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I ELTAPOM CREEK WATERSHED I I I I I I I I I Don Allan I NATURAL RESOURCES SERVICES REDWOOD COMMUNITY ACTION AGENCY

I 904 G. ST., EUREKA, CA 95501 I DECEMBER, 1998 I I I I I I I I I I I I I I I I I I I I I

I TABLE OF CONTENTS ABSTRACT ...... 3 INTRODUCTION ...... 3 I BACKGROUND ...... 4 LOCATION ...... 4 FIGURE 1. LOCATION MAP ...... 5 FIGURE 2. Road Survey Sites Map ...... 6 I OBJECTIVES ...... 7 WATERSHED LAND USE ...... 7 ELTAPOM CREEK FISHERIES ...... 7 WATERSHED CHARACTERISTICS ...... 8 I WATERSHED DISTURBANCES ...... 11 PROCEDURES ...... 12 RESULTS ...... 12 Road Related Erosion Surveys ...... 12 I Roads Accessing Private Lands ...... 13 4N09 Road (Power line Road), west of 5N60 ...... 13 4N09 Road (Power line Road), east of 5N60 ...... 20 Sierra Pacific Roads ...... 24 I Trinco Investment Company Roads ...... 24 Skunk Ranch Road ...... 25 USFS Roads ...... 26 4N09/ Mi. 1.65 Spur Rd ...... 26 I 4Nll ...... 26 4N11G ...... 26 4N24 ...... 27 4N24B ...... 27 I 4N25 ...... 27 4N25B ...... 28 4N25C ...... 28 4N25D ...... 28 I 4N25E ...... 28 4N27 ...... 28 4N27A ...... 29 4N34 ...... 29 I 4N34A ...... : ...... 29 4N41 ...... 30 4N41A ...... 30 4N43, 4N43A, 4N43B ...... 30 I 4N47 ...... 30 4N49 ...... 30 5N09 ...... 31 5N60 ...... 31 I 5N60G ...... 31 5N60H ...... 31 COST ESTIMATES and PRIORITY LIST ...... 32 SUMMARY ...... 33 I REFERENCES ...... 35 APPENDIX 1 ...... 37 Culvert Sizing Procedures ...... 37 Culvert Sizing - 4N09 Rd ...... 38 I TABLE 1. Eltapom Watershed Roads ...... 44 TABLE 2. Precipitation at Hyampom, Hayfork, and Big Bar ...... 45 TABLE 3. Precipitation Duration - Frequency for Hayfork and Hyampom ...... 46 I TABLE 4. Annual Flow Extremes, South Fork Trinity River below Hyampom ...... 47 I APPENDIX 2, Eltapom Creek Road Survey Photos ...... 49 I I I I I I I I I I I I I I I I I I I I I I I ABSTRACT I

I A project to reduce sediment input to Eltapom Creek from private lands and their access roads was funded by the Trinity River Restoration Program. In Phase I, road-related I sediment sources were identified, treatments were prescribed, and sites were prioritized for treatment. Phase II of the project was to be the implementation of erosion control treatments at priority sites. Due to a lack of funds, only Phase I was implemented. Based I on information gathered in Phase I, an application t o fund Phase II was submitted to the California Department of Fish and Game's SB 271 program. This report presents the I fi ndings, priority site list , and action plan based on the erosion source survey. I I INTRODUCTION On March 17, 1998, Redwood Community Action Agency (Natural Resources Services division) entered into Agreement No. TFG 97-03A, a watershed improvement project in the I Eltapom Creek watershed in the South Fork Trinity River basin, aimed at identifying and treating road related erosion problems on private land. This project was funded by the I Trinity River Fish and Wildlife Restoration Grant Program and administered by Trinity County. One objective of the restoration grant program is to fund projects which address I measures to reduce and prevent erosion in tributaries of the Trinity River in order to facilitate stable ecosystems and recovery of declining stocks of salmon and steelhead.

I While public lands have funding through government appropriations to maintain roads, albeit at reduced levels in recent years, private landowners often lack the necessary funds I and/ or means to maintain roads. The APPLE Eltapom project was intended to identify erosion problems on private lands and their access roads, and to assist landowners in I treating those problems. While the focus of the project was erosion problems on private lands and their access roads, Forest Service roads were reviewed to assess the relative I contribution of sediment from public versus private roads. One road stood out as having the most significant erosion problems - the 4N09 or Power Line Road. This road received the I most detailed surveys and is the main source of controllable sediment production in the watershed. I

I 3 I

BACKGROUND I Eltapom Creek, a South Fork Trinity River tributary, is a highly productive steelhead trout I (Oncorhynchus mykiss) producing stream. Eltapom Creek also provides cool water to the South Fork Trinity River during the late summer when the South Fork water temperatures rise to levels that are potentially unhealthy to salmonids. Sediment input that causes I channel aggradation and widening threatens to increase solar exposure and raise water temperatures in these cold water refugia tributaries. Upslope sediment control is important I to maintain the integrity of the riparian zone and deep pools that provide these sources of cool water. I

Erosion control in Eltapom Creek is important for two reasons: 1) to protect one of the most productive spawning areas in the South Fork Trinity River basin; and 2) to protect one of the I South Fork Trinity River's sources of cool water which is vital to summer rearing habitat in the South Fork. I LOCATION I Eltapom Creek enters the South Fork Trinity River at river mile 25.4. The mouth of Eltapom Creek is approximately four miles downriver from the community of Hyampom, I Trinity County. The watershed is surrounded by Underwood Mountain on the west, Chaparral Mountain on the north, and Hyampom Mountain on the east. Eltapom Creek is I located between Hyampom and Burnt Ranch on the east side of the South Fork of the Trinity River and the upper watershed is accessed from the 5N60 Rd., which is the Forest Service designation for Underwood Mountain Road out of Burnt Ranch on Highway 299. The I 5N60 road enters the Eltapom Creek watershed approximately 12 miles south of Highway 299. I

Private L an d s 0 wnersh. IP In. t h e Eltapom C reekWt a ers hd e

Owner Township Range Section # acres Access road Surveyed I

Sierra Pacific 4N 6E 11 160 5N60 no

Sierra Pacific 4N 6E 2, 26 120 4N09 no I

McBride 4N 7E 30 160 4N09 yes Trinca Investment 4N 7E 28,29 340 4N09 yes I Lingemann 4N 6E 26 160 4N09 yes Rulofson 4N 6E 35 60 4N24B yes I I 4 I II)

Eltapom Creek Eltapom Creek Action Plan for

Private Lands Erosion Control Trinity River N

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I OBJECTIVES I The objectives of Phase I of the APPLE Eltapom project were: I 1) to make landowner contacts and seek permission to conduct field surveys, 2) to identify sediment sources on private lands,

I 3) to develop a priority list for treatment, and I 4) to prepare a report presenting the findings. The objective of Phase II was to implement erosion control treatments at the highest priority I sites identified in Phase I. Due to a lack of funding, only Phase I was implemented. A grant proposal to fund Phase II was submitted to the California Department of Fish and I Game (CDFG) in November, 1998 for consideration for funding under SB 271. I WATERSHED LAND USE Most of the Eltapom Creek watershed is part of the Shasta Trinity National Forest (United I States Department of Agriculture, Forest Service [USFS]) and is managed for public use, recreation, firewood gathering, and timber production. There are six private in-holdings, totaling approximately 1,000 acres, or 8% of the watershed. Three of the private holdings I are owned by private timber companies and three are owned by individuals or families. The Pacific Gas and Electric Company transmission line and its associated access road cross the I watershed. I ELTAPOM CREEK FISHERIES The most common species of anadromous fish present in Eltapom Creek is steelhead trout I (Oncorhynchus mykiss). Coho salmon (Oncorhynchus kisutch) were once present in Eltapom Creek but have disappeared in recent years (Pacific Watershed Associates 1994). Chinook I salmon (Oncorhynchus tshawytscha) are not known to utilize Eltapom Creek. According to California Department of Fish and Game data, (CDFG 1994), Eltapom Creek I had the most new redds (23) in the Hyampom Valley area and the most redds per kilometer (19.2) of all the tributaries in the South Fork Trinity River. Eltapom Creek was second to I Hayfork Creek among all South Fork Trinity River tributaries in total number of redds observed. Eltapom Creek (17) was second to the East Fork of the South Fork Trinity (22) in I I 7 I

1993 in terms of total number of steelhead redds and was first in terms of redds per I kilometer (13 .5 in Eltapom Creek vs. 5.8 for the second highest tributary - Butter Creek). The Coordinated Resources Management Plan for the South Fork Trinity River (Truman et. I al., November, 1996), states: "Eltapom Creek consistently has the highest density of juvenile steelhead within any tributary stream throughout the SFTR watershed." In 1994 I Eltapom Creek had a fish density of 0.920 fish per square meter, more than three times the density of the next highest South Fork tributary, Butter Creek, which had a density of 0.281 fi sh per square meter (Truman et al., 1996). I

Habitat typing surveys conducted in 1991 in the anadromous reach determined that the I most frequently occurring habitat types were step runs (33%), lateral scour bedrock pools (19%) , main channel pools (16%) , and low gradient riffles (14%) (Mayo 1992). Fine sediment I in spawning gravels was visually estimated at 17 to 20% and only 2% of the gravels were considered suitable for spawning. Researchers have fo und that fines in spawning gravel exceeding 20% cause egg mortality from suffocation and that emergence of fry is reduced I (McLeod 1995). The high percent of fines and lack of suitable spawning gravel run contrary to the high densities of redds and juvenile fish observed in Eltapom Creek. The timing of I the surveys in proximity to the 1987 fires may have resulted in estimates reflecting a short term increase in fines, or the visual estimates may overestimate the percent fines. I

A waterfall at mile 0.6 (cover photo & roll 8/98-1, photo 22, page A2 - 1) is a barrier to anadromous fish at low flow but at moderate winter flow, steelhead may be able to access I upstream reaches. However no fish surveys have been conducted and there are no data on the presence or absence of anadromous fish upstream of the waterfall. I

WATERSHED CHARACTERISTICS I

Hydrology: Eltapom Creek is a dendritic shaped watershed covering approximately 12,500 acres (-19.5 square miles). The elevation of the mouth is 1,312 feet and the highest point I in the watershed is 5,366 feet. The main stem length of Eltapom Creek is approximately 8.6 miles. Buckhorn Creek is the largest tributary at 5.0 miles in length. Allen Creek and I Clark Creek are the other significant tributaries, each being 3.5 miles long. The lower five miles of Eltapom Creek is a fourth order stream. The watershed includes 72 first order I streams totaling 31 miles in length. There are 17 second order streams comprising 17 miles I I 8 I I

I of stream and 3 third order streams totaling 5 miles. The stream density for the watershed is 2.97 miles of stream per square mile.

I The lowest 1.5 miles of Eltapom Creek runs through a steep gorge. The steep canyon walls and riparian vegetation provide shade and maintain relatively cool summer water I temperatures. In 1991 the maximum temperature observed was 65° and the average temperature was 62° over a 5 day monitoring period from August 1 through August 5 I (Pacific Watershed Associates 1994). The thermal properties of Eltapom Creek may attract fish from the main stem of the South Fork which would contribute to the high fish densities I observed in the lower channel. There are no precipitation gauges within the watershed so precipitation estimates must be I extrapolated from nearby gauges. Most gauges in the area were maintained for short periods and then discontinued. The nearest gauges include Hyampom (1948 - 1966), I Hayfork (1950 - 1979), and Big Bar (1982 - present). Annual precipitation averaged 44.73 at Hyampom, 36.45 inches at Hayfork, and 38.16 inches at Big Bar. These gauges are I located in the valley bottoms where precipitation amounts are lower than in the higher elevations of the surrounding mountains. The Eltapom watershed, ranging from 1,312 to 5,366 feet, probably experiences significantly more precipitation than any of these gauges. I In nearby Hayfork Creek, the upper watershed precipitation is 70 inches per year (USDA Forest Service 1998). The Eltapom Creek upper watershed probably experiences a similar I amount of precipitation. I Much of the precipitation in the upper watershed of Eltapom Creek (above 4,000 feet) comes in the form of snow from November through May. Frost heave and snow melt runoff are significant factors in the erosion processes at work in the upper watershed. The 2 year I recurrence interval for 24 hour precipitation totals at Hyampom is 3.4 7 inches and the 50 I year recurrence interval is 7.07 inches (Appendix I, Table 3, p.46). The stream gauging station closest to Eltapom Creek, USGS Gauge # 11528700, is on the I South Fork Trinity River approximately one-half mile down river from the mouth of Eltapom Creek. It began operation in 1966 and missed the most significant event of the past century, the 1964 flood . The USGS has estimated the 1964 flood to be 88,000 cfs. The I highest recorded flow in the South Fork Trinity, 75,000 cfs. occurred in 1986 (see Appendix I I, Table 4, p.47). I I 9 I

Flows in Eltapom Creek can be estimated by determining the discharge per square mile of I watershed for various flows measured at the South Fork gauge and applying them to the watershed area of Eltapom Creek. The bankfull flow (using a recurrence interval of 1.6 I years) for the South Fork Trinity River below Hyampom is estimated at 19,400 cubic feet per second (cfs). The watershed area upstream of the gauge is 764 square miles. The bankfull discharge per square mile of watershed is 25.4 cfs (Appendix I, Table 4, p. 4 7). Applying I this to the Eltapom watershed area of 19.5 square miles, the bankfull flow at the mouth of Eltapom Creek is estimated at 495 cfs. The 1986 flood in Eltapom Creek had an estimated I discharge of approximately 1,900 cfs. The 1964 flood in Eltapom Creek had an estimated discharge of approximately 2,250 cfs. The estimated average low flow for Eltapom Creek is I 1.23 cfs. and the estimated lowest flow (1977) was .36 cfs.

Vegetation: Eltapom Creek and its main tributaries generally run in a south-west to south I direction although the upper reaches of Eltapom Creek run east - west before turning southward downstream of the confluence with Allen Creek. The south facing slopes tend to I be hot and dry in the summer and vegetation on south facing slopes that have been burned or harvested tends to be dominated by Ceanothus (whitethorn, deer brush, snow brush), I manzanita, oaks, and chinquapin. The undisturbed areas are covered by a mixed conifer forest dominated by Douglas-fir and ponderosa pine, but which also include gray pine, I incense cedar, madrone, tan oak, live oak, white oak, and chinquapin. The western portion of the watershed has ultramafic (serpentine) soils associated with the Rattlesnake Terrane I and has sparse, specialized vegetation associated with this soil type.

Geology: The southwest portion of the Eltapom watershed is composed of metamorphic I rocks formed during the middle and late Jurassic period which are part of the Rattlesnake Creek Terrane. The eastern part of the watershed is primarily sedimentary in origin and I lies within the Hayfork Terrane. The Hayfork Terrane has a moderate instability and erosion hazard rating. A moderate rating is described as "Generally stable slopes and geologic aspect; occurs mostly in metavolcanic rocks of Hayfork Terrane; generally lower I precipitation than rest of basin; also includes valleys of Hayfork and Hyampom" (PWA

1994). I The south-western portion of the watershed has a high instability and erosion hazard I rating. A high rating is described as: "Moderately unstable slopes or erodible soils; abundant inactive and/ or ancient landsliding; less abundant active slides; road cut and fill failures, and moderate rilling and gullying; sheared and broken metamorphic rocks of I Rattlesnake Creek Terrane and landslide- prone parts of Hayfork Terrane" (PWA 1994). I 10 I I

I This area has ten active landslides and several ancient landslides. This is the steep, inner gorge area of the watershed. Landsliding is not currently a significant erosion process in the I upper watershed but the soft, sedimentary soils are highly susceptible to sheet and rill erosion.

I WATERSHED DISTURBANCES I The Eltapom watershed has an extensive network of roads in the eastern and south-eastern portions of the watershed while the northwest portion (east slope of Underwood Mountain) in the vicinity of Buckhorn Creek and Allen Creek is roadless except for the Sierra Pacific I property in Section 11, T4N,R6E. There are approximately 58 miles of roads in the watershed, not including skid trails on harvested areas. This equates to an average road I density of 3.0 linear miles of road per square mile of watershed. Excluding the USFS roadless area on the eastern slope of Underwood Mountain, the road density is 4 miles of I road per square mile of watershed. The total area of roads in the watershed is approximately 71 acres.

I When bare soil is exposed to precipitation, soil loosened by impact erosion is carried away with runoff (sheet erosion). As runoff is concentrated into draws by the slope of the ground I surface, the erosive power of the runoff increases, creating rills and gullies, which can turn into slumps, earth flows, and debris torrents. Areas of bare soil can lose from 0.1 inch to I over 1.0 inch of soil per year under such circumstances. On a 100 ft. section of dirt road that averages 10 feet in width, soil loss of 0.1 inch equates to 0.3 cubic yards. Soil loss of 1 inch I equates to 3 cubic yards of soil loss over 100 feet of road. The Eltapom watershed has experienced significant disturbance from wildfire and timber I harvesting. Air photo analysis reveals that approximately 3,800 acres of land have either been burned or been subjected to timber harvest activities. This equates to 30% of the I watershed. The Pacific Gas and Electric transmission line that parallels the 4N09 road has resulted in the clearing of approximately 50 acres of land (4.2 miles of transmission line at I an average width of 100 feet). During the summer of 1987 wildfires burned approximately 2,250 acres (18% of the I watershed) in the Eltapom watershed with fire intensity levels from low to extreme. Low intensity fires were typified by ground fires having slow rates-of-spread and low flame I heights. burning under the overstory forest canopy, consuming leaves, needles, and other ground litter. Extreme intensity level fires consumed all available ground fuels and spread I into the overstory forest canopy (Bill Clark, USFS fuels specialist, pers. comm.). Judy I 11 I

Jackson, a CDFG seasonal aid who conducted summer surveys in the South Fork Trinity I River, observed significant pool in-filling after the 1987 fires and a large alluvial fan formed at the mouth of the creek (Judy Jackson, pers. comm.). The alluvial fan was still present in I the summer of 1998 and the channel gradient from Eltapom Creek to the South Fork Trinity River created by the fan presents a barrier to coho and chinook salmon except maybe at high I flows (Bill Jong, CDFG, Arcata, pers. comm.). As of the summer of 1998, the alluvial fan was vegetated with willow and alder. I PROCEDURES I Prior to conducting field surveys, CDFG (Arcata and Weaverville) offices were contacted and telephone interviews were conducted with field personnel who had first hand knowledge of Eltapom Cr eek. An air photo review (1990 USFS air photos) was conducted to identify I landslides and other significant watershed features. Property ownership was researched at the Trinity County Assessor's office and landowners were contacted either by phone or in I writing. After access permission was obtained, field surveys were conducted. I Field surveys involved walking and driving the roads in the watershed, focusing detailed surveys on privately owned roads and the most severe erosion problems but also noting erosion problems that occurred on federally owned land (USFS). Culvert crossings were I examined and potential sediment production in case of failure was estimated. Estimates of sediment production from road surface erosion were made. Field surveys included photo I documentation of problem areas. I Findings are presented in the "RESULTS" section of this report. Cost estimates for treatment of erosion problems have been made and are included on page 32. Sites are prioritized for treatment based on actual and potential sediment production and likelihood I of delivery to a water course. I RESULTS Road Related Erosion Surveys I Sites have been assigned a priority for treatment. Priority 1 sites are the highest priority based on chronic sediment production or potential for failure with an accompanying large I volume of sediment production and a high likelihood of delivery to a stream. Priority 2 and I I 12 I I

I 3 sites are sites with chronic sediment production or potential for failure with an accompanying large volume of sediment production with a lower likelihood of delivery to a I stream because of the site location. Priority 4 sites should be treated during routine maintenance.

I Roads Accessing Private Lands I 4N09 Road (Power line Road), west of 5N60 The 4N09 has the most severe erosion of any of the roads in the Eltapom watershed, either I private or public. Therefore it received the most intensive survey.

Mile 0.00 to 0.35 - nine waterbars are constructed (photos 10, 13, roll 6/97-1; page A2 - 2). I The soil is sandy and highly erodible. This section of the 4N09 is estimated to lose an average of 1 inch of soil per year. Over this section of road (8 ft average width) that equates I to 39 cubic yards of soil loss per year. A spur road enters on the uphill side of the first waterbar. The spur road is 500 feet long and ends at the 5N60. It is water-barred every I 100 feet and has minimal sediment production.

Recommended Action - grade the road to outslope where feasible, re-grade the waterbars, I add 6 inch minus crushed rock to the road surface and to the waterbar outlets for energy I dissipation. Priority - 1

I Mile 0.35 - a perennial stream passes through a 24 inch diameter by 20 ft. long corrugated metal pipe (CMP); approximately 6 inches of fill overlays the pipe; the outlet has a 30 inch I drop to the stream channel. Potential soil loss is 7 cubic yards. Using the rational method (CDF 1983), a 52 inch diameter culvert is needed to withstand a 50 year runoff event.

I Recommended Action - calculate the needed culvert size using the slope-area method and I replace if undersized Priority- 1

I Mile 0.35 to 0.59 - seven waterbars are constructed (photo 11, roll 6/97-1; photo 14, roll 9/98-1, page A2 - 3; photo 12, roll 6/97-1; photo 15, roll 9/98-1, page A2 - 4). The soil I continues to be sandy and highly erodible. This section of road is estimated to lose an average of 1 inch of soil per year or approximately 31 cubic yards per year. I I 13 I

Recommended Action - grade the road to outslope where feasible, establish an inboard ditch I with outlets at waterbars where the road is severely entrenched, re-grade the waterbars, add 6 inch minus crushed rock to the road surface, inboard ditch, and to the waterbar I outlets for energy dissipation.

Priority - 1 I Mile 0.59 - access spur to McBride Property - this road is approximately 1/4 mile long I and is water barred every 100 feet. It is used infrequently and has minimal soil loss, estimated at approximately 3 cubic yards per year for the entire road. I Recommended Action - maintain waterbars

Priority - 4 I

Mile 0.59 to 0.77 - six waterbars are constructed (photo 14, roll 6/97-1; page A2-5). The I soil is still sandy and erodible but soil loss decreases slightly. This section of road is estimated to lose an average of 0. 75 inches of soil per year or approximately 18 cubic yards I per year.

Recommended Action - grade the road to outslope where feasible, re-grade the waterbars, I add 6 inch minus crushed rock to the road surface and to the waterbar outlets for energy dissipation. I Priority - 1 I Mile 0.77, Clark Creek - the creek is crossed by a bridge as well as a low water ford with one waterbar on the approach to the ford. Estimated soil loss from the ford approach is I approximately 1.3 cubic yards per year. A down log partially blocks the western approach to the bridge, encouraging vehicles to use the ford rather than the bridge. I Recommended Action - grade the approach to the ford and add 6 inch minus crushed rock. Remove the log that blocks the western approach to the bridge. I Priority - 1 I Mile 0.77 to 0.94 - seven waterbars are constructed. The soil continues to be sandy and highly erodible. This section of road is estimated to lose an average of 1 inch of soil per year I or approximately 22 cubic yards per year. I 14 I I

I Recommended Action - grade the road to outslope where feasible, re-grade the waterbars, add 6 inch minus crushed rock to the road surface and to the waterbar outlets for energy I dissipation. I Priority - 1 Mile 0.94 - a perennial stream passes through a 24 inch diameter by 20 ft. long CMP with I a crushed inlet and outlet; approximately 6 inches of fill overlays the pipe. Potential soil loss is 7 cubic yards. Using the rational method (CDF 1983), a 38 inch diameter culvert is I needed to withstand a 50 year runoff event. Recommended Action - calculate the needed culvert size using the slope-area method and I replace if undersized. I Priority - 1 Mile 0.94 - 1.14 - two waterbars are constructed; a ditch at mile 1.13 is turning into a gully I (photos 15 & 16, roll 6/97-1; pages A2 - 1,2). The gully is 4 ft. wide at the top and 4 ft. deep, and at 5 feet grows to 8 ft. wide by 6 feet deep, continuing for 25 feet. The total I estimated sediment production from the ditch is approximately 30 cubic yards. The road is soft and rutted through a depression at mile 0.95 (photo 16, roll 9/98-1; page A2 - 5); I estimated sediment production from the road is 31 cubic yards per year. Recommended Action - re-grade the waterbars, add 6 inch minus crushed rock to the road I surface and to the waterbar outlets for energy dissipation. Rock line the gully with one to two foot diameter rock and create three check dams.

I Priority - 1 I Mile 1.14 - A 12 inch diameter culvert drains a depression on the north side of the road. I Recommended Action - none. Mile 1.14 - 1.27 - one waterbar is constructed; estimated sediment production is 0.1 inch I per year or - 2 cubic yards per year for this section of road. I Recommended Action - grade and add 6 inch minus crushed rock to the road surface. Prioritv - 1 I I 15 I

Mile 1.27 - A perennial stream passes through a 36 inch diameter CMP with half the flow I (at summer flow) passing beneath the pipe. The pipe is in good shape with little rust. Rotting logs lie in the channel upstream of the inlet and could potentially block the inlet if I mobilized by high flow. Potential soil loss is 10 cubic yards. Using the rational method (CDF 1983), a 60 inch diameter culvert is needed to withstand a 50 year runoff event. I Recommended Action - calculate the needed culvert size using the slope-area method and replace if undersized. I Prioritv - 1 I Mile 1.27 - 1.65 - The road condition has improved with three waterbars constructed and some rock on the road surface; the surrounding terrain is rockier; an inboard ditch I occasionally encroaches into the road. Estimated sediment production is 0.5 inch per year or 24 cubic yards per year for this section of road. I

Recommended Action - From mile 1.52 to 1.56, outslope the road and add 6 inch minus crushed rock to the road surface and to the waterbar outlets for energy dissipation. Re-dig I and rock line the ditch, filling in the portions encroaching into the road and add 1 ft. diameter rock for check dams every 25 feet. I Priority - 1 I Mile 1.65 - A bridge crosses Eltapom Creek with an unnamed and unmapped spur road entering on the upstream side of the bridge from the north side of the road (see 4N09/ Mi. I 1.65 spur rd. survey notes).

Mile 1.65 - 1.85 - Three waterbars are constructed with a section of inboard ditch leading to I the second waterbar; the third waterbar is at an 18 inch by 40 ft. CMP with a drop inlet. Runoff overflows the culvert inlet, creating a gully through the outboard fill slope; the culvert I has a "shotgun" outlet (i.e., culvert is not set to grade and has no down spout or energy dissipation mat; runoff "blasts" from outlet, causing downslope erosion). The tributary I upstream of the road discharges a significant amount of sediment (hence the drop inlet). Potential sediment production is 60 cubic yards. Road surface erosion is producing I approximately 12 cubic yards of sediment per year over this section of road.

Recommended Action - Remove the culvert and replace it with a rock lined swale; construct a I sediment retention basin on the uphill side of the road by excavating a V shaped depression I 16 I I

I 3 ft. deep (maximum) by 10 ft. wide by 6 ft. long and create a rock check dam across the outlet of the basin, with the low point of the V matching the low point of the swale.

I Priority - 2

I Mile 1.85 - 2.20 - the road condition is o.k ., with minor rilling that could be eliminated by installing waterbars (4 total) at approximately 500 ft. intervals. Estimated sediment I production is approximately 4.5 cubic yards per year from this section of road. Recommended Action - regrade and install 4 waterbars, add 6 inch minus crushed rock to I the road surface and to the waterbar outlets for energy dissipation. I Priority- 3 Mile 2.20 - an 18" by 30 ft. CMP draining a swale crosses the road. Using the rational I method (CDF 1983), a 16 inch diameter culvert is needed to withstand a 50 year runoff event. Potential sediment production is 8 cubic yards.

I Recommended Action - none, the existing pipe is adequate. I Mile 2.20 - 2.4 7 - the road crosses a swale at mile 2.27 and there is minor rilling on the road at mile 2.47. Estimated sediment production is approximately 3.4 cubic yards per I year. Recommended Action - grade the road and add 6 inch minus crushed rock to the road I surface. ·1 Priority- 3 Mile 2.47 - an 18" by 30 ft. CMP crosses the road. Using the rational method (CDF 1983), I a 15 inch diameter culvert is needed to withstand a 50 year runoff event. Potential sediment production is 6 cubic yards.

I Recommended Action - none, the existing pipe is adequate

Mile 2.47 - 2.55 - the road is in good condition with minor sediment production, estimated I at 1 cubic yard per year.

I Recommended Action - regular road maintenance. I Priority- 4 I 17 I

Mile 2.55 - a spur road leaves the 4N09 and heads northeast toward the power line, I continuing down into the forest , ending in a grassy meadow. No problems currently exist but if this road is used during wet weather there is potential for damage to the meadow and I potential sediment input to the creek.

Recommended Action - install a "tank trap" (a deep trench across the road which will block I vehicular access) under the power line to prevent use of road.

Priority - 3 I

Mile 2.55 - 2. 72 - one waterbar on the road is losing soil; estimated sediment production is I 2.2 cubic yards per year; a spur road with minimal sediment production heads uphill on the south side of the road to the power line. I Recommended Action - re-grade the waterbar and add 20 cubic yards of 6 inch minus crushed rock. I Priority - 3 I Mile 2.72 - 2.97 - minor rilling from mile 2.82 to 2.87, discharging at a waterbar at mile 2.87; estimated sediment production is 3.1 cubic yards per year. I Recommended Action - grade the road and add 6 inch minus crushed rock. I Priority - 3

Mile 2.97 - a 12" diameter CMP is totally plugged but appears unnecessary I

Mile 2.97 - 3.03 - the road is o.k.; estimated sediment production is .75 cubic yards per I year; an 18" CMP at mile 3.03 has a small sediment plug at the inlet but the pipe has less than 6" fill over it; potential sediment production is 2.5 cubic yards. Using the rational I method (CDF 1983), a 14 inch diameter culvert is needed to withstand a 50 year runoff event,. i.e. the current pipe is adequate. I Recommended Action - clean the inlet

Priority - 1 I

Mile 3.03 - 3.28 - the road is o.k.; estimated sediment production is 3 cubic yards per year; I an 18" CMP at mile 3.28 has a partially (1/3) clogged inlet; the CMP has - 6 inches of fill I 18 I I

I over it and a 6 ft. drop at the outlet; potential sediment production is approximately 20 cubic yards. Using the rational method (CDF 1983), a 16 inch diameter culvert is needed to I withstand a 50 year runoff event, i.e., the current pipe is adequate.

Recommended Action - clean the inlet and place 6 cubic yards of 1-3 ft. diameter rock for I energy dissipation at the outlet. I Priority - 1 Mile 3.28 - 3.43 - the road is o.k.; estimated sediment production is 1.9 cubic yards per I year; a 30" CMP (by 30 ft. long) at mile 3.43 has a shotgun outlet with a 6 ft. drop. and the fill slope is head cutting around the pipe. Potential sediment production is 45 cubic yards. I Using the rational method (CDF 1983), a 27 inch diameter culvert is needed to withstand a 50 year runoff event, i.e., the curr ent pipe is adequate. An old 18" pipe is plugged and I buried 3 feet below and off to the side of the current pipe. Recommended Action - place 10 cubic yards of 1-3 ft. diameter rock for energy dissipation at I the outlet and up into the eroding fill slope around the outlet. I Priority - 1 Mile 3.48 - 5.13, Junction of Roads 4N09 and 4N24 - the road from mile 3.48 to mile I 5.13 is well rocked and maintained; estimated sediment production is 6.5 cubic yards per year.

I Mile 3.88 - a tributary crosses through a 30" by 30 ft. CMP; the top of the outlet is 4 ft. below the road and the bottom of the channel is another 4 ft. below the outlet (i.e., shotgun I outlet). Potential sediment production is 40 cubic yards. Using the rational method (CDF 1983), a 28 inch diameter culvert is needed to withstand a 50 year runoff event,. i.e. the I current pipe is adequate.

Recommended Action - place 10 cubic yards of 1-3 ft. diameter rock for energy dissipation at I the outlet. I Prioritv - 1 I Mile 4.08 - Eltapom Creek - bridge crossing. Mile 4.38 - intersection of 4N09 and Skunk Ranch Road. I I 19 I

Mile 4.63 - Buckhorn Creek crossing (low water ford). I

Mile 5.07 - watershed divide. I Mile 5.13 - Junction of 4N09 and 4N34 (out of Eltapom Creek watershed). I 4N09 Road (Power line Road), east of 5N60

The 4N09 east of the 5N60 is gated and the survey was conducted by walking. Station I 0+000 is at the culvert inlet on the south side of the junction of the 4N09 and the 5N60. The gat e is at 0+126. I

Summary - This road is similar to the power line road west of the 5N60. It is built in erodible so ils with little or no rock surfacing. Waterbars were installed but many of them I require maintenance. Because of the erodible nature of the underlying soil, the waterbars should be re-excavated. Crushed rock (6 inch minus) should be used to line the waterbars I and create energy dissipation mats at their outlets. I The power line is accessed by spur roads at 1+290 and 3+060 and by the 4N49 road at 5+480. The power line access roads have the most severe erosion, having lost a total of approximately 220 cubic yards of soil and losing an estimated 10 cubic yards of soil per I year. Most of the waterbars are no longer functioning and need to be re-built. A total of 10 rock lined waterbars should be installed on these roads. I On the 4N09 road, soil loss is estimated at 44 cubic yards per year. Approximately 17 rock I lined waterbars (14 on USFS and 3 on Trinco.) and 3 rock lined swales (2 on USFS and 1 on Trinco.) should be constructed. Six inch minus crushed rock should be used to line the waterbars/ swales and to construct energy dissipation mats at their outlets. I

Details - 4N09 and power line spur roads I 0+000 to 0+126 - an 18 inch CMP passes under the 5N60. Small diameter woody debris above the inlet could plug it. Ruts from the 4N09 road drain to the inlet. The road is gated I at 0+126. I Recommended Action - clean the inlet and install a trash rack.

Prioritv - 2 I I 20 I I

I 0+126 to 0+620 - an inboard ditch spills across the road at 0+490 and creates a rut (photos 1-6, roll 10/98-1; pages A2 - 6,7) that runs down to the 5N60 Rd. culvert (0+000). I Estimated soil loss is 30 cubic yards.

Recommended Action - re-grade; clean the inboard ditch; install waterbars every 100 feet; I add 6" minus crushed rock to the road. I Priority - 2 0+620 - a draw crosses the 4N09 road; runoff has created a rut 50 ft. long by 1.5 ft. wide by I 0.5 ft. deep. Estimated soil loss is 1.3 cubic yards.

Recommended Action - grade the road and create a rock lined swale; add 6" minus crushed I rock to the road.

I Prioritv - 2

0+620 to 0+815 - estimated soil loss is 4 cubic yards; a draw crosses the road at 0+815; an I inboard ditch captures half the runoff from the draw and discharges it at 0+620.

I Recommended Action - grade the road and create a rock lined swale at 0+815; add 6" minus crushed rock to the road.

I Priority - 2

I 0+815 to 1+290 - the road makes a hairpin turn around a ridge at - 1+200; a spur road to the power line intersects the 4N09 road at 1+270; an inboard ditch crosses the road at 1+290 (above the hairpin turn) and continues as an inboard ditch below the turn, crossing I the road and creating a rill at 1+170; estimated soil loss is - 5 cubic yards.

I Recommended Action - install a waterbar at 1+290 (uphill of the power line spur), directing it to the north; grade the 4N09 road, installing waterbars approximately every 100 feet (at I 0+920, 1+020, 1+ 120); add 6" minus crushed rock to the road. I Priority - 2 I I I 21 I

1+270 Power line spur road: I

0+000 to 0+300 - from 0+000 to 0+100 there is minor soil loss (0.7 cubic yards); from 0+100 to 0+300, the slope is 30%, with two ruts running down the road; at 0+300 the slope I changes to 10%; old waterbars are being bypassed; estimated soil loss is 14 cubic yards. I Recommended Action -install rock lined waterbars (w/ 6" minus crushed rock) every 100 feet.

Prioritv - 2 I 0+300 to 0+880 - two large ruts run down the road, averaging 1 ft. wide by 3 inches deep I (photos 10, 11, 12, roll 10/98-1; page A2 - 8); the ruts discharge at 0+380 and 0+425; old waterbars are by-passed at 0+482, 0+557, and 0+707; the spur road levels out at O+ 780; I estimated soil loss is 34 cubic yards.

Recommended Action -install rock lined waterbars (w/ 6" minus crushed rock) every 100 feet. I Priority - 2 I 0+880 - the spur road ends at a deep draw. I 4N09 (continued)

1+290 to 1+770 - small ruts are forming; estimated soil loss is 3.5 cubic yards. I Recommended Action - install rock lined waterbars (w/ 6" minus crushed rock) every 300 I feet.

Priority - 2 I

1+770 to 3+060 - the road is o.k. with only minor soil loss (photos 17, 18, roll 10/98-1; page A2 - 9); estimated soil loss is 4 cubic yards. I Recommended Action - regular maintenance. I Priority - 4 I 3+060 - power line spur road - a 300 ft. long spur road with 2 parallel ruts down it ends at the power line (photos 13, 14, roll 10/98-1 ; pages A2 - 8,9); estimated soil loss is 6 cubic I yards. I 22 I I

I 3+060 - power line spur road - a 300 ft. long spur road with 2 parallel ruts down it ends at the power line (photos 13, 14, roll 10/98-1; pages A2 - 8,9); estimated soil loss is 6 cubic I yards. Recommended Action - install rock lined waterbars (w/ 6" minus crushed rock) at 0+020 and I 0+150 feet. I Prioritv - 2 I 3+060 to 3+360 - estimated soil loss is - 1 cubic yard. 3+100 - property boundary between USFS and Trinco Investment Company.

I 3+360 - a corrugated metal berm drain is non-functional because the soil beneath it has eroded and allowed the water to pass underneath (photos 15, 16, roll 10/98-1; page A2 - I 11).

Recommended Action - install a rock lined waterbar and re-install the berm drain at the I waterbar outlet; excavate a 1 ft. deep by 3 ft. wide trench and fill it with 6 inch minus I crushed rock where the waterbar fe eds into the berm drain. Priority - 2

I 3+360 to 3+530 - estimated soil loss is 1.3 cubic yards. I 3+530 - a draw feeds a 12" X 30' CMP; the inlet is - 1/4 plugged; a rut discharges over the outlet; soil loss from the rut is approximately 2 cubic yards.

I Recommended Action - remove the culvert and construct a rock lined swale. I Priority - 2 3+530 to 4+100 - estimated soil loss is 3 cubic yards from 3+530 to 3+730; an inboard I ditch which starts at 4+100 flows onto the road, creating a rut which discharges at 3+730. I Recommended Action - install a rock lined waterbar at 4+100. Prioritv - 2

I 4+100 to 5+480 - estimated soil loss is 7 cubic yards; a spur road heading downhill to the I south (Trinco A Rd. ) intersects the 4N09 Rd. at 4+160; the 4N49 intersects the 4N09 at 5+ I 23 I

300; from 5+300 to 5+400 a rut is forming and discharges to the south side of the road at I 5+300. I Recommended Action - install a rock lined waterbar at 5+400.

Priority - 2 I 5+ 480 to 7 + 210 - estimated soil loss is 5 cubic yards. I Sierra Pacific Roads

The Sierra Pacific Company was contacted but did not grant access permission to conduct I surveys on their property. They own two parcels in the watershed - one parcel of approximately 160 acres in the northwest corner of the watershed in the Buckhorn Creek I sub-watershed and another parcel of 120 acres adjacent to the Skunk Ranch in the lower Buckhorn Creek sub-watershed. I Trinco Investment Company Roads I There are two primary roads through Trinco Investment Company land. The roads parallel the two headwaters tributaries in sections 28 and 29, T5N, R7E, . The northern road I (Trinco A) is approximately 2 miles long. It intersects the 4N09 road approximately 1/4 mile west of the junction of the 4N49 and 4N09. The intersection of the Trinco A road and the I 4N09 is 0+000.

Trinco A road I 0+000 to 2+600- the road crosses an Eltapom Creek headwater tributary at 1+160. A I second headwater tributary is crossed at 2+600. From 0+000 to 2+600 there are no significant erosion problems. I 2+600 to 5+300 - the road runs downhill from 2+600 to 3+500 with runoff creating rills which have lost approximately 20 cubic yards of soil over 900 feet. Old waterbars are no I longer functioning and are being bypassed, creating the rills. Minor rilling continues from 3+500 to 5+300. Soil loss is estimated at 10 cubic yards. I Recommended Action - re-establish and maintain waterbars. I Prioritv - 3 I 24 I I

I Recommended Action - maintain waterbars I Priority - NA/ routine maintenance 7+100 to 10+500 - the road is built in the creek bed from 7+100 to 8+500 and from 9+000 I to 9+600; winter flows are eroding the soil placed in the draw to create the road; soil loss is estimated at 40 cubic yards from 7+100 to 7+700, 120 cubic yards from 7+700 to 8+500, I and 14 cubic yards from 8+500 to 9+200; total soil loss = 174 cubic yards. The road continues northeast and has no significant erosion past 9+200.

I Recommended Action - obliterate the road and restore to natural contours from 7+100 to 9+600

I Priority -2

I 10+500 - watershed divide. I Trinco B road The Trinco Broad intersects the 5N60 road in the southwest quarter of Section 29. The B I road is approximately 0.4 miles long and for most of its length is on the north side of the main stem of Eltapom Creek. It runs east for approximately 0.35 miles and then crosses I Eltapom Creek at a "Humboldt" crossing (logs laid in the stream with soil placed over them), turning south at the crossing. The B road intersects with the A road approximately 200 feet south of the Humboldt crossing. The Humboldt crossing diverts some of the flow out of the I creek channel at high flow and diverts it down the B road for approximately 150 feet, I creating a rill that has lost approximately 5 cubic yards of soil. Recommended Action -remove the Humboldt crossing and re-establish the natural channel; I install 2 waterbars west of the crossing, one at 50 ft. and one at 150 ft. I Priority- 2 Skunk Ranch Road

I The main access road has no significant erosion problems. A spur road on the west side of Buckhorn Creek has a 300 ft. section on a hill that is rutting and losing approximately 3 I cubic yards of soil per year. I I 25 I

Recommended Action I Install 3 waterbars on the west side spur road. I Priority - 4 I USFSRoads I 4N09/ Mi. 1.65 Spur Rd. I This road connects the 4N09 road to the end of the 4N25C road. With 0+000 at the 4N09 road, at O+ 800 feet a draw crosses the road and the road forks with one fork continuing uphill to the 4N25C road and the other following the draw to a hunter's camp on the terrace I adjacent to Eltapom Creek. Runoff is captured by the spur road and is creating a gully which continues for approximately 300 feet, ending on the right bank terrace of Eltapom I Creek. The gully has lost approximately 40 cubic yards of soil but it has been deposited on the terrace and has not been delivered to the creek. I Recommended Action I The spur road should be closed to traffic and the spur road to the hunter's camp should be restored to its natural contours. I Priority- 4 I 4Nll

The 4Nll road is approximately 2.8 miles long, running east - west in the upper watershed I on the south side of Chaparral Mountain. Ditch relief culverts at mile 0.1, 0.19, and 0.38 miles from the 4Nll/ 4N41 junction (mis-labeled 4N14 on the USGS map) are partially I clogged. No significant erosion problems were observed.

Recommended Action - clean the inlets. I

Priority- 4 I 4N11G I I 26 I I

I The 4N11G road is 1.25 miles long, parallel to and upslope of the 4Nll road, just below the summit of Chaparral Mountain. The outboard side of the road has five sink holes in the fill I approximately 0.3 miles from the 4Nll road, indicating water piping through the fill and creating the potential for fill failure. The fill slope is steep and prone to failure in this area. I Otherwise this road has no significant erosion problems. Recommended Action - repair the holes in the fill to prevent saturation and fill failure

I Priority- 4

I 4N24

The 4N24 road is the main access road to Wigdon Place and the Skunk Ranch when coming I from Hyampom. Approximately 2.8 miles are within the Eltapom watershed. It has a slump 4.1 miles from the 5N60 road which has dropped approximately 1.5 to 2.0 feet. This I road is maintained by the Forest Service and other than the slump has no significant erosion problems.

I Recommended Action - investigate cause of slump and correct if feasible

I Priority- 4 I 4N24B The 4N24B road accesses Wigdon Place and is approximately 0.5 miles long. It has no I significant erosion problems. I Recommended Action - none 4N25

I An un-named spur road 1.45 miles south of the junction of 4N25 and 5N60 (near the northeast corner of section 19, R7E,T4N) heads uphill. A waterbar 50 feet up the road feeds I into a draw and into an 18" culvert under the 4N25 road. The inlet of the culvert is 75% plugged (photo 23, roll 10/98-1; page Ail-10).

I Recommended Action - remove the soil from the culvert inlet and install a drop inlet to prevent the inlet from re-plugging in the future. Calculate the size of culvert needed to I withstand a 50 year storm and replace the culvert if the calculations show it is undersized. I Re-build the waterbar at the bottom of the road (photos 24, 25, roll 10/98-1; page AII-10) . I 27 I

Priority - 1 I 4N25B I The 4N25B road is approximately 0.35 miles long and is in the Allen Creek sub-watershed. It has no significant erosion problems. I 4N25C I The 4N25C road is approximately 1.3 miles long. It leaves the 4N25 road on the ridge between Allen Creek and Eltapom Creek and descends into Eltapom Creek, connecting with I an unmapped road that intersects the 4N09 road at mile 1.65. It has no significant erosion problems. I 4N25D

The 4N25D road is approximately 0.45 miles long on the east side of Allen Creek in the I upper watershed. It is overgrown with snow brush and deer brush. It has two 18" CMP's with inlets that need cleaning but otherwise has no significant erosion problems. I

4N25E I The 4N25E road is closed to vehicles although motorcycles have been using it and damaging waterbars. The road is in good condition, rocked, and water-barred with no significant I erosion problems. Some of the waterbars are by-passed because of motorcycle created ruts and should be re-excavated. I 4N27 I The 4N27 road is approximately 1.3 miles long. Five culverts were examined. All are corrugated metal pipes, set to grade, and in good condition. The lower five have deeply set I outlets with large volumes of fill and high potential sediment yields if they fail. Culvert sizes were not calculated under this project. Rust lines on the pipes vary from 20% to 35% of the pipe capacity. The rule of thumb is that a rust line at one third or less of the pipe I capacity indicates an adequately sized pipe. I I I 28 I I I The culverts are summarized below: (0 is the junction of 4N25 & 4N27; 1+000= 1,000 ft.) Location Size Notes I 1+ 000 ft. 40 ft. x 18" 3.5 ft. of fill over the outlet 1+ 200 ft. 60 ft. x 18" 20 ft. of fill over the outlet; a dead 6 I inch diameter tree at the inlet along with sticks and branches could plug I the inlet. 1+ 500 ft. 60 ft. x 18" 20 ft. of fill over the outlet I 3+ 000 ft. 40 ft. x 24" on a perennial stream 4+ 800 ft. 60 ft. x 18" 16 ft. of fill over the outlet.

I Corrugated metal berm drains, waterbars, and dips are effectively used to prevent erosion of the outboard fill on the 4N27 road. The road ends at a landing at - 1.3 miles.

I 4N27A

I The 4N27 A road is approximately one-half mile long. One culvert was observed at - 1,100 ft. It was 18" X 60 ft. with 12 ft. of fill over the outlet and 3 ft. of fill over the inlet. The I road was in good condition with minimal sediment production. I 4N34 The 4N34 is on the west side of the Skunk Ranch near the western divide of the Eltapom watershed. The 4N34 is accessed from the 4N09 road. A slump on the road at mile 0.15 is I in the Buckeye Creek watershed. Only 0.3. miles are in the Eltapom watershed.

I 4N34A

The 4N34A road accesses the power line from the 4N34. The first 200 feet of road is steep I and deeply rutted. Estimated sediment production is 10 cubic yards. I Recommended Action - install rock lined waterbars every 50 feet or de-commission I Priority - 2 I I I 29 I I 4N41

The 4N41 road is mis-labeled "4N14" on the USGS map. It is a connecting road between I the 5N60 and 4Nll and parallels the upper reaches of Clark Creek. It does not have any significant erosion problems. I 4N41A I The 4N41A road is blocked by down trees and debris approximately 0.5 miles from the 4N41 road. It has no significant erosion problems. I 4N43,4N43A,4N43B I These roads total approximately 1.45 miles. They generally follow a ridge in the upper watershed between Buckhorn and Allen Creeks and access timber harvest units. They have no significant erosion problems. I

4N47 I

The 4N4 7 is the paved road that connects the 5N60 Road to the Big Bar - Hayfork Road. Only 0.1 miles lies within the Eltapom watershed. It has no significant erosion problems. I

4N49 I The 4N49 is an upper watershed road on the west side of Hyampom Mountain. The north half of the road is in the Clark Creek sub-watershed and the south half is in the main stem I Eltapom watershed. Starting with 0+000 at the north end of the road at the 5N60/ 4N49 junction: I

0+000 to 0+800 - the ground is soft (no rock on road) with minor soil loss (approximately 5 cubic yards total soil loss for this section of road). I Recommended Action - grade and add rock to the road if it is to be used I Priority - 4 I 0+800 to 8 + 400 - the road has no significant erosion problems

8 + 400 - a draw which is the headwaters of a tributary in Section 20; R7E,T4N crosses the I road and feeds into a berm drain which discharges below the 4N49 road. Uphill of the I 30 I I

I 4N49 a skid road is located in the draw. The skid road is steep (45% on the lower 200 ft., 20% from 200 to 400 ft., then levels out) with deep rills. Sediment production is estimated I at 20 cubic yards. I Recommended Action - decommission the skid road and re-vegetate. Prioritv - 3

I 8 + 400 to 11+000 - a 3.5 ft. diameter log blocks the 4N49 road at 8+500. A trench blocks the road at 9+500, just north of the PG&E power line. This is the property boundary I between USFS and Trinco Investment Company. I 5N09 The 5N09 has approximately one mile of road in the Eltapom watershed. It is near the I northern watershed divide and has no significant erosion problems. I 5N60 The 5N60 road is the main access road between Burnt Ranch and Hyampom and is paved I for most of its length through the Eltapom watershed. It has no significant erosion problems.

I 5N60G I The 5N60G road extends approximately 1,000 feet uphill from the 5N60 road and ends at a timber harvest unit with numerous skid trails heading up into the forest. The lower 300 I feet of the road is steep with no road rock but is adequately water-barred. 5N60H I The 5N60H road is a short spur road (0.25 miles) heading north from the 5N60 road and parallel to an unnamed perennial stream. It is water-barred every 100 to 200 feet and re­ I vegetating naturally. It is stable with no erosion problems. I I I I 31 COST ESTIMATES and PRIORITY LIST I

Vehicle Materials Site Cumulative Priority Backhoe Bulldozer Dumo Loader Water Labor Site V subtotal Cost I truck truck

4N09W; mi. 0 to 0.35 rd. $2,400 $7,644 $2,940 $1,200 $2,080 $152 $1,050 $17,466 $17,466 1 4N09W; mi. 0.35 pioe $270 $3 12 $23 $914 $1,519 $18,984 1 4N09W; mi. 0.35 to 0.59 $1,560 $5,242 $2,016 $780 $1,352 $99 $910 $11,958 $30,942 1 4N09W; mi. 0.59 to 0.77 $1,680 $3,931 $1,512 $840 $1,456 $106 $700 $10,225 $41,168 1 I 4N09W; mi. 0.77 $120 $180 $104 $8 $105 $517 $41,684 1 4N09W; mi. 0.77 to 0.94 $1,200 $3,713 $1,428 $600 $1,040 $76 $665 $8,722 $50,406 1 4N09W; mi. 0.94 pipe $270 $312 $23 $655 $1,260 $51,666 1 4N09W; mi. 0.94 to 1.14 $1,440 $4,368 $1,680 $720 $1,248 $91 $770 $10,317 $61,983 1 4N09W; mi. 1.14 to 1.27 $546 $2,184 $840 $273 $473 $25 $336 $4,677 $66,659 l I 4N09W; mi. 1.27 pipe $360 $160 $12 $934 $1,466 $68,125 l 4N09W; mi. 1.27 to 1.65 $2,520 c- $8,299 $3,192_ ~ . _$::..1:.c,2::.:6:0:+-...:$:.::l-"',7c:'6~4+--"'$1°"2"'9_t--$=-1'-'-'8"'6::2:..+--$=-1:::9'-",0C:2"'6+--.::C$8::,70-'-,1~50-'1'-171----1 c4~N~0:.::9~W~;~m~i.'...C3~.0~3~c~le~a~n~i~n~le.::t -1--~~+-----+----~-c--t--~~+-----+--~~$.::40"'-+-----"'$~3-+---~-l--~~$~4=-3-l----'$""8:c7~,1:;:9~4__J_"__l ~~ 1 4N09W; mi. 3.28 E.D. mat $360 >---- $156 $60 __ $160 $12 $35 $783 $87,977 1 4N09W; mi. 3.43 E.D. mat $360_ '-- _ --7$1=5~6-+-- ~ _ 1-----'$::l:.::6c:.0 __1 _ __.:$::c1:::2c+- $35 ___:;:_ $7'--'8'-"3--1-----""$8::8"-',7"'5"-9-Ll I 4N09W; mi. 3.88 E.D. mat --+- $360 c- $156 _ _ $60 $160 $12 $35 $783 $89,542 , 1_ 4!'<25 R_d .• mi. l.45~ MP $180 t \ - $160 ::- $12~ $100 $452 $89.994 _l 1 $791 59.106 ! $89,994 ' $2,160 l, $11.466 $35,849 $13.968 $5,673 i Priority 1 sub~a_ls i l -1 1 $350 i M,557 I 4N09W: m1. 1.85 swalc $960 Si.560 $600 $400 SG 40 $47 $455 ; $4,798 i 4N09E; 0+000 to 0+620 $720 $2.028 $780 , $300 . $480 $35 S_!_4o I $1,516 4N09E; 0+620 to 0+815 l $240 S624 · $240 I $100 $160 · $12 i $3,789 $104,653 2 4No9E; 0+815 to 1+290 S§Q9 _: Sl.560 -$600 1· s2so $400-- $29 ' 1- $3,789 $108,442 2 4N09E: 1+290 to 1+710 + $600 Sl ,560 ·- $600 $250 S400 $29 L ~ s35 $677 $109,119 '2 I 4N09E; 3+360 berm drain s2.lo ' $156 I $60 I $100 $80. S6 $70 $1,014 $110,133 2 4N09E; 3+530 swale _ S24Q 1· $312 . SlZO- $lo0 $160 . s_!]J__ $1,014 $111.147 2 4N09E; 4+100 swale $240 $312 $120 - SloO - $160 $I:n· --s70 l - ~ $70 $1,014 $112,160 12 4N09E: 5+400 swale $~ 1 $312 $120 ~ _____.: $~1_60"-__$~ 1=2_, $105 $2.288 $114,448 2 1~7_QE.ls; 0 to 0+360 L j $720 $468 7$180 $300 $480 I $35 - $210 $119,024 2 1+270ols; 0+300 to 0+880 - s1"-,4"'4'-"o-t----Os"°9°"35=-+-- $3='6~0'--J-----'$'"6"°o~o+--~$.;:96~0+--.:::$'==7o $4,576 I $140 $2,027 $121,052 2 3~+:..:0"'6"-0n"'l"'s;"'°O:..ctc:o ...:O_.c+ ::..30"'0'-c---+- _ ~ $480 $624 $240 $200 $320 $23 $9,746 $130,797 2 Tr.A; 7+100 to 10+500 $3,000 $624 $240 $1,250 $4,000 $292 $340 $140 $2,411 $133,208 2 Tr.B; Humboldt crossin" $720 $624 $240 $640 $47 $210 $2,571 $135,778 2 1 ~4~N~3~4A~------~--f-----'$~6~00-'-+ __$~ 9~3~6 -+------"'$3~6~0 -t----"$2=5~0-t-----'=-$=20=0-+-_~$1=5~ I Prioritv 2 subtotals -~$~7=20~~-~$1=0~,3~2~0 -+---"$=12~,6=3~6-l--~$42,8::..6=0:....i--~~$~4,~30=0:..+-~$~9~,2~40=-+__,$~6~74.:.._ 1 __$3 ~,0~3~5 --1------"$~45~,7~8~5-l------1-~~-- I 4N09W; mi. 1.85 to 2.20 $2,400 $7,644 $2,940 $1,000 $3, 120 $228 $1,715 $19,047 $154,825 3 4N09W; mi. 2.20 to 2.47 $1,800 $5,897 $2,268 $750 $1,200 $88 $1,323 $13,325 $168,150 3 4N09W; mi. 2.55 spur _ $120 $120 $50 $80 $6 $376 $168,526 3 I 4N09W; mi. 2.55 to 2.72 $120 $312 $120 $50 $80 $6 $70 $758 $169,284 3 J.-'."-1 ~4~N~0~9W.'.'...!_;~m~i:..=.-""'=:.==.c.~2~.7~2~t~o~2~.9~7co...=-'-'-=--1----l----l---- $~1~,6~8~0'--i--~S:,:4~,3"'678+--7$1~,~68~0"4-----'$~7~0~0+--~$.;:1,~l~20::.+~~$~872+----'$~9~8"'0+----'$~1~0~,6~1 ~0+--7$~17~9"',8~9~4-t-3-- - - Tr.A; 2+600 to 5+300 $2,160 $2,808 $1,080 $900 $1,440 $105 $630 $9,123 $189,017 3 4N49; 8+<1()0 -· __ $600 $250 $200 $19 $50 $1,119 $190,136 3 I $3,700 $7,240 $533 $4,768 $54,358 I $21,029 $8,208 Prioritv 3 subtotals $0 $8,880 $69,514 $27.036 $13 673 $27 461 $1997 $16,909 $190,136 Prioritv 1+2+3 totals $2.880 $30 666 I I I I I I I 32 I I

I RECOMMENDATIONS

One of the recommendations made by the California Department of Fish and Game is to I "Maintain naturally spawning steelhead populations by protecting the remaining prime stream habitat and the watershed... Protection is the key factor because the degradation of I stream habitat due to poor land-use practices has not been overcome by previous efforts. Damage to stream and watershed do not lend themselves to quick fixes." (California I Department of Fish and Game 1994, pp. 251, 252 ) The best way to protect the habitat is to reduce sediment input from management activities. Sediment input is primarily from I non-point sources associated with erosion of road surfaces. The rate of sediment production from the worst section of the 4N09 (mile 0.0 to 1.6 west of I the 5N60 Rd.) is approximately 110 tons of sediment per square mile. The U.S. Environmental Protection Agency has proposed total maximum daily loading (TMDL) for I sediment production in the South Fork Trinity River watershed (U.S.E.P.A. 1998). The South Fork TMDL allocation for road surface erosion is 71 tons per square mile per year, of I which 85% is controllable. By implementing this action plan, estimated sediment production can be reduced to 10 tons of sediment per square mile (a 93% reduction).

I The Eltapom Action Plan is divided into 3 phases. Phase I, the erosion assessment, has been implemented. Phase II, implementation of priority 1 sites has been submitted to I CDFG as a grant proposal. Phase III is the implementation of the action plan for priority 2 and 3 sites. To protect Eltapom Creek, Phases II and III should be implemented.

I SUMMARY I Eltapom Creek has important fisheries values which must be protected in order to ensure the recovery of South Fork Trinity River fisheries. The 4N09 road, both on private land and public land, is the main source of controllable sediment production in the watershed. I Shaping the road to outslope it where feasible, re-grading existing waterbars, and adding crushed rock to the road surface will eliminate most of the sediment production from the I road. Ditches which are turning into gullies can be treated by rock lining them and installing rock check dams. Erosion of fill slopes can be controlled by adding rock energy I dissipation mats to waterbar and culvert outlets.

The USFS roads are generally in good condition with the exception of the 4N09 road and a I few problem spots on other roads. Potential erosion problems exist on the 4N25 (plugged I culvert), 4N25D (partially plugged culverts), 4N25E (re-establish waterbars), 4N34A (deep I 33 I rills/ sediment production), 4Nll (partially plugged culverts), 4N11G (localized potential fill I failure along outer road edge), 4N24 (road slump). These problems can be treated with regular maintenance - re-establishing waterbars and cleaning culvert inlets. I I I I I I I I I I I I I I I I 34 I I

I REFERENCES

California Department of Fish and Game. 1996. Annual report. Trinity River basin I salmon and steelhead monitoring project 1993 - 1994 season. Sacramento, CA.

I California Dept. of Forestry and Fire Protection. 1983. Suggested culvert sizing procedures for 50-year storm. California Dept. of Forestry and Fire Protection. Fortuna, CA.

I California Dept. of Water Resources. 1981. Rainfall depth- duration- frequency for I California. Sacramento, CA Gordon, N., T. McMahon, B. Finlayson. 1992. Stream Hydrology. John Wiley & Sons. I New York, NY. Mayo, T.M. 1992. Trinity River basin restoration program, Eltapom Creek habitat typing I report, 1991. Prepared for USDI Bureau of Reclamation. USDA Forest Service, Shasta­ Trinity National Forest, Hayfork, CA.

I McLeod, D. 1995. McDonald Creek, Humboldt Co. (Field Note). California Department of I Fish and Game, Eureka, CA. Pacific Watershed Associates. 1994. Action plan for restoration of the South Fork Trinity I River watershed and its fisheries. Pacific Watershed Associates. Arcata, CA. Reid, L. M. and T. Dunne. 1984. Sediment production from forest road surfaces. Water I Resources Research, vol. 20, no. 11, pp. 1753-1761.

Renne, P., and G. Scott. 1988 Structural chronology, oroclinal deformation, and tectonic I evolution of the southeastern Klamath Mountains, California. in: Tectonics, v. 7, no. 6. pp. I 1223-1242. Trinity River Task Force, Technical Coordinating Committee. 1994. Trinity River fish & wildlife management program three year action plan, fiscal year 1995-1997. Weaverville, I CA.

I Truman, Patrick and Pacific Watershed Associates. November, 1996. Coordinated Resources Management Plan for the South Fork Trinity River. Weaverville, CA

I USDA Forest Service. 1994. A federal agency guide for pilot watershed analysis. I I 35 I

USDA Forest Service, Shasta Trinity-National Forest. 1996. Hayfork adaptive I management area draft implementation guide. Weaverville, CA.

US Environmental Protection Agency. 1998. South Fork Trinity River and Hayfork Creek I sediment total maximum daily loads. I US Geological Survey water resources data, Gauges 115284, 115285, 115287. US Geological Survey & California Department of Water Resources. I I I I I I I I I I I I I I 36 I I I APPENDIX 1 I Culvert Sizing Procedures Two methods were used for estimating culvert sizes - 1) the Rational Method and 2) the I Magnitude and Frequency Method (CDF 1983). Weaver and Hagans recommend using two or three methods and comparing the results. In all cases, the culvert is sized to convey I discharge during a 50 year storm event (D50). I Rational Method The advantages of this method are: 1. frequently used and flexible enough to take into account local conditions I 2. easy to use if local rainfall data is available

I The disadvantages are: 1. flexibility may lead to misuse, or misinterpretation oflocal conditions I 2. precipitation factor "I" may be difficult to obtain in remote areas The rational method is based on the equation: I Q = CIA where: Q = peak runoff at crossing I c = runoff coefficient (percent runofl) I = uniform rainfall intensity (inches per hour) I A = drainage area (in acres) I Magnitude and Frequency Method The advantages of this method are: 1. large data base used to develop equations I 2. includes precipitation, elevation, and drainage area in developing relationship I 3. relatively easy to use Disadvantages are: I 1. each equation encompasses a large diverse area, which tends to overestimate some areas and underestimate others I 2. vegetation conditions are not directly included as a factor The equation for the magnitude and frequency of flood method is : I I 37 I

Q50=8.57 A0.87 p0.96 H-0.08 I where: Q = predicted peak runoff from a 50 year storm (in cfs- cubic feet per second) 50 A =drainage area above crossing (in square miles) I P = mean annual precipitation (in inches) H =altitude index in thousands offeet (i.e., 2000 ft.= 2.0) I Culvert Sizing - 4N09 Rd I Mile 0.35 - current pipe - 24 inch X 20 ft. CMP Rational method: I Q=CIA C= 0.3 (from "Table of C Values," Rantz 1971); I =2.25 (from "Rainfall Depth-Duration­ Frequency for California," DWR 1981), A = 184 acres I Q= 0.3 X 2.25 X 184 = 124 cfs nso= 52 inches I

Applying a Q of 124 cfs to figure Al, the proper size culvert is determined by drawing a line for entrance type 3 (projecting) and an HW/D (headwater I diameter ratio) of 1.5, through a I discharge of 124 cfs. A 52 inch diameter culvert is needed to withstand a 50 year runoff event. I Note: The "I" value of 2.25 from the DWR 1981 table should be compared to the "I" value I derived by determining the time of concentration (Tc). Tc=fll.9 L310.385 H where: I L =length of channel (in miles) upstream of the crossing H= elevation difference between highest point in the watershed and the crossing (in feet). I In this case, L= 0.8 miles, H = 836 feet; Tc= .15 hours (9 minutes). The rational method requires the "I" value to be expressed in hours, therefore the Tc needs to be multiplied by I 6. 7. From the Grizzley Flat depth- duration - frequency table, the 10 minute maximum precipitation is 0.37, therefore the one hour precipitation ("I" value) is 0.37 X 6. 7 = 2.48. This is almost the same "I" value as the one derived from the DWR 1981 table. I Using a value of 2.48 instead of 2.25, the Q is 0.3 X 2.48 X 184 = 137 cfs. To withstand a 50 year runoff event, a 54 inch diameter culvert is needed, i.e., the results are very close to I those derived using an "I" value of 2.25.

Magnitude and Frequency Method: I Q5o=8.57 A0.87 p0.96 H-0.08 I 38 I I

I A= .2875 sq. mi. H= .836 I Q5o=8.57 (.2875)0.87 (7o)0.96 (.836t0.08 Q5o= 173 cfs I D50= 52 inches Discussion I During the road survey the culvert was inspected for erosion problems such as plugged inlet, eroding outlet, evidence of overflowing, etc. The culvert did not display signs of erosion I problems, plugging, or overflowing. The magnitude and frequency method is probably an over-estimate of the size of pipe needed, based on the size of the stream channel and lack of I evident erosion problems. Even a 48 inch culvert seems over-sized for the channel. Before replacing this pipe, the size necessary to withstand a 50 or 100 year flood should be calculated using the "Slope - Area Method" (using the Manning Equation to estimate I discharge). This method calculates the volume of flow which has actually occurred in the channel and by aging trees (taking a core sample with an increment bore) or looking at other I flood estimators within the flood plain, an estimate of the 50 year or 100 year flood can be made more accurately than from the office based techniques.

I Mile 0.94 - current pipe - 24 inch X 20 ft. CMP Rational Method: I Q=CIA C= 0.3; I =2.25; A = 107 acres I Q= 0.3 X 2.25 X 107 = 72 cfs Hw!D= 2.0 I D50= 38 inches

Magnitude and Frequency Method: I Q50=8.57 A0.87 p0.96 H-0.08 A= .17 sq. mi. I H= .968 Q5o=8.57 (.17)0.87 (7o)0.96 (.968t0.08 I Q5o= 173 cfs I D50 = 45 inches Mile 1.27 - current pipe - 36 inch X 20 ft. CMP I I 39 I

Rational Method: I Q=CIA C= 0.3; I = 2.25; A = 400 acres; Hw/D= 2.25 I Q= 0.3 X 2.25 X 400 = 279 cfs D50 = 62 inches I Magnitude and Frequency Method: Q5o=8.57 A0 .87 p0.96 H-0.08 I A= .63 sq. mi. H= 1.15 I Q5o=8.57 c 63)o .87 <7o)0.96 (Ll5to.o8 Q5o= 335 cfs D50 = 68 inches I

Mile 2.20 -- current pipe - 18 inch by 30 ft. CMP I Rational Method: Q=CIA I C= 0.3; I =2.25 ; A = 11 acres, Hw/D= 2.0 Q= 0.3 X 2.25 X 11 = 7.4 cfs D50 = 16 inches I

Magnitude and Frequency Method: I Q50=8.57 A0 .87 p0.96 H-0.08 A= .17 sq. mi. H= .968 I Q5o=8.57 co17)0.87 (7o)0.96 (.3oot0.08 Q5o= 14.6 cfs I D50 = 20 inches I Mile 2.47 - current pipe - 18 inch by 30 ft. CMP Rational Method: Q=CIA I C= 0.3; I =2.25 ; A = 11 acres, Hw/D= 2.0 Q= 0.3 X 2.25 X 11 = 7.4 cfs I D50= 16 inches I Magnitude and Frequency Method: Q50=8.57 A0 .87 p0.96 H-0.08 I 40 I I

I A= .017 sq. mi. H= .472 I Q5o=8.57 c.017)0.87 (7o)0.96 (.472t0.08 Q5o= 14.6 cfs I D50 = 20 inches Mile 3.03 - current pipe - 18 inch X 30 ft. CMP I Rational Method: Q=CIA I C= 0.3 ; I =2.25 ; A = 5 acres, Hw/D= 2.0 Q= 0.3 X 2.25 X 5 = 3.4 cfs I D50= 14 inches Magnitude and Frequency Method: I Q5o=8.57 A0.87 p0.96 H-0.08 A= .008 sq. mi. I H= .200 Q5o=8.57 c.008)0.87 (7o)0.96 c.2oot0.08 Q5o= 7.6 cfs I D50 = 16 inches

I Mile 3.28 - current pipe - 18 inch X 30 ft. CMP Rational Method: I Q=CIA C= 0.3 ; I =2.25 ; A = 14 acres, Hwill= 2.0 Q= 0.3 X 2.25 X 14 = 9.5 cfs I D50= 1 7 inches

I Magnitude and Frequency Method: Q5o=8.57 A0.87 p0.96 H-0.08 A= .02 sq. mi. I H= .525

Q5o=8.57 c.o2)o.87 <7o)0.96 c. 2oot0.08 I Q5o= 16.8 cfs I D50 = 21 inches I I 41 I

Mile 3.43 - current pipe - 30 inch X 30 ft. CMP I Rational Method: Q=CIA I C= 0.3 ; I =2.25 ; A = 58 acres, Hw/D= 3.0 Q= 0.3 X 2.25 X 58 = 39 cfs I D50= 27 inches

Magnitude and Frequency Method: I Q5o=8.57 A0 .87 p0.96 H-0.08 A= .09 sq. mi. H= .525 I Q5o=8.57 c.09)0.87 C7o)0.96 (.525)"0.08 Q5o= 62 cfs I D50 = 32 inches I Mile 3.88 - current pipe - 30 inch X 30 ft. CMP Rational Method: I Q=CIA C= 0.3 ; I =2.25 ; A = 65 acres, Hw/D= 3.0 Q= 0.3 X 2.25 X 65 = 44 cfs I D50= 28 inches I Magnitude and Frequency Method: Q5o=8.57 A0 .87 p0.96 H-0.08 A= .10 sq. mi. I H= .900

Q5o=8.57 c.io)0.87 c7o)0.96 c. 9oot0.08 I Q5o= 69 cfs D50 = 33 inches I I I I I 42 I I Figure A-1 I ~ 10,000 ( I ) - 8,000 t 6 000 (2) 156::~I ' 6. I -t:- ~.ooo 144 (3) f- 4,000 5. &. 132 . r..... 3,000 ;a 5. 6 . I 120 u ~ 5. ... 2,000 ... e- 4 . c :: 101 i 4 . I -E ~ 1,000 3. - 800 r f 3. - 84 :- 600 LI 2. I - ~00 ~ [. ~ - 400 r r 2. (/) t2. l&.I :::- 300 I.~ r I u (/) - ~ : 13 ~ 200 (/) ~ 1.5 ~ c:: 0 ,_'"' t'-' I IOI .... ~ ...... ------+------...---- c:: < l&.I 41 ...... c > ...... -l ...... :l ...... I ...... 1.0 "' 42 "'"0 1.0 ' c:; 161 a:; .... _ti!' SCALE ENTRANCE I 161 l&.I D TYPE .... .9 :E ct ct (I) ~ .8 c c (Z) < 30 -I- •lt•r•• t• ceftfOf'• ~ -I- , l&.I .8 I u ...... ~-+------+------!----- Q 27 ac c .7 0 'Z' I ...c 24 ~ 7 .7 CD Te ... acele IZl ., (3) , .., ••, 21 ••rl ..AHllJ I• acate (I), ,.,.. II& 1rrai9at iHll- li•e l~r ..91 I D eH q 1cete1., ec- , ..., .. ec .6 18 i•••atrete4. I I~ L -~ l 1.0 .5 I 12 EXAMPLE HW/D = 1. 0 I Entrance type = (3) BUREAU O" PIJllLIC ROADS JAr<. IM3 Disc~a=ge = 150 cfs Result : I Diamete= of culve=t = 66 inc~es I I 43 Table 1. Eltapom Watershed Roads I

Road Number Length (miles)• Driven (Y or N) · Walked (Y or N) Erosion Problems* I •within Eltapom waterhsed I 3N36D & E 0.40 i N N 4N02 I 0.80 N I N I 4N02A I 0.15 N N I 4N04 I 0.60 N I N l 4N04 spur 0.60 N N i 4N07 0.40 . N N - - 4N07A 0.20 N N I - - 4N09 6.30 y y s 4Nll 2.80 y I N - - w 4NllG 1.25 y N w 4Nl8 1.20 N l N I 4N24 I 2.80 y : N NS

4N24B I 0.75 y N N 4N25 4.80 y N NS I I 4N25B 0.35 N I y NS 4N25C I 1.30 N y NS 4N25D 0.45 N y NS 4N25E 0.30 N I y NS I 4N27 1.30 N I y NS 4N27A 0.50 1 N 1 y NS 4N34 0.60 ! y l N NS 4N34C 0.15 N I N I 4N34D 0.15 N N 4N34E I 0.15 : N I N 1 4N39 i 1.85 N N 4N39A 0.15 N N I 4N39B 0.75 N N 4N39C I 0.45 N I N 4N41 (map labels it 4N14) I 1.301 y N NS 1 i y I 4N41A (map labels it 4N14A) 1.25 N I NS 1 iN43 (+A) 1.25 y I N NS 4N43B i 0.20 1 y N NS 1 4N45A ! 0.20 N N I 4N45B I 1.301 N I N 4N46 ----- 1.00 N : N 4N47 I 0.10 . y I N NS 4N48 1.45 N N I 4N48A 0.75 N N y 4N49 i 2.10 N NS 4N49A : 0.80 N N I 5N09 I 0.65 y N NS I 5N09E I 0.50 N I N 5N60 10.00 y N N 5N60G - 0.15 N y NS 5N60H 0.15 N y NS I McBride I 0.20 1 N y NS Sierra Pacific : i.oo : N : N I Skunk Ranch I 0.40 N I y NS TrincoA & B i 2.00 N I y s I miles of road reviewed 31.00 I ------! TOTAL I 58.25 miles of road per souare mile I 2.99 area of roads (so. ft.) 3,075,600 I area of roads (acres) I 70.61 i I *N= none I I I *NS= not sienificant, minor erosion, no treatment *S= sienificant - warrants treatment I I *W= has erosion notential warrants monitoring I I 44 I I Table 2. Precipitation at Hyarnpom, Hayfork, and Big Bar

I §o~rce : - CA. D~t . of_Water Resources. 1981. Rainfall depth- duration- frequency for California. Sacramento, CA; and CA. Dept. of Water Resources/ Division of Flood Management Web Site. 1998 I year! Hyampom! Hayforkl Big Bar I

1 I I 1948 53.54 , I I 1949 29.81 I 1950 36.61 1 28.9 1951 56.221 42.17 1952 50.981 44.13 I 1953 52.43 41.18 1954 45.28 i 40.2 1955 , 33.9 25.05 1956 60.94 50.36 I 1 -- 1957 40.96 27.53 1958 1 67.55 1 54.39 I 1959 i 39.1 30.81 1 f-- I 1960 34.12 27.88 1961 39.32 30.81

- -- 1962 32.46 24.26 1963 48.2 38.83 I 1964 34.08 26.68 1965 54.18 38.77

1966 -- 40.11 29.46 1967 i 34.06 I 1968 31.91 1969 45.561 1970 41.71 ; I 1971 1 42.24 1972 I 28.04 1973 34 1974 I 53.89 I 1975 1976 1977 47.45 1978 -- - -·- I 1979 23.77 1980 1981 ------1982 1 I I -~ - -- . 1983 1 I 56.14 1984 43.31 1985 I 29.66 I 1986 45.77 1987 28.74 1988 30.39 1989 41.48 I 1990 27.31 - 1991 I 22.12 1992 23.53 1993 1 I 44.62 I 1994 20.77

1995 I 56.91 1996 I I 42.07 I 1997 42.91 1998 54.87 AVERAGE 44.73 36.45 38.16 EXTREMES: I MINIMUM 29.81 23.77 20.77 MAXIMUM 67.55 , 54.39 56.91 I I 45 Table 3. Rainfall Depth - Duration · Frequency for Hayfork and Hyampom I

Source: CA. Dept. of Water Resources. 1981. Rainfall depth-duration-frequency for California I I I ' I I I i Hyam:eom IHyam:eom IHyam:eom IHayfork I Recurrence interval 1 hr. precipitation 6 hr. precipitation :24 hr. precipitation1 24 hr. preci:eitation I ~· I 0.36 1.371 3.471 2.901 I 10 yr. I 0.57 2.15 ~ 5.451 4.55 1

25 yr, I 0.67 3.88 6.391 5.34! 50 vr. I 0.74: 2.78 ' 7.071 5.901 I I I I I I I I I I I I I I I

46 I I Table 4. Flow Extremes, South Fork Trinity River below Hyarnporn

I ANNUAL MAXIMUM SERIES-USGS GAUGE 11528700 I SOURCE- US GEOLOGICAL SURVEY WATER RESOURCES DATA, CALIFORNIA SOUTH FORK TRINITY RIVER BELOW HYAMPOM Notes: DRAINAGE AREA- 764 SQ. ML RI= n+l/rank I EXTREMES: MAXIMUM- 88,000 CFS (EST.)(12/22/64); MINIMUM- 14 CFS (8/24/77) Probability= 11 RI ESTIMATED BANKFULL Q- 19,400; BANKFULL QI SQ. ML- 25.4 CFS Bankfull Q= RI of aoo. 1.6 I I I I I n=32 BY CHRONOLOGICAL ORDER BY ORDER OF MAGNITUDE, HIGHEST TO LOWEST I I WATER YEAR! PEAK Q VIINIMUM WATERYEARI PEAKQ RANK PROBABILITI RECURRENCE INTERVAL 19661 30,800 69 19861 75,000 1 0.0303 33.00 1967 1 32,000 60 1983 73,300 2 0.0606 16.50 I 1968 1 32,0QQ__ 63 19741 69,300 3 1 0.0909 11.00 1969 , 42,100 1 62 1997 61,400 4 1 0.12121 8.25 1 1970 1 59,100 1 47 1970 1 59,100 5 0.1515 1 6.60 1 - 1971 41,100 46 1982 55,000 6 0.1818 1 5.50 I 1972 20,800 57 1995 48,100 1 7 0.2121 4.71 25,800 1993 47,000 - - 1973 38 8 0.24241 4.13 1974 69,300 64 1969 42,100 9 0.2727 3.67 1975 30,600 66 1971 41,100 1 10 0.3030 1 3.301 I 1976 12,700 58 1968 32,000 11 0.3333 3.00 -- 1977 ' 620 1 14 1967 1 32,000 12 0.3636 1 2.75 1978 26,000 44 1966 30,800 1 13 1 0.3939 2.54 19791 8,1201 39 1975 1 30,600 1 14 0.42421 2.36 I 1980 28,000 44 1980 28,000 15 0.4545 1 2.20 1981 18,100 I 30 1978 26,000 16 0.4848 1 2.06 1 19821 55,000 70 1973 1 25,800 17 1 0.51521 1.941 1983 1 73,300 1 91 1987 20,800 18 0.5455 1 1.83 I 1984 14,900 83 1972 1 20,800 19 0.5758 1.74 1985 1 12,300 1 50 1996 20,300 20 1 0.6061 1.65 19861 75,000 1 53 1988 18,800 21 0.6364 1.57 I 1987 ' 20,800 20 1981 ! 18,100 22 0.6667 1.50 1988 1 18,800 17 1984 , 14,900 23 0.6970 1.43 1989 1 14,600 I 29 1991 14,600 24 1 0.7273 1.38 1990 1 11,600 1 54 1989 1 14,6001 25 0.7576 1 1.32 I 1991 1 14,600 i 26 1976 1 12,700 26 1 0.7879 1.27 1992 ~,530 1 23 1985 12,300 27 1 0.8182 1.221 1993 1 47,000 1 25 1990 11,600 28 0.8485 1 1.18 1994 6,160 1979 8,120 29 0.87881 1.14 I 1995 1 48,100 1994 6,160 30 0.9091 1.10 1 19961 20,300 1 1992 5,530 31 0.9394 1.06 1 1997 1 61,400 I 19771 6201 321 0.9697 1 1.031 AVERAGE I 30,517 48 I I I BANKFULLQ ! -19,400 1 BANKFULL QI SQ. MI.- 19,400/764= 25.4 CFS I I highest g I 75,000 1 lowest Q I 14 ' I est. '64 Q I 88,000 1 average low flow Q 48 highest Q/sq. mi. 1 98.171 lowest Q/sq. mi. I 0.018 es_t. '64 Q/sq. mi ' 115.18 1 average low flow QI sq. mi. , 0.063 El~E_om area= ' 19.50 1 I I est. bankfull Q I 495 1 est. average low flow Q 1.23 est highest Q ' 1,9141 est. lowest flow Q 0.357 I I est. '64 2,246 ' I I I I I I 47 I I I I I I I I I I I I I I I I I I I I

I APPENDIX 2 - ELTAPOM CREEK ROAD SURVEY PHOTOS I I I I I I I I I I I I I I I I I 49 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

Roll 8/98-1, Photo 22

8/31/98 I Eltapom Creek waterfall I at - 0.6 miles from the South Fork Trinity River I I I I I

Roll 6/97-1, Photo 15 I

6/6/97 4N09 Rd., west of 5N60 I mile 1.13 gully I I I I I I A2 - 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 6/97-1, Photo 10 6/6/97 I Eltapom Creek watershed

4N09 Rd., mile 0.05 I I I I I I

Roll 6/97-1, Photo 16 Roll 9/98-1, Photo 13 I 6/6/97 9/'25/98 I Eltapom Creek watershed Eltapom Creek watershed 4N09 Rd., mile 1.13 4N09 Rd., mile 0.13 I I I I I I A2 - 2 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ----• -----M••-- I I I I Roll 9/98-1, Photo 14 9/25/98 I Eltapom Creek watershed

4N09 Rd. , mile 0.45 I I I I I

Roll 6/97-1, Photo 11 I 6/6/97 I Eltapom Creek watershed 4N09 Rd., mile 0.46 I I I I I I A2 - 3 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

Roll 6/97-1, Photo 12 I 6/6/97 I Eltapom Creek watershed 4N09 Rd., mile 0.55 I I I I I

Roll 9/98-1, Photo 15 I 9/25/98 I Eltapom Creek watershed 4N09 Rd., mile 0.55 I I I I I I A2- 4 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

Roll 10/98-1, Photo 4 I 10/21/98 I Junction of 4N09 Road & 5N60 I looking northeast I I I Roll 10/98-1, Photo 2

10/21/98 I 4N09 Road, east of 5N60 I Station 0+ 186 looking southwest I I

Roll 10/98-1, Photo 3 I 10/21/98

4N09 Road, east of 5N60 I Station 0+300 I looking northwest up road I I I A2 - 6 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 10/98-1, Photo 1 10/21/98 I 4N09 Road, east of 5N60 I looking northeast to station 0 + 186 I I I Roll 10/98-1, Photo 5 10/21/98 I 4N09 Road, east of 5N60 I looking northwest to station 0+620 I I

Roll 10/98-1, Photo 6 I 10/21/98 I 4N09 Road, east of 5N60 I looking northwest to station 0+620 (closeup) I I I A2 - 7 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 10/98-1, Photo 10 Roll 10/98-1, Photo 8 10/21/98 10/21/98 I 1+270 power line spur rd. 1+270 power line spur rd. off 4N09 Road, east of 5N60 off 4N09 Road, east of 5N60 I looking east to station 0+430 to 0+500 looking northwest down road from station 0+320 I I

Roll 10/98-1, Photo 11 I 10/21/98 I 1+270 power line spur rd. off 4N09 Road, east of 5N60 I Roll 10/98-1, Photo 12 closeup of 0+482

10/21/98 I

; 1+270 power line spur rd. off 4N09 Road, east of 5N60 I looking east to station 0+557 Roll 10/98-1, Photo 13 I 10/21/98

3+060 power line spur rd. I off 4N09 Road, east of 5N60 I looking north to station 0+250 I I I

A2- 8 I

I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 10/98-1, Photo 14 10/21/98 I 3+060 power line spur rd. off 4N09 Road, east of 5N60 I looking north to station 0+250 I I

Roll 10/98-1, Photo 17 I 10/21/98 I 4N09 Road, east of 5N60 I looking east from station 2+240 I ; I

Roll 10/98-1, Photo 18 I 10/21/98 I 4N09 Road, east of 5N60 I looking east at station 2+590 I ' I I

A2- 9 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 10/98-1, Photo 23 Roll 10/98-1, Photo 21 10/21/98 10/21/98 I 4N25 Road 4N27 Road I plugged culvert at mile 1.45 well built waterbar at station 5+111 I I

Roll 10/98-1, Photo 24 I 10/21/98 I 4N25 Road, mile 1.45 spur road I looking up road at waterbar I ' I Roll 10/98-1, Photo 25 I 10/21/98 I 4N25 Road, mile 1.45 spur road I looking down road at waterbar I I I

A2 - 10 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Roll 10/98-1, Photo 7 10/21/98 I 1+270 power line spur rd. off 4N09 Road, east of 5N60 I looking east up road to station 0+ 150 I I

Roll 10/98-1, Photo 19 I 10/22/98 I 4N27 Road I Roll 10/98-1, Photo 16 functioning berm drain at station 3+316

10/21/98 I . 4N09 Road, east of 5N60 I non-functioning berm drain Roll 10/98-1, Photo 15 I at station 2+070 10/21/98 I 4N09 Road, east of 5N60 I non-functioning berm drain at station 2+070 I I I

A2 - 11 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I