and outsloping (see also CDWR, 1979).
C. This proactive road closure treatment should be applied to all abandoned road systems, even those that have been abandoned for many years and are currently overgrown.
Assessing and Mitigating Cumulative Watershed Effects
"There are unquestionably numerous watersheds in the Trinity Basin-portion of the Forest that have suffered cumulative effects and are in degraded condition" (USDI, 1990, p. 3).
There are a number of sub-watersheds in the South Fork Trinity River basin that have been analyzed for, and currently display, cumulative watershed effects. On USFS lands these watershed areas include the East Fork South Fork Trinity River, the Upper South Fork, Rattlesnake Creek, Hidden Valley, Butter Creek, Upper Hayfork Creek, Gulch and Hyampom" (Haskins and Irizarry, 1988) as well as Grouse Creek (Mike Furniss, personal communication). Special management practices are likely to be required in these areas. "It must be recognized that some watersheds may already be at risk and that proposed levels of timber harvest will need to be modified, based on project level analyses" (Haskins and Irizarry, 1988).
1. The following changes in cumulative effects assessments should be considered for implementation on USFS lands in the South Fork Trinity River basin.
A. In cases where watershed conditions have been found to be in degraded condition during habitat surveys, the threshold of concern must be lowered to match watershed and channel conditions (USDI, 1990).
B. USFS TOC values for sensitive watersheds should be re-evaluated on a basin-by-basin basis, and matched with observed stream channel conditions.
2. Private land cumulative effects assessment should be modified to recognize the condition of heavily degraded watersheds, such as Grouse Creek and other South Fork Mountain tributaries, and provide meaningful and substantial restrictions or mitigations for proposed land use operations in these sub-watersheds.
A. Some measure of protection from cumulative watershed effects should be developed and implemented for operations on sensitive private forest lands on South Fork Mountain and elsewhere in the South Fork Trinity River basin. These improved cumulative effects "BMP's" for private lands need to address the rate, spatial location, and timing of allowable harvesting on a watershed-wide basis, as well as harvesting on specifically identified "sensitive terrain," including potentially unstable inner gorge slopes.
B. Road network planning, and recommendations for upgrading and decommissioning should better reflect the sensitivity and erosional condition of each sub-basin, its streams and hillslopes and the depleted status of downstream fisheries.
Land Use Regulations
A dual standard of forest practices has been in effect in the South Fork Trinity River watershed since the mid-1970s; one for public forest lands and another (less restrictive and less protective to downstream resources) for private timberlands. The reaction of the landscape to this dual standard continues to represent a serious threat to existence and recovery of the basin's severely depleted anadromous fishery.
"Recovery of the fish resource is dependent on good land management practices and improvement work on both National Forest System and private lands" (MSSDP, 1985, p. 14).
A. New standards for public lands in riparian areas and "key watersheds:" Since the mid-1970s, the Forest Service has significantly modified forest practices in response to observed watershed conditions and the results of studies relating land management with subsequent watershed erosion and channel degradation. More recently, much more protective riparian standards and guides have been proposed for all federally managed areas in Washington, Oregon and northern California, including lands in the South Fork Trinity River basin administered by Six Rivers and Shasta-Trinity National Forests. As a result, future forest management appears destined to be much more protective of watershed processes and aquatic resources than in the past, and efforts are already underway to protect and restore damaged areas and key fish habitat.
1. New riparian standards and guides for National Forest lands are currently in draft form and will soon be formalized (FEMAT, 1993). These protection and restoration measures should be implemented as soon as is feasible.
A. Watersheds to protect first: Key watersheds and salmonid refuge sub-basins should be reserved and secured through application of protective management practices and restoration. These basins include the East Fork of the South Fork (and its tributaries Prospect and Dark Canyon Creeks), Smokey Creek, Silver Creek, Plummer Creek, Eltapom Creek, Butter Creek, Rattlesnake Creek, and Madden Creek (Six Rivers National Forest). Watershed protection and restoration should be focused first on these refuge basins where there are diverse and or relatively healthy salmonid populations.
B. Watershed protection measures: Road densities should be reduced to a level consistent with planned land uses and the objective of protecting and restoring aquatic habit and anadromous fish populations. Inventorying and implementing improved riparian protection, planning and implementing road obliteration and selective road upgrading should be prioritized to proceed first from the key or refuge sub-watersheds (identified above), and then into adjacent basins where recovery of fish stocks is anticipated to follow (see also recommentations for watershed restoration, below).
2. Standards and regulations for private land management need upgradingPrivate land forest management has historically been much less protective of on-site and off-site resources than public land management in the South Fork Trinity River basin.
"Until only recently, the public has been more concerned with the administrative and enforcement by CDF [California Department of Forestry and Fire Protection] of the forest practice rules than with the adequacy of the rules, themselves" (LSA, 1991).
The most crucial remaining threats to downstream fishery resources in the South Fork Trinity River basin, stemming from upslope and upstream private land forest management, come from three sources.
First, roads on private forest lands are not required to be maintained for more than the life of the timber harvest plan, typically three years. Beyond that time, roads can be, and often are, summarily abandoned with little regard to the subsequent risk of culvert plugging, stream crossing failures and road-related landsliding.
Secondly, although there are some general descriptive techniques for "assessing" of "identifying" cumulative watershed effects in the Forest Practice Rules, the procedure does not result in needed modification of land use practices. The procedure is qualitative and subjective. The existing rules do not work well in watersheds "where sensitive site conditions exist or where sensitive physical or biological resources are at risk" (Kier et al., 1992, p. 2). The Forest Service, controlling 82% of the basin, has developed procedures for considering private land actions when assessing cumulative impact analysis for their own management plans and proposals. Cumulative watershed analyses are performed for subwatersheds and management is restricted to acceptable levels (Haskins, 1981).
Thirdly, many thousands of acres of private land was logged and roaded in the 1950s and 1960s under little or no land use regulation. Many roads, in particular, are under-designed and poorly located, and most of those on private lands are abandoned and largely over grown or unmaintained. This legacy of abandoned, poorly constructed roads represents a significant and immediate threat to the downstream fisheries.
1. Regulations are needed to spur solution of the most significant remaining weaknesses in land management practices that still threaten the viability and recovery of wild fish stocks of the South Fork Trinity River basin.
A. Complete erosion inventories are needed for all private forest lands within the South Fork basin, especially on South Fork Mountain, to address likely future erosion and sediment yield from lands which were heavily managed in the past. These inventories, and the associated erosion prevention work, are urgently needed and, since work has not been voluntarily implemented, might best be initiated and accomplished through specific regulation.
B. All private and public forest roads should be maintained for their entire useful life, until they are no longer needed. This includes annual and storm period inspections and maintenance of roads, drainage structures and fills. Only a limited period of road maintenance are currently required under California's Forest Practice Rules.
C. All roads no longer needed for active forest management should be "closed" (decommissioned) using accepted erosion-prevention practices. These practices include excavating unstable fill materials, completely excavating stream crossing fills, providing permanent surface drainage and revegetation. Other than for designated temporary roads, there are no state regulations which currently require unmaintained or abandoned forest roads to be proactively closed in this manner. Instead, roads are often just blocked or barricaded, or left to grow over with vegetation.
D. More protective forest practice regulations are needed for private lands in the western third of the basin, on lands draining South Fork Mountain, that have high-to-extreme erosion hazard ratings, or that involve "sensitive" or potentially unstable watershed areas or steep inner gorge slopes. Meaningful cumulative effects analysis and mitigation, and improved regulations and practices for timber management, are needed for these areas (see above).
3. Rule Interpretation and EnforcementTo be effective in protecting and restoring a vaible fisheries resource in the South Fork Trinity River, "strict land use regulations must accompany an extensive watershed management program. The regulations must protect the soil to such an extent that no increase in the sub-basin's sediment yield results" (FKA, 1980). While this may be a difficult goal to obtain, it is important for future land use to be significantly more protective of the basin's riparian and aquatic resources than has been the case in the past.
A. In the South Fork Trinity River basin, the Forest Practice Act and associated forest practice rules should be interpreted and applied by the Department of Forestry and Fire Protection, and other reviewing agencies, to allow for the maximum possible protection of downstream aquatic and fisheries resources. The rules often allow for a great deal flexibility in their interpretation and application, and this flexibility should be employed to provide for needed resource protection in this sensitive watershed.
The application of restrictive measures seems entirely appropriate in a watershed where stream habitat is severely degraded, whose once noteworthy salmonid populations are now at a fraction of their historical levels, and where residual salmonid stocks are now at risk of extinction.
Introduction
Since the 1970's, resource specialists familiar with declining watershed, fisheries and water quality conditions in the South Fork Trinity River have called for widespread upland erosion prevention and rehabilitation to reverse the trend. Assessments for federally managed sub-basins have only recently been undertaken. Approximately 75% of tributary basins in watershed, virtually all under USFS management, have now been inventoried for potential sediment sources. Proposed treatments concentrate heavily on road closure, road upgrading (including treatments at stream crossings and culverts) and erosion control work along roads and in stream channels. As of 1993, little implementation outside of emergency fire rehabilitation, had occurred. Recent funding for 1994, and perhaps for additional years, promises increased restoration work in protecting and restoring USFS watersheds.
In spite of some administrative and technical shortcomings in the USFS assessments and subsequent restoration efforts, the intent of the program is sound. There is no question that the South Fork Trinity River watershed, particularly in extremely sensitive key tributary sub-basins (see above listing), urgently needs to be inventoried for all potential future sediment sources, prioritized for cost-effective treatment, and aggressively treated using established erosion control and erosion prevention techniques.
With the exception of a pilot inventory project in the Grouse Creek basin undertaken by Six Rivers National Forest, no watershed assessment work has been performed on sensitive or potentially unstable private forest lands in the South Fork Trinity River watershed. This is a serious omission and shortcoming that needs to be addressed in the near future. Failure of private landowners to accept and recognize the importance of future sediment production from their lands will further impact the long term survival and potential recovery of aquatic habitat and anadromous fish populations in the South Fork basin.
Implementing the following recommendations and suggestions will ensure that future watershed assessments are of high quality, that the most critical sediment production sites are treated in a cost-effective manner, and that the greatest benefit to fisheries resources is derived with the available funds. Chapter 16 continued