hydrology report conner creek fish passage improvement...

Hydrology Report

Conner Creek Fish Passage Improvement Project USDA Forest Service Region 5

Shasta-Trinity National Forest

Trinity River Management Unit (TRMU)

Prepared by: /s/ Mark S. Lancaster CA Registered Professional Forester

Five Counties Salmonid Conservation Program Northwestern California Resource Conservation and Development Council

Reviewed by: /s/ Fred S. Levitan

West Zone Hydrologist Shasta-Trinity National Forest

June 15, 2011

Conner Creek Fish Passage Improvement Project - Hydrology Report – June 15, 2011

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I. Description of Proposed Project The Five Counties Salmonid Conservation Program (5C)1 in cooperation and partnership with the Trinity County Department of Transportation (DOT) proposes to replace the existing culverts on Conner Creek at Red Hill Road (County Road 415) and Conner Creek Road (County Road 449). Red Hill Road is the sole access and egress route for the Cooper’s Bar Estate subdivision and Red Hill Lake neighborhoods, providing access to more than 100 private parcels and/or homes. It also accesses Forest Service Road 33N41 and the Hocker Meadow area, the main route to the upper elevations of the Conner Creek watershed. Conner Creek Road is a dead end road that serves approximately 10 private parcels and homes.

The project is located in Section 2 T 33N, R 11W MDBM. Crossing #1 is at milepost 0.06 on Conner Creek Road and Crossing #2 is at milepost 2.4 on Red Hill Road (Figures 1-3). The project is located in the Conner Creek-Trinity River 7th-field subwatershed and Conner Creek is a fourth-order perennial tributary to the Trinity River (Table 1).

Table 1. Conner Creek Fish Passage Improvement Project watershed hierarchy

HUC4 (Subbasin)Level 18010211Code Trinity River

HUC5 (Watershed) 1801021109 Canyon Creek

HUC6 (Subwatershed) 180102110803 Lower Canyon Creek

HUC7 (Drainage) 18010211080306 Conner Creek-Trinity River

Both stream crossings create backwater conditions during moderately high flows (~Q15); the roads overtop during larger flows (Q18 and Q43) and prevent upstream migration for salmonids and resident trout during nearly all flows. The proposed project will replace the existing culverts with structures designed to allow fish to migrate upstream, convey the Q100-year storm flows and allow improved downstream transport of bedload, wood and debris. While the project was recognized as a priority following the Trinity County Migration Barrier Inventory (conducted between May 2001 and June 2002) of stream crossings on county roads (Taylor, 2002), the need for the project increased following the 2008 Eagle Fire which burned the upper 41% of the Conner Creek watershed within the Eagle Inventoried Roadless Area. The project is proposed because the existing crossings are inadequate to meet federal, state and local goals, policies and objectives for threatened and endangered species conservation and recovery. The crossings fail to meet water quality objectives (refer to Section IV). Specifically, the current stream crossings are deficient because:

• They prevent nearly all upstream migration of adult and juvenile salmonid fish species and the outlet jumps at both crossings exceed 1+ feet, limiting juvenile salmonid passage during all flows (Taylor 2002; refer to Figure 3);

• The existing offset baffles that line half of the concrete box culvert floor on Conner Creek Road jam with debris and are ineffective at improving adult migration following larger storm flows (Figure 3);

• Both stream crossings impede natural bedload, wood and debris transport; • Both stream crossings have the potential to overtop and fail, cutting off access to over 100 private

parcels and access to public lands;

1 A non-profit program within the Northwestern California Resource Conservation and Development Council (RC&D); refer to www.5counties.org for additional information.

http://www.5counties.org/


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• Both stream crossings, if they were to fail, could yield 750-2,189 cubic yards (yd3) of sediment to Conner Creek (5C DIRT Inventory, 2001; DOT 2011).

• The 2008 Eagle Fire in the upper portions of the Conner Creek watershed increased the potential peak discharge of small to moderately large storms for the short and mid-term periods. Additionally, the fire increased the potential for sediment, bedload and debris transport (USFS, 2008).

Figure 1. Project Location Map


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Figure 2. Crossing (#1 and #2) Locations

Figure 3 (photos above). Red Hill Road perched outlet and jump (left); Conner Creek Road crossing offset baffle debris jam (center) and Conner Creek Road outlet jump (right).

Figure 4 (photos below). Multi-plate arch set on concrete abutments on a nearby comparative

watershed (Soldier Creek at Evans Bar Road). The left photo is similar to the proposed structure to be installed on Red Hill Road, while a bridge similar to one installed on Little Browns Creek at

Roundy Road (right) would be installed on Conner Creek Road.


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Conner Creek is designated as critical habitat for threatened coho salmon by NOAA’s National Marine Fisheries Service (NMFS) and as a tributary to the Trinity River, it is designated as impaired by excess sediment and siltation and excess water temperature under Section 303(d) of the Clean Water Act by the State Water Resources Control Board. There is an EPA-approved sediment Total Maximum Daily Load (TMDL) in place for the Mainstem Trinity River system (EPA, 1999). The five-acre project area and stream crossings are located within designated Riparian Reserves under the Northwest Forest Plan (NWFP) and the Shasta-Trinity National Forest Land and Resource Management Plan (Forest Plan), as it lies within 300 feet of a fish-bearing perennial stream (Conner Creek). One acre of the proposed project area (Conner Creek Road staging area) is outside of Riparian Reserves, but all proposed project activities will meet the Aquatic Conservation Strategy Objectives. Additional details regarding application of all applicable environmental laws and regulations are provided in Section IV below.

The proposed project would remove the 10-foot diameter corrugated metal culvert at Red Hill Road (Crossing #2) and replace it with an 18-foot wide, embedded metal plate arch culvert. It would also remove the 18-foot long, 6-foot tall, 14-foot wide concrete box culvert at Conner Creek Road (Crossing #1) and replace it with a 24-foot wide by 7-foot tall bridge (14-foot wide travel way). Specific information for each Crossing is provided below.

Red Hill Road (Crossing #2): The existing 10-foot diameter, 66-foot long corrugated metal (CMP) culvert would be replaced with an embedded 18-foot wide, 12-foot tall, 70-foot long multi-plate arch culvert set at a maximum 5% gradient (refer to Figure 4 for a similarly designed project in the Junction City area). The new stream crossing gradient would be consistent with the average channel gradient in the area of 5%. The project would not require the installation of headwalls, flared inlets/outlets or other inlet/outlet controls, except for minor rock slope protection (RSP). This design minimizes the disturbance to riparian vegetation outside of the road fill prism during construction. The increased road width could eliminate the need for guard rails (to be determined by DOT engineering staff).

Figure 5. Red Hill Road Crossing (#2)


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A Bailey bridge would be installed over the crossing once the road base and portion of the roadfill material are excavated to allow for installation. The Bailey bridge will allow for full excavation of the remaining roadfill, existing culvert and remaining construction activities while providing for one-way traffic throughout construction. The excavation is expected to be approximately 22 feet wide at the bottom and approximately 60 feet wide at the top and 70 feet long, with an average 12-foot depth. Approximately 740yd3 of material would be excavated. The multi-plate arch structure would be assembled within the excavation area and approximately 460yd3 of fill would be reincorporated into the roadfill after the new structure is constructed. The roadfill slopes would be at reconstructed at the same angle as the existing fill (1½:1). Spoils material would be stored the existing open, flat staging areas for re-use in the project. Any excess material (~280yd3) would be stored at a pre-approved disposal site or recycled at a DOT yard. All material will be stored in a manner to not deliver to a watercourse.

Approximately 20% (or 2 feet) of the bottom of the new arch crossing (~85yd3) would be embedded with D5-D85 particle size engineered stream channel mix and a low flow channel would be shaped within the crossing floor. The engineered streambed will be placed, the low flow channel shaped and the bed jetted to seal the voids in the streambed material. Rock weirs/ribbons may be installed within the crossing to define the low flow channel and provide grade control at 5%. A rock ribbon consisting of 1 to 2 ton boulders would be set in the existing outlet pool for grade control and the pool would be backfilled with engineered streambed mix and sealed. The rock ribbon would be set 6 inches below the designed streambed elevation. The channel gradient from the downstream control point (tailwater control for the outlet pool) to above the upstream rock ribbon would conform to the average 5% channel gradient in this reach.

The new crossing would span the 12 to 14-foot active channel width as well as the 2-year channel width, but would not have a 1:1.5 ratio associated with a stream simulation design project. The current crossing (~79ft2 surface area) can convey less than the 20-year flow before it backwaters and requires active management for removal of large wood debris accumulation at the inlet. The road overtops on the 43-year flow and the new design (~144 ft2 surface area) would convey the 100-year recurrence interval flow and provide for more efficient transport of bedload and debris.

While stream and groundwater dewatering would not be necessary during excavation of the roadfill material (initial construction phase), surface water re-routing and groundwater seepage controls would be installed during the subsequent removal of the existing metal culvert, installation of the multi-plate arch, excavation and placement of two sub-grade grade control boulder ribbons and placement of the engineered stream bed material. Dewatering and fish exclusion fencing placement would be conducted consistent with BMPs and species relocation would be conducted by a qualified fisheries biologist. Fish, if present, would be relocated to areas both upstream and downstream of the fish exclusion fencing (for complete details on fish exclusion fencing installation and location and channel reach dewatering, refer to the project Fisheries Biological Assessment and Evaluation). Channel dewatering should only be necessary for 3 to 4 weeks.

Approximately 37 sapling sized trees (<1” diameter), 24 small trees (1” to 6” diameter), 12 medium sized trees (6” to 12” diameter) and two larger big leaf maples (19” and 22” diameter) would be removed from the road prism. Cores from two trees indicate that the older trees in the road prism are approximately 50 years old. Trees to be removed include white alder, big leaf maple, madrone, ponderosa pine, incense cedar and Douglas fir. Other shrub/ground species to be removed from the road fill include wild grape, English ivy, poison oak and small amount of native and non-native grass species. After installation of the new crossing, replacement of the roadfill and shaping of the fillslopes native grass seed and shrubs/tree species would be planted and mulched with rice straw, ground wood mulch or similar suitable weed-free mulch material. Portions of the fill face would be armored with RSP and/or cobble-sized material. Interim slope erosion control techniques such as silt fencing and large wood placement would be utilized on fill slopes (refer to BMPs in Section V).


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Conner Creek Road (Crossing #1): The existing 6-foot tall, 14-foot wide, 18-foot long concrete box culvert would be replaced with a pre-fabricated 7-foot tall, 16-foot wide, 40-foot long steel beam bridge. The freespan width would be 24 feet, more than 1.5 times the active channel width of the reference reach. The surface area of the new crossing floodplain is ~156 ft2 compared to the 70 ft2 floodplain of the existing opening. HEC-RAS2 modeling indicates that the crossing would be able to convey the 100-year peak flow (1,806 cfs) while the existing box culvert overtops at less than the 25-year recurrence flood interval (885 cfs). Removing the offset baffles would reduce the potential for debris accumulation within the crossing. The left bank would be in the current location of the existing wingwall. The right bank would be excavated back sufficiently to widen the active channel width to 24 feet and provide clearance for placing the new abutment. The new abutments would be 7 feet tall, 1 foot wide and 16 feet long. These abutments would sit on a 3-foot wide footing placed on a 6-foot deep concrete keyway that is set below the maximum scour depth.

Figure 6. Conner Creek Road (#1)

All excavation would be within the road prism and its associated toe slope. A “V” shaped low flow channel would be formed using D5-D85 sized engineered streambed material that would have a 1-foot drop from the edge of each stream bank to the center of the channel; representing an approximate 8.5% stream bank gradient. The low flow channel would not conform to the riffle and run habitat immediately upstream, but would maintain fish passage during low flows.

A detour bridge would be placed adjacent the existing roadway/culvert on the downstream end and the approaches will conform to the road shoulders. Minor rock placement would be placed to transition the approaches. Three alder trees may need to be trimmed or removed due to overhang near the existing culvert but if retention is deemed safe and feasible, every effort to retain all or the majority of the trees

2 Hydrologic Engineering Centers River Analysis System; completed by Trinity County Department of Transportation Engineering staff; March 2011.


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will be made. It is anticipated that the detour bridge would be needed for 1 to 2 weeks. There are no underground or overhead utilities to be relocated.

After aquatic species relocation, temporary bridge and stream diversion (clean water bypass) installation, the 3-foot wide, 6-foot deep, 16-foot long concrete footing (keyway) will be formed and placed in the existing roadway directly behind the existing culvert’s left bank abutment (abutment will be left in place as a support wall). This work will be completed outside of the active channel and there should be limited potential for ponding of groundwater and delivery of roadfill material to the stream. A 1-foot wide, 7-foot tall, 16-foot long abutment will be formed/placed atop the footing. A similar sized footing and abutment will be excavated and constructed on the right bank. This will also require excavation of the material between the right bank footing/abutment and the existing culvert (~120yd3). Once the footings and abutments have cured, structural backfill will be placed (~40yd3) to fill the voids behind the abutments and compacted with a manual whacker and/or other small equipment to compaction specifications. The box culvert will be left in place for the duration of footing excavation/placement and abutment construction. Once cured, the culvert will be excavated (with exception of the left bank abutment) and removed to the equipment staging area or DOT yard. Partially grouted rock slope protection (¼ to ½-ton boulders) will be placed at a 1:1 slope along the left bank wing wall for stabilization and scour protection. Engineered streambed material (D5-D85 size) will be placed and jetted to compaction in the crossing to form a low-flow channel (~20yd3), providing for fish passage at low flows. A rock-ribbon grade control structure (1 to 2-ton) will be installed 6” below the designed streambed elevation in the outlet pool area (already e-fished and dewatered). The outlet pool will be backfilled with D5-D85 sized streambed mix (~23yd3) and jetted to compaction. A similar grade control structure will be installed immediately upstream of the crossing. The rock slope protection/ribbons and streambed will be installed from the roadway using an excavator or other heavy equipment. After placement of all RSP and grade control, the pre-fabricated bridge deck will be set with a crane.

Dewatering would be necessary during excavation of the left wingwall, pouring of the left keyway and footing, during demolition of the box culvert, excavation and placement of the two grade control structures and construction of the new stream channel. Installation of fish exclusion fencing, species relocation and dewatering would be consistent with BMPs. Channel dewatering would be necessary for 1-2 weeks.

Guardrails would be installed prior to removal of the detour bridge. Paving would be completed at a later date. The entire construction window is estimated at 8 weeks.

II. Field Evidence Conner Creek Watershed Scale Conner Creek is a fourth-order perennial tributary to the Trinity River that flows through moderately steep terrain in a northeasterly direction. Elevations range from 1,450 feet at the mouth to 5,507 feet northeast of the Hayfork Divide. The majority of the watershed is within the Eagle Inventoried Roadless Area, with the lower part of the watershed located in rural residential areas of Junction City. Extensive mining activity in the lower reaches of Conner Creek modified the historic channel and altered conditions at the confluence with the Trinity River.

A Stream Condition Inventory (SCI) survey was completed by the USFS fisheries staff on a 2,290 foot reach upstream of Crossing #2 in 2007 (SCI records, Weaverville Ranger District). The 2007 SCI located 36 pieces of large woody debris (LWD) in the survey reach (equates to 83 pieces of LWD/mile). All pieces were at least 16” dbh, but only three were ≥ 50 feet in length (indicating non-functioning LWD recruitment). It is anticipated that LWD recruitment will increase over the next decade as a result of the Eagle Fire and the existing crossings on Red Hill and Conner Creek Roads presently require the removal of larger LWD from the channel to avoid plugging the culverts. In 2008, the Eagle Fire burned upslope of Red Hill Road, resulting in the loss of canopy and ground cover; a reduction in evapotranspiration rates; an increase in surface runoff and exposure of soil to


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erosion; a reduction of soil water infiltration; and an expected increase in overland flow and peak stream flows (Neary et al 2005, Swanston 1991). These changes will result in an overall increase in erosion and sedimentation at the watershed scale (erosion hazard rating is high; 2009 Burnt Ranch-Soldier Creek Watershed Analysis). Following the Eagle Fire, the Iron/Alps Hydrological Resource Assessment (HRA) was completed as part of the Burned Areas Emergency Response (BAER) assessment of the Iron/Alps BAER assessment (USDA Forest Service, 2008). The assessment indicated that 41% of the 7th-field Conner Creek subwatershed had moderate to low severity burning with high severity burning near the ridgetops (USFS, 2008). The HRA modeling also predicted a peak increase in 10-year recurrence runoff rates of 1.5 to 1.8 times compared to pre-fire conditions in the subwatershed. The 2009 Burnt Ranch-Soldier Creek Watershed Analysis (USFS, 2009) indicated that while fire impacts to hydrology are expected to recover to normal within 10 years, road impacts are permanent unless roads are decommissioned or restored to a hydrologically neutral state.

In addition to the Forest Service studies, the 5C Program has conducted photo monitoring of flows and debris movement within the project area since 2001 (refer to Figure 3). During empirical monitoring from winter 2008/2009 through present, higher turbidity levels and debris loading were observed after rainfall events at both stream crossings compared with observations made during rainfall events between 2006 and 2008 (Jordan, Biological Assessment and Evaluation for the Conner Creek Fish Passage Improvement Project). The higher debris loading may be attributed to downstream effects of the burned area in the upper watershed.

Cumulative Watershed Effects The Forest Service evaluates Cumulative Watershed Effects (CWE) at various levels of planning to initiate mitigation measures to minimize risk of significant adverse impacts on beneficial uses of water (R-5 FSH 2509.22, section 20.3). The Forest CWE analysis process evaluates potential impacts of land management on mass wasting, surface runoff, erosion and stream channel response. Watershed condition was documented in the Final Environmental Impact Statement (FEIS), Appendix H prepared for the Forest Plan (USFS, 1994). That analysis established Threshold of Concern (TOC) values for specific watersheds and documented watershed condition based on disturbance levels measured by the Equivalent Road Acre (ERA) methodology (Haskins, 1983). The ERA methodology documents past actions and converts disturbance levels to “roaded acres” for comparison and tracking. The amount of disturbed or impervious ground provides an index of rainfall-runoff response to the proposed actions, as well as a proxy for other indirect effects of disturbance (such as sediment mobilization and delivery). The ERA method can be used to evaluate and compare proposed future actions by predicting the added level of disturbance that would result from project implementation. Watershed condition based on comparison of ERA to TOC is defined as follows: Class I - ERA less than 40 percent of TOC (watershed condition is at or near potential); Class II - ERA between 40 and 80 percent of TOC (watershed condition is between potential and threshold of concern); Class III - ERA greater than 80 percent of TOC (watershed condition is close to, but below TOC). A recent CWE analysis for 7th-field HUC level watersheds across the Forest was completed in November 2008 in order to include the impacts of the 2008 fires on watershed condition (USFS, 2009b). The results of this analysis are summarized for Conner Creek in Table 2 below. The Conner Creek-Trinity River HUC7 is currently in Condition Class II. Condition Class II watersheds have a moderate risk of adverse cumulative effects from project activities.


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Table 2. Conner Creek 7th field sub watershed ERA values post 2008 fires.

Watershed Acres

TOC (%)

Fire ERA

Harvest ERA

Roads ERA

Current ERA3

% ERA

Current Risk Ratio

(%ERA / %TOC)

8,362 16 426.6 44.9 164.4 635.9 7.6% 0.48

The Eagle Fire increased ERA levels in many 7th-field watersheds, including Conner Creek and as noted above, monitoring has detected higher turbidity levels and debris loading at both stream crossings following the fire. It is likely that some hydrologic recovery related to vegetative regrowth and consequent reduction in runoff response has occurred since the post-fire analysis was completed, but given the high burn severity experienced in the upper watershed and the delay in sediment and debris routing time through the system to the drainage outlet, complete recovery is not anticipated on the order of 101 years.

In respect to water resources, beneficial uses of water, watershed condition, and stream and riparian habitat condition and quality, there is a need to restore stream connectivity and natural routing processes, notably given the upper watershed conditions from the Eagle Fire. The County road crossings were not adequately sized to convey large storm flows and associated bedload and debris prior to the Eagle Fire. The post-fire predicted increases in flows, bedload routing and debris transport that are anticipated over the next few decades will continue to affect hydrologic processes and fish habitat and threaten the integrity of the County roads. This project would improve hydrologic connectivity at the crossings without measurably increasing the ERA level.

Baseline Conditions for Conner Creek Unless otherwise noted, all baseline information for Conner Creek is from the SCI conducted in July 2007 by the Forest (USDA-FS 2007a).

Temperature Temperature measured at 58 degrees Fahrenheit at 1130 hrs on July 18, 2007. Temperatures of less than 67 degrees F are desired for a properly functioning stream.

Properly Functioning

Turbidity Conner Creek becomes turbid almost immediately after precipitation events due to a large landslide located upstream of Red Hill Road. Prior to the 2008 fires, the stream would clear within several hours and there were no other known turbidity problems in Conner Creek. As evidenced during higher flow events in 2009 through 2011, the upslope fire effects are contributing to higher runoff rates and increased turbidity levels.

At Risk

Chemical/Nutrient Contamination

Conner Creek has low levels of contamination from agriculture, industry and other sources; there were no excess nutrients detected.


Physical Barriers Culverts on County Road No. 449 and No. 415 serve as partial barriers to migrating fish (FishXing analysis of RED and GREY, 2000 Trinity County Migration Barrier Inventory).

Not Properly Functioning

This project will remove those barriers and

3 Includes past and present actions on Federal, State, Private lands (data from Burnt Ranch-Solider Creek WA, 2009).


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improve the baseline condition to Properly Functioning

Substrate The mean percent pool tail fines is 1.6% which indicates proper substrate function.


Large Woody Debris

Conner Creek has 83 pieces LWD per mile with 16-inch DBH, but only 3 exceed the 50-foot length. LWD amounts are expected to increase over the next decade due to the upslope fires.


Expected upward trend as a result of the Eagle Fire

Pool Frequency Conner Creek has 67 pools per mile. Frequency is one pool every 79 feet (1 pool every 4.8 bankfull widths - a properly functioning pool frequency would have at least one pool every 3-7 bankfull widths). There was only one pool with a 36 inch depth, which indicates improper function of pool maximum depth.


Off-channel Habitat

Conner Creek has minimal backwater habitat with cover and low energy off-channel areas.

At Risk

Refugia Conner Creek has minimal backwater habitat and minimal LWD but a high frequency of shaded pools. Shade measurements were taken at 50 locations within the survey segment and mean shade was 80%. The culvert barriers limit the usefulness of Conner Creek as refugia.


Width/Depth Ratio

Conner Creek is a Rosgen “B” type channel with a mean W/D ratio of 21.8. Width/Depth ratios greater than 12 are desired for properly functioning “B” channels. Mean entrenchment ratio was 1.3. Mean bank full and flood plain widths were 16.6 ft and 21.9 ft.


Streambank Condition

Conner Creek has 13% bank stability, 69% vulnerability and 18% instability.


Floodplain Connectivity

Conner Creek has minimal floodplain connectivity. Not Properly Functioning

Change in Peak/Base Flows

Cumulative watershed effects (CWE) modeling after the 2008 fires shows Conner Creek subwatershed in WCC II with the primary disturbance being the limited road network in the subwatershed and the 2008 fires.

At Risk

Increase in Drainage Network

Conner Creek has had a moderate increase in drainage density due to the road network in the northwestern section of the drainage and the high density of road networks in the lower watershed.

At Risk

Road Density and The Conner Creek subwatershed has 2.4 miles of At Risk


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Location roads per square mile, with two County roads located in the valley bottom and numerous short distance private roads.

Disturbance History

A CWE analysis was completed for the Down River Community Protection Project analysis area across numerous HUC5-HUC 8 watersheds in 2009 (takes into account effects of 2008 fires). That analysis showed that the Conner Creek subwatershed is at 47.5% of TOC, maintaining the WCC II level.


Riparian Reserves The Riparian Reserves of Conner Creek are characterized by wild grape, vine maple and elderberry along both banks. Abundant shade-tolerant vegetation including Pacific yew, Mountain dogwood and sword fern under an old growth overstory of Douglas-fir, Sugar pine and Ponderosa pine provide substantial canopy cover and opportunities for LWD recruitment.


Project Area Scale Watershed scale assessments have been completed as discussed above and flows and debris movement within the project area have been monitored by 5C Program staff since 2001 (refer to Figure 3). Boberg and Kenyon (CDFG, 1979), Ross Taylor and Associates (2001 and 2006) and TRMU fisheries biologist Loren Everest (2006) have also conducted assessments.

SHN Consulting (2006) and DOT (2010) design engineers conducted the hydraulic analysis and Taber (engineering geologists) completed a foundation and geotechnical analysis at Conner Creek Road (Taber, 2011). Thalweg profiles and cross section measurements were taken above, below and within the stream crossings. A reference reach was established approximately 300 feet upstream of Crossing #2, indicating an annual flow channel width of 14 feet with a 2-year recurrence width of 16 feet. The reference upstream of Crossing #1 has an annual flow channel width of 11 feet and a 2-year recurrence width of 14 feet. The average channel gradient through both reaches is 5%. The gradient between the tailwater control elevation and the top of the crossings averages 5% for both crossings as shown in Figure 7.


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Figure 7. Existing channel profiles at both sites

Recurrence intervals for the 5-, 10-, 25-, 50- and 100-year storm were calculated from Regional Flood-Frequency Equations for the North Coast Region of California with site-specific characteristics of annual precipitation, elevation index, and drainage area (DOT 2011). The recurrence intervals as derived from the North Coast Regional Flood-Frequency Equations are summarized in Table 3 below.

Table 3. Storm Flow Recurrence Intervals

Conner Creek Project

5-Year Flow (cfs)

10-Year Flow (cfs)

25-Year Flow (cfs)

50-Year Flow (cfs)

100-Year Flow (cfs)

Conner Creek Road: Crossing #1 353.4 504.6 709.7 947.5 1,806

Red Hill Road: Crossing Site #2 351.3 501.7 705.7 942.1 1,770

Both crossings exhibit past evidence of overtopping and diverting and the Eagle Fire has increased the potential for runoff, debris and bedload transport at the already restricted crossings. Crossing #1 is undersized for the 100-year storm flow and is estimated to overtop on an 18-year storm flow. This crossing is a complete barrier to all salmonid fish species and life stages during all migration flows, primarily due to the perched outlet and leap. The offset baffles within the box culvert are ineffective at improving passage and slowing flows as they clog with woody debris (Figure 3). Crossing #2 is also undersized for the 100-year flows and is estimated to overtop on a 43-year recurrence storm flow. This crossing is a partial barrier to salmonids and resident trout, violating CDFG passage criteria on 55% of migration flows. It is a complete barrier to all juvenile age classes and species, primarily due to the outlet leap and flow velocities within the culvert. The steel ramp baffles most likely improve adult passage, but are ineffective at reducing velocities during migration flows to levels that


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provide for effective juvenile passage. Upgrading Crossing #2 necessitates upgrading Crossing #1 to allow passage of higher levels of large woody debris anticipated over the next decade.

Table 4. Comparison of existing and desired condition associated with the Conner Creek Fish Passage Improvement Project

Existing Condition • Stream crossing culverts present either a partial or total upstream

migration barrier for adult and juvenile anadromous salmonids. • Stream crossing culverts are undersized for the 100-year return interval

storm flows and exhibit past evidence of overtopping and diversion.

Desired Condition

• Stream crossing culverts replaced and/or modified to allow for passage of adult and juvenile steelhead and coho salmon during the full range of migration flows.

• Stream crossing culverts replaced and/or modified to convey 100-year flows for the watershed (estimated at 1,155 cfs).

At both crossings there is minimal evidence of active erosion either on stream banks or within the active channel areas; there is well developed tree and shrub canopies upstream and downstream of the crossings. A pebble count completed during the 2007 SCI (Figure 8) showed limited quantities of clay to sand-sized particles in the bed matrix. Rather, the channel consists of predominantly larger particles consistent with a high gradient, high energy channel. Approximately 1% of the stream bed consists of fine gravel (~6 mm) with the median particle size being coarse gravel (~48mm). Approximately 12% of the channel material consists of large boulders and bedrock. The geotechnical foundation report (Taber, 2011) indicates similar conditions exist to a depth of 7.5 feet and deeper:

“The upper unit consists of silty gravels and generally had a loose to compact consistency (per Standard Penetration blow counts) and extends below the pavement and aggregate sections to elev. 92.3± (7.5±ft depth). The lower unit consists of silty gravels with cobbles and local boulders. The unit generally had a compact to very dense consistency (per Standard Penetration blow counts) and extends from below the upper unit of alluvium (elev. 92.3±) to the top of the rock unit. Boulder size material, up to 2±ft in diameter, was encountered in boring B-1; and up to 1±ft in diameter in boring B-2…Larger boulders up to 4 to 5-ft in diameter were also observed at ground surface and in the slopes surrounding the proposed bridge location.”

Figure 8. USFS Pebble Count- Conner Creek


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Comparative Watershed Assessment A similar project was completed in Soldier Creek, an adjacent watershed, in 2005 that provides comparative analysis of hydrologic impacts to Conner Creek. In 2005, the DOT and 5C replaced two crossings within the lower reach of Soldier Creek on Evans Bar and Dutch Creek Roads. In 2009, the Forest Service replaced a culvert barrier on Soldier Creek (upstream). The two crossings on Soldier Creek that were replaced by DOT in 2005 are approximately the same distance apart as Crossing #1 and #2 on Conner Creek. The watershed characteristics for both are also relatively similar as shown in Table 5 below. The pre-project conditions at both Soldier Creek crossings were undersized and overtopped on a 7-year recurrence interval (Dutch Creek Road) and a 6-year recurrence interval (Evans Bar Road). Crossing #2 overtops on a 43-year interval and Crossing #1 overtops on an 18-year interval but the crossings backwater on the approximately 15-year flow.

Table 5. Comparative Watershed Data

Existing Conditions Conner Creek Soldier Creek

Watershed Area 3,243 acres 4,580 acres Watershed Area Ratio 1.41:1 0.71:1

High Point Elevation 5,707’ 5,556’

Low Point Elevation 1,440’ 1,500’

Elevation Difference 4,267’ 4,113’

Main Stem Channel Perennial Length

4.8 Miles 5.0 Miles

Geology North Fork Terrane W/Diabase

North Fork Terrane

Q100 1,160 cfs 1,800 cfs Q100 Ratio 1.55:1 0.65:1

Mean Annual Precipitation 37” 40”

Given that the watersheds are at similar elevations, have comparable annual precipitation and principally vary only by watershed area, the Q100 flows in the Conner Creek and Solider Creek subwatersheds are very similar. Both originate on the Hayfork Divide. The Soldier Creek watershed is located five miles southeast of Conner Creek and is geologically similar, though there is a large diabase intrusion transecting the central portion of the Conner Creek watershed. Conner Creek has a somewhat steeper gradient but bedload strata sizes are similar. The two County Soldier Creek crossings have been monitored for evidence of cutbank and slope erosion since their installation in 2005 with no significant rill or gully erosion observed at either crossing. In December 2005/January 2006 there was a large enough storm to declare state and federal disasters for road damage throughout Northern California. Neither of the Soldier Creek crossings showed any adverse response to the 2006 high flows. Post-project channel changes at Soldier Creek have been minimal and are being studied as part of a nation-wide Forest Service assessment of channel function following restoration activities. The study, being conducted by Dr. Margaret Lang of Humboldt State University, will provide information on geomorphic channel response at crossings where undersized culverts have been remediated with active channel design structures. Based on the comparative watershed analysis with Soldier Creek, the design for the Conner Creek crossings should not result in significantly different bedload responses.


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III. Erosion/Water Quality Risk and Effects Analysis

Implementation of the project would meet long-term benefits for salmonid restoration outlined by the regulatory agencies, NWFP and Aquatic Conservation Strategy Objectives and the Forest Plan goals and objectives as described in Section IV below. In determining the appropriate level of NEPA review, the thresholds of significance for the use of NEPA Categorical Exclusions have been established for hydrologic impacts as follows: 1. Floodplains: Executive Order 11988 provides direction to avoid adverse impacts associated with the

occupancy and modification of floodplains. Floodplains are defined by this order as “…the lowland and relatively flat areas adjoining inland and coastal waters including flood-prone areas of offshore islands, including at a minimum that area subject to a 1% (100-year recurrence) or greater chance of flooding in any one year.” Relative to floodplain impacts, the project would result in meeting the goal of restoring floodplain function at both crossings by replacing the existing culverts with structures sized to convey the 100-year flow. The existing crossings convey flows and associated bedload and debris during smaller storm events before upstream backwatering begins. Flows in exceedance of the 15-year flow backwater the crossing inlets, resulting in debris plugging and deposition of larger sized particles that artificially alter the upstream floodplain. The crossings overtop at the 18-year (#1) and 43-year (#2) recurrence interval and the significant difference between flows is primarily due to the larger roadfill prism at Crossing #2. The road prism (~dam) allows for a significant reservoir to form upstream compared to the minimal fill and reservoir capability at Crossing #1. The project is consistent with the direction set forth in Executive Order 11988. No extraordinary circumstances with respect to floodplains would be created by the project. There are no short-term adverse effects to floodplains related to construction. Work within the floodplain will be done in accordance with BMPs. In the long term, considerable floodplain functionality would be restored.

2. Wetlands: Executive Order 11990 was promulgated to avoid adverse impacts associated with destruction or modification of wetlands. Wetlands are defined by this order as “…areas inundated by surface or ground water with a frequency sufficient to support, and under normal circumstances does or would support, a prevalence of vegetative or aquatic life that requires saturated or seasonally saturated soil conditions for growth and reproduction. Wetlands generally include swamps, marshes, bogs and similar areas such as sloughs, potholes, wet meadows, river overflows, mud flats and natural ponds.”

The project would not alter or affect wetland habitats as there are no wetland habitats within the project area. Therefore, no extraordinary circumstances with respect to wetlands would be created by the project.

3. Municipal watersheds: Municipal watersheds are defined in FSM 2542.05 as “A watershed that

serves a public water system as defined in the Safe Drinking Water Act of 1974, as amended (42 U.S.C. §§ 300f, et seq.); or as defined in state safe drinking water statutes or regulations.”

There are no municipal water systems downstream of the project as defined in FSM 2542.05. Therefore, no extraordinary circumstances with respect to municipal watersheds would be created by the project.

While the project would have long-term benefits, an assessment of potential effects of the short-term impacts must be considered and evaluated to determine the appropriate level of environmental evaluation


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and to develop resource protection measures that reduce the potential impact(s). If the hydrologic analysis for a project determines that there are: a) no, or minimal, short-term adverse impacts of a project to hydrologic resources and water quality; b) that the project would not result in extraordinary circumstances to the defined resource values [FSH 1909.15 Chapter 30.4; 36 CFR 220.6(b)]; and c) that the project would result in long-term benefits to hydrologic resources, then the project would not have extraordinary impacts to floodplains, wetlands or municipal water sources, as described above.

Project Related Erosion Risks The current condition assessment (USFS, 2008) shows an increasing trend for potential culvert plugging and overtopping of the roads at both crossings. The increasing trend is directly related to the short to mid-term increases in peak discharge and bedload and debris movement within the upper 41% of the watershed; due to low to moderate burn intensities during the 2008 Eagle Fire where high intensity, stand-replacing fires occurred along some of the ridges in the watershed (USFS, 2008). Prior to the Eagle Fire, both crossings had moderate to moderately high plug potential due to being undersized for high flows and the offset and steel ramp baffles (Taylor, 2002).

Crossing #2 has the greatest potential for significant sediment delivery from either a roadfill failure or project construction activities. A roadfill failure that could result from culvert plugging, headwall and road overtopping from high flows and associated debris has the potential to deliver between 750-2000 cubic yards of sediment to the downstream reached. Subsequent sediment delivery from failure-related scour, channel downcutting and/or bank erosion are not factored into this estimate. During construction at Crossing #2, an estimated 740yd3 of fill material would be excavated and endhauled to an existing open, flat storage area near the intersection of Conner Creek and Red Hill Roads. There is potential for some material to drift down slope and be deposited in the stream channel during excavation. There is also potential for the newly placed fill slopes to erode and deposit sediment due to rainfall impacts, slumps or rill and gully erosion. All three types of potential sediment delivery (drift, slump or rill) are typical risks associated with roadfill slopes and stream crossing replacement/modification activities. Development and adherence to effective resource protection measures and design criteria are key in reducing if not preventing potential sediment delivery. Refer to Section V for a discussion of the measures taken to prevent these types of impacts. Crossing #1 has a significantly lower potential for pre-, during- and post-construction related sediment delivery. The existing concrete box culvert will remain in place during excavation of the new footing and abutment structures, protecting the stream channel from excavation-related sediment. Minimal upstream channel excavation is required to restore the natural channel gradient. At both crossings, engineered stream channel material would be installed and jetted (to seal voids) within the new crossing reach(es) and outlet pool(s). At both crossings, the channel would be de-watered during this process, a recycled water system would be used during jetting and any excess water would be pumped out of the floodplain and discharged in a location where it would not affect water quality. Removal of the corrugated metal pipe and concrete box culvert at both crossings (and all construction work associated with the project) would be done in accordance with the 5C Program’s “A Water Quality and Stream Habitat Protection Manual for County Road Maintenance in Northwestern California Watersheds” (or Roads Manual) BMPs. Both stream channels will be dewatered at the time of removal. Refer to Section V for a discussion of Roads Manual BMPs and Resource Protection Measures that will minimize the risk of significant surface erosion and reduce if not prevent sediment delivery to the stream channel.

Project Related Water Quality Risks The North Coast Regional Water Quality Control Board (NCRWQCB) implements both the federal Clean Water Act and state Porter-Cologne Water Quality Control Act for waters within their area of jurisdiction (see Section IV- Regulatory Environment). The 2007 Water Quality Control Plan (Basin Plan) for the North Coast Region identifies beneficial uses and sets water quality objectives for waters within the Trinity River Hydrologic Unit. The NCRWQCB adopted water quality objectives in the Basin Plan for the reasonable protection of beneficial uses and prevention of nuisance from activities on National Forest


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System lands. These objectives are consistent with the state and federal anti-degradation policy and include suspended material; settleable material; oil and grease; sediment; turbidity; pH; temperature; toxicity; and chemical constituents. Trinity County DOT fulfills these obligations through proper installation, operation and maintenance of state or federally certified Best Management Practices described in the Roads Manual. The Forest Service meets its obligation through the 2000 Forest Service Region 5 BMP handbook (USDA Forest Service, 2000). As noted in Section V, the project would be conducted in compliance with the Roads Manual which includes project type-specific BMPs to maintain water quality during and after construction that are similar to BMPs in the Forest Service BMP handbook. In addition to the Basin Plan objectives, the US EPA prepared an Allocation Plan for sediment in the mainstem Trinity River in 2000 (EPA, 2001) that included target indicators of watershed recovery as shown below in Table 3-3 of the TMDL. Removal of undersized stream crossings is one of the targets identified to restore cold-water fisheries beneficial use of the Trinity River (see Table 3-3 from the TMDL on the following page).

The existing crossings are undersized for conveyance of storm flows, bedload and/or debris during large storm events and prevent upstream migration of fish. The 2008 Eagle Fire has increased the risk of crossing failure, primarily due to the expected higher peak storm discharges anticipated during the watershed recovery period. Following the Eagle Fire, the Equivalent Road Acres (ERA) analysis of fire impacts on watershed condition changed Conner Creek’s Condition Class from I to Condition Class II. Condition Class II watersheds have a moderate risk of adverse cumulative effects from project activities. The HRA (Hydrological Resource Assessment) modeling predicted a peak increase in 10-year recurrent storms runoff rates of 1.5-1.8 times compared to pre-fire conditions in the Conner Creek watershed (USFS, 2008). Portions of the soils severely burned in the fire have developed hydrophobic conditions that result in increased runoff rates. Tree root degradation and decay from stand mortality will continue to occur over the next 20 to 30 years; and new tree and shrub root growth will not fully replace the soil stabilization factors of lost roots during this time. Roots are an important contributor to providing soil support and transpiring water from the soil column and the greatest impact of lost tree root strength to soil stability occurs approximately 10 years after tree mortality (Zeimer, 1981).


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Threats to habitat quality and species abundance and diversity may be exacerbated where human-caused disturbance has previously fragmented and compromised aquatic habitat (Dunham et al, 2007, Gresswell 1999). Undersized drainage system failure, erosion and mass wasting failure of roadfill and stream crossings can occur following fires (Coe, 2006). Biologically, the existing crossing structures prevent upstream migration of anadromous salmonids and other aquatic vertebrates/invertebrates (refer to the Conner Creek Fish Passage Improvement Project Fisheries Biological Assessment and Evaluation). Empirical evidence from completed 5C projects shows terrestrial wildlife mortality (deer, bear, raccoon) on roads near barrier removal projects has significantly declined, notably where undersized perched


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culverts have been replaced with bridges or embedded culvert structures. The 10-foot diameter culvert at Crossing #2 acts as a choke point for large debris that cannot be transported downstream and the box culvert at Crossing #1 has been documented to trap debris within the offset baffles. The new crossings will convey the 100-year recurrence interval flow and provide for transport of bedload and debris more efficiently; which is critical due to the upslope loss of vegetation and wood structures as a result of the Eagle Fire. Empirical observations of a similar sized watershed (West Weaver Creek) following the 2001 Oregon Fire noted extensive sediment and wood movement into and through a similar arched crossing on Oregon Street in the Weaverville area within the first decade following the fire (Figure 9).

The Forest Plan establishes Forest Goals to “provide for the protection, maintenance, and improvement of wild trout and salmon habitat,” to “maintain or improve water quality and quantity to meet fish habitat requirements and domestic use needs (Forest Plan, page 4-4),” and to “maintain water quality to meet or exceed applicable standards and regulations (Forest Plan, page 4-6).” These Goals, combined with the 5C and Trinity County fisheries and water quality enhancement programs over the past decade, meet other state and federal objectives including the Clean Water Act Trinity River TMDL Allocation Plan, California Coho Recovery Strategy, and the Klamath Mountain Steelhead recovery direction cited by the National Marine Fisheries Service (NMFS) in the Federal Register (April 4, 2001 Volume 66).

Figure 9. LWD transport through West Weaver Creek crossing following a

high intensity fire in the upper watershed.

In addition, the Standards and Guidelines issued with the Record of Decision for the 1994 NWFP incorporate the Aquatic Conservation Strategy (ACS) Objectives that apply to Riparian Reserves and Key Watersheds (Appendix B). The ACS emphasizes maintenance and restoration of the physical and biological integrity of aquatic and riparian habitat. Anthropogenic barriers to fish passage and bedload and debris transport combined with landscape-scale wildfire influences degrade aquatic ecosystems beyond the range of natural variability, and hence are at odds with the ACS. The purpose and need for the project meets with the Forest Plan’s water quality and beneficial uses goals, such as providing for the protection and improvement of wild trout and salmon habitat, improving water quality to meet fish habitat requirements and maintaining water quality to meet or exceed applicable standards and regulations. Replacing and modifying the crossings


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will not only improve the fish passage conditions but will also improve flow capacities, thereby reducing the maintenance requirements and emergency response expenditures for Trinity County DOT. The project would not change the current watershed condition class or ERA levels and will improve hydraulic function at both crossings, allowing for improved passage of salmonids at higher flows. Trees proposed for removal from the roadfill at Crossing #2 would not have provided LWD to the downstream channel because they are on the upstream side of the culvert and would not pass through the pipe. Large LWD that is mobilized from upstream would also not pass through the existing culvert, and would likely have to removed from upstream to prevent jams, plugging and potential crossing failure, with no habitat benefits. After completion of the project, there will be an improved opportunity for conveying LWD through the new crossing with subsequent benefits to salmonid habitat lower in the system. Since the trees can be removed from the roadfill with intact root wads, there is an opportunity to utilize the material in channel habitat improvement projects in the future. Removal of vegetation on the existing roadfill at Crossing #2 would not measurably impact water temperature. The channel flows from west to east with two forested, parallel ridges that provide 50 to 70% canopy to the stream. None of the trees proposed for removal currently provide significant shade that is not already provided by the overhead and adjacent road fill. The net change in leaf litter from removing the trees is negligible. There would be an insignificant loss of litter fall to the stream from removal of the trees. The majority of trees proposed for removal are too small (<1 to 6”) to offer significant amounts of leaf biomass and much of the existing fallen leaf litter lands on the road fill rather in the creek. The project includes replanting of native trees on the replaced fill, including trees in the 1 to 2-inch diameter class to promote rapid revegetation. The mainstem Trinity River (4th-field HUC) is located approximately 1 mile east of the project area and contains Chinook and coho salmon and steelhead trout. There would be no direct effects to anadromous fish at the 4th- or 5th-field watershed scale. Indirect effects include short-term increases in substrate mobility and turbidity from coarse and fine sediment transport and these impacts would be immeasurable at the 4th- and 5th-field scale. Effects at the 7th-field watershed and project site scale are described above.

IV. Regulatory Environment

The following provisions of law, regulation and policy provide direction for the conclusions in this report regarding implementation of the Conner Creek Fish Passage Improvement Project from the perspective of watershed function and protection. Federal Endangered Species Act (1972): The coho salmon within the Southern Oregon Northern California Coast evolutionarily significant unit (SONCC ESU) was listed as a Threatened species under the Endangered Species Act in 1997. The project would improve habitat access for federally threatened coho salmon4 and the Klamath Mountains Province Distinct Population Segment of steelhead (KMP DPS),5 a Forest Service sensitive species. The proposed action affirms the Klamath Mountain Steelhead recovery direction cited by the National Marine Fisheries Service (NMFS) in the Federal Register: April 4, 2001 Volume 66: “NMFS intends to capitalize on the significant efforts being made by all entities, from large-scale transboundary actions adopted via the Northwest Forest Plan and Klamath and Trinity Rivers Restoration Acts to more localized efforts like those implemented by the Five Counties Salmon

4 NOAA Fisheries Coho Recovery Planning: www.swr.noaa.gov/recovery/Coho_SONCCC.htm 5 NOAA Fisheries Steelhead Information: www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Steelhead/STKMP.cfm

http://www.swr.noaa.gov/recovery/Coho_SONCCC.htm

http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Steelhead/STKMP.cfm

http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Steelhead/STKMP.cfm


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Conservation Program and Scott River Watershed Council. These efforts, coupled with ESA protective regulations for listed coho salmon, will likely improve conditions for KMP steelhead as well.” Magnuson-Stevens Reauthorization Act Klamath River Coho Salmon Recovery Plan (2007): This plan analyzes and makes recommendations regarding the recovery of the threatened Southern Oregon/Northern California Coast (SONCC) coho salmon evolutionarily significant unit (ESU) and hydrologic units (HUs); areas (HAs); and sub-areas (HSAs) within the range of the SONCC ESU. It incorporates recommendations from the Recovery Strategy for California Coho Salmon prepared by the California Department of Fish and Game in 2004. Executive Order 11998 (1977); Floodplain Management: This Executive Order requires all Federal agencies to take actions to reduce the risk of flood loss, restore and preserve the natural and beneficial values in floodplains, and minimize the impacts of floods on human safety, health and welfare. Federal Clean Water Act: Key sections of this law and related amendments include: Section 208 requiring states to develop and use Best Management Practices (BMPs) for managing non-point source pollution; Section 303(d) requiring that waterbodies that are repeatedly out of compliance with the applicable water quality standards be subject to a Total Maximum Daily Load or TMDL; and Section 404 regulates discharge of dredged or fill material into navigable waters (waters of the U.S). The project is included under the Army Corps of Engineers (ACOE) Regional General Permit (RGP) No. 12 for those projects funded under the California Department of Fish and Game’s (CDFG) Fisheries Restoration Grant Program (FRGP). Under Section 401 of the Clean Water Act (33 U.S.C. Section 1341), an applicant for a Corps permit must first obtain a State water quality certification before a Corps permit may be issued. Water quality certification is issued on an annual basis. CDFG has established an annual certification and project reporting procedure with the State Water Resources Control Board. Projects scheduled for the upcoming year are submitted, in addition to annual reports listing the previous year’s projects. The 2011 Section 401 Water Quality Certification will be applied according to the established procedure. No Corps permit will be granted until the applicant obtains the required water quality certification. The Corps may assume a waiver of water quality certification if the State fails or refuses to act on a valid request for certification within 60 days after the receipt of a valid request, unless the ACOE District Engineer determines a shorter or longer period is reasonable for the State to act. An evaluation of the proposed activities under the current RGP 12, and their impact, includes application of the guidelines promulgated by the Administrator of the Environmental Protection Agency under Section 404(b)(1) of the Clean Water Act (33 U.S.C. Section 1344(b)). As such, the project will not be enrolled under the Forest Service waiver of discharge requirements. The proposed project is located on a County road where the County has an approved easement with the United States Department of Agriculture for maintaining the road and associated right of way areas and the primary function of the Forest Service in this project is as a contributing partner for project funding, requiring full compliance with the NEPA. The Forest Service waiver is limited to timber sale activities and does not apply to the proposed action. The project will comply with Section 401 requirements that are provided under the RGP No. 12 and the CDFG water quality certification. The time limit for completing the work under the RGP No. 12 is December 1, 2015. Clean Water Act (CWA), Porter-Cologne, Basin Plan Per the CWA, Porter-Cologne and the Management Agency Agreement (MMA) with the State Water Resources Control Board, the Forest Service accepts responsibility as the water quality management agency for National Forest lands in California. Those responsibilities include providing for review of project planning by the State, and implementation of the mutually agreed-on Best Management Practices developed by the Forest Service to meet the regulatory requirements of the CWA, the EPA and the MAA (USDA Forest Service, 2000). The MAA gives the State broad authority to administer the CWA and Porter-Cologne, and to regulate ground-disturbing activities that have the potential to affect water quality and beneficial uses of water. The State may issue notices of violation, cease and desist orders, cleanup


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and abatement orders and impose fines and monitoring requirements when water quality is threatened or degraded by activities of the Forest Service or under Forest Service jurisdiction. Because Conner Creek is 303(d) listed as an impaired water body for sediment and temperature, any project disturbance that may deliver sediment or elevate stream temperatures is subject to regulatory scrutiny and BMP application sufficient to prevent sediment delivery or increased temperatures from affecting beneficial uses of water is required. BMPs have therefore been selected to reduce or eliminate the threat of water quality impairment from the proposed action.

Trinity River Sediment Total Maximum Daily Load Allocation Plan: The Trinity River was designated as sediment impaired under Section 303(d) of the Clean Water Act and in 2000 the TMDL was completed (EPA, 2000). The project will implement the following Instream and Watershed Indicators listed in Table 3.3 Sediment Indicators and Targets of the Trinity River Sediment Total Maximum Daily Load:

• Increase Large Wood Debris Target: The project will meet this target by allowing transport of LWD that cannot currently be routed through one or both of the existing crossings. The new crossings will convey the 100-year recurrence interval flow and provide improved transport for LWD as described above.

• Reduce Diversion Potential & Stream Crossing Failure Potential: The project will allow conveyance of the 100-year recurrence interval flow and address short-term and mid-term increased peak discharge potential resulting from the Eagle Fire. Larger culverts/crossings will also reduce the potential for culvert plugging at the inlet with LWD and subsequent ponding of water, diversion and culver failure.

• Restore Hydrologic Connectivity: The existing culverts do not allow for natural routing of bedload and debris. The existing culverts backwater at less than the 18- and 43-year flood flows and the stream begins dropping bedload under those conditions. The project will allow for natural routing of flows and bedload transport during these higher flows.

• Northwest Forest Plan Aquatic Conservation Strategy (ACS): For details on how the project will implement Riparian Reserves, the Aquatic Conservation Strategy Objectives and Riparian Management (Prescription 9) objectives, refer to the Fisheries Biological Assessment and Biological Evaluation and Appendix B of this document.

National Environmental Policy Act (1969) and CEQ’s Implementing Regulations (40 CFR 1500): The National Environmental Policy Act (NEPA) is the basic national charter for protection of the environment. The Council on Environmental Quality (CEQ) was established by the NEPA (Act) to interpret and implement the provisions of the Act as they apply to Federal agencies. The Act requires federal agencies to perform environmental analysis of proposed activities, in order to assess the nature, characteristics and significance of the effects of a proposed action and its alternatives on the human environment.

• Forest Service Manual 1950: The Forest Service Manual, Chapter 1950 (FSM 1950) – Environmental Policies and Procedures sets forth Forest Service management objectives, policy and responsibilities for meeting the requirements of NEPA.

• Forest Service Handbook 1909.15: The Forest Service Environmental Policies and Procedures Handbook (FSH 1909.15) provides procedural direction for implementing NEPA, the CEQ regulations, and USDA NEPA policies and procedures. Chapter 30 contains the documentation and process requirements for categorical exclusions, which the Conner Creek Fish Passage Improvement Project is promulgated under. Section 30.3 directs that “a proposed action may be categorically excluded from further analysis and documentation in an EIS or EA only if there are no extraordinary circumstances related to the proposed action.” This section also describes “resource conditions that should be considered in determining whether extraordinary


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circumstances related to a proposed action warrant further analysis and documentation in an EA or an EIS…”, including “flood plains, wetlands, or municipal watersheds.”

• Water Quality Control Plan for the North Coast Region (Basin Plan) (2007): The Basin Plan is the guiding document regulating water quality within the North Coast Region. It is designed to preserve and enhance water quality and to protect beneficial uses of water. Each regional water board, in this case the North Coast Regional Water Quality Control Board (NCRWQCB), identifies “impaired waterbodies” [the 303(d) list] that do not meet the standards set forth in the Basin Plan and may not fully support beneficial uses of water. Each water board then develops pollution reduction plans establishing Total Maximum Daily Loads (TMDLs) to improve and restore water quality to meet Basin Plan standards. TMDLs established by the EPA are in place for reduction of sediment loads in the Trinity River & Conner Creek watersheds (EPA 1998). Implementation and monitoring plans are to be developed by the NCRWQCB.

NEPA, FSH 1909.15, Executive Order 11998 The project is categorically excluded from further NEPA analysis under Category 7 [36 CFR 220.6(e)(7)] as the project description and design meets the terms of this category. Per the conditions of categorical exclusion, it must be demonstrated that there are no extraordinary circumstances that affect a number of resource conditions, including flood plains, wetlands, or municipal watersheds and “the mere presence of one or more of these resource conditions does not preclude use of a categorical exclusion (CE). It is the existence of a cause-effect relationship between a proposed action and the potential effect on these resource conditions and if such a relationship exists, the degree of the potential effect of a proposed action on these resource conditions that determine whether extraordinary circumstances exist.” [FSH 1909.15_30.4; 36 CFR 220.6(b)]. As described above, the Conner Creek Fish Passage Improvement Project will restore a portion of the 100-year floodplain and project design standards and BMPs would reduce or eliminate the risk of negative effects to aquatic and riparian resources and water quality. Based on the evidence of minimal effects from past similar stream crossing replacement activities and the protection from resource damage that would be provided by project design standards, resource protection measures and BMPs, no extraordinary circumstances with respect to floodplains, wetlands, or municipal watersheds are present that would prevent the project from categorical exclusion from further NEPA documentation. Northwest Forest Plan Standards and Guides, Shasta-Trinity Forest Plan (Riparian Reserves, Watershed Analysis, ACS Objectives) The NWFP and the Forest Plan affect the proposed Conner Creek Fish Passage Improvement Project through the established standards and guides and management direction. The land allocations established by the NWFP ROD define Riparian Reserves with specified interim widths adjacent to waterbodies. For perennial fish-bearing streams, the Riparian Reserve width consists of the stream and the area on each side of the stream extending from the edges of the active stream channel to the top of the inner gorge, or to the outer edges of the 100-year floodplain, or to the outer edges of riparian vegetation, or to a distance equal to the height of two site-potential trees, or 300 feet slope distance (600 feet total, including both sides of the stream channel), whichever is greatest. Riparian Reserve widths may be adjusted during watershed analysis, although the intent was to adjust widths for intermittent and ephemeral streams, with perennial Riparian Reserve widths in most cases to remain constant. The entire Conner Creek Fish Passage Improvement Project area falls within Riparian Reserves with exception of the one-acre flat staging area near the intersection of Conner Creek and Red hill Roads. Consequently, ACS Objectives must be met for the proposed project activities to proceed. ACS Objectives direct the Forest to maintain and restore a variety of watershed, stream and riparian features, processes and functions and the standards and guides for Riparian Reserves state that “As a general rule, standards and guidelines for Riparian Reserves prohibit or regulate activities in Riparian Reserves that retard or prevent attainment of the Aquatic Conservation Strategy Objectives.”


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Work within the Riparian Reserves is allowed and resource protection measures and design criteria that meet with the ACS Objectives would be utilized. These measures include directional felling of trees when completing vegetation removal, utilizing oil absorbing booms, onsite spill prevention equipment, utilizing silt fencing and straw bales/waddles for erosion control, installing temporary stream diversions through the construction reaches at both crossings and native species revegetation plans as described in Section V below. These resource protection measures would result in minimal disturbance to riparian vegetation and would not result in bank destabilization or increasing the erosion hazard in the project or action area Riparian Reserves. Shasta-Trinity National Forest Plan – Forest-wide Goals and Standards & Guidelines: The project meets the following Forest Plan goals:

• Provide for the protection, maintenance and improvement of wild trout and salmon habitat (page 4-4);

• Maintain or improve water quality and quantity to meet fish habitat requirements and domestic use needs (page 4-6);

• Maintain water quality to meet or exceed applicable standards and regulations (page 4-6). The project will adhere to the following Forest Plan Standards & Guidelines:

• Coordinate road improvement and maintenance projects with other Forests, State and local agencies, and cooperators, as needed (page 4-17).

• Coordinate rehabilitation and enhancement projects with cooperating agencies involved in the Model Steelhead Stream Demonstration Project Plan and the Trinity River Basin Fish and Wildlife Management Program (page 4-18).

• Implement Best Management Practices (BMPs) for protection or improvement of water quality, as described in “Water Quality Management for National Forest System Lands in California” (2000) for applicable management activities. Determine specific practices or techniques during project level planning using information obtained from on-site soil, water and geology investigations (page 4-25).

• Maintain and/or enhance habitat for threatened, endangered and sensitive species consistent with individual species recovery plans (page 4-30).

Complete management direction, management prescriptions and standards and guidelines for the project’s management area and land allocations can be found in the appropriate sections of the Forest Plan (Forest-wide, page 4-23; Riparian Reserves, page 4-53; AMA, page 4-69; Trinity River Management Area, page 4-141, USDA-FS 1995.

V. Resource Protection Measures and Design Criteria

The project includes specific resource design criteria, protection measures and best management practices (BMPs) to minimize effects to hydrologic function, fish, aquatic and terrestrial wildlife, plants, water quality and soils. Activities that could result in potential negative impacts include aquatic species relocation, construction within the stream channel (introduction of pollutants/sediment and species impacts), minor vegetation removal, introduction of minor amounts of fine sediment, short-term duration noise above ambient levels and potential introduction and/or spread of noxious weed species. The BMPs for replacing a stream crossing, sediment prevention, aquatic species relocation, erosion control and revegetation listed in the Roads Manual would be adhered to throughout project planning and implementation. A full copy of the Manual, or specific chapters/appendices is available at: www.5counties.org/Projects/FinalGeneralProjectPages/RoadsManual800.htm.


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Minor amounts of vegetation would be removed in order to excavate the existing culverts at both crossings, but revegetation efforts would mitigate the removal. Excavation of the roadfill at Crossing #2 is the highest level of disturbance associated with the project and upstream/downstream impacts to natural channel banks would be limited. It is estimated that no more than 10 feet of the upstream/downstream stream banks at both crossings would be disturbed, including tree/shrub removal. It is anticipated that only trees within the road fill prism and immediately adjacent to the existing culvert would be removed at this site. It is further anticipated that minimal impact to riparian trees would occur at Crossing #1. At most, three alders located downstream of the crossing may have to be trimmed or removed if retention does not allow for vehicle safety. Where trees need to be felled along the stream banks, directional felling would be used to minimize disturbance to the stream banks. “A Water Quality and Stream Habitat Protection Manual for County Road Maintenance in Northwestern California Watersheds” (Roads Manual): The Trinity County Board of Supervisors adopted the Roads Manual in 2004 that lists Best Management Practices (BMP) for County road maintenance. In 2007 the National Marine Fisheries Service incorporated the Roads Manual into Limit 10, Section 4(d) of the Federal Endangered Species Act for incidental take of coho salmon. Appendix B of the Roads Manual lists all BMPs and select BMPs are included in Appendix A of this document. The BMPs are prescribed on a site-specific basis for applicability and effectiveness during various routine maintenance activities. This project implements all of the relevant BMPs including the following:

• 4.B.5. Replacing the existing culvert with a bridge, a natural bottom system, or a properly designed and installed culvert is desirable when a high jump and/or the velocity of the water in a culvert may result in a probable fish migration barrier (usually less than 1 foot).

• 4.B.7. For pipes that are to be replaced, design for anadromous fish passage as per the most recent NMFS and DFG guidelines.

• 4.B.8. Minimize disturbance of riparian vegetation during culvert improvement and repair operations and replace lost plants if needed to provide critical shade cover.

• 4.C.1. Size crossings to handle most probable 100-year flood flows and associated debris and bedloads, given the watershed and specific conditions present in each county. Site-specific constraints may warrant a different standard.

• 4.C.2. See the County Engineer for determining the correct culvert diameter and length for a given stream crossing to meet hydraulic capacity requirements for flood risk and channel stability.

• 4.C.3. Refer to the latest NMFS and DFG fish passage guidelines and criteria to size replacement culverts for fish passage in anadromous fish-bearing streams. Consult with NMFS and DFG early in the design process.

Water Quality Management for National Forest System Lands in California – Best Management Practices By conforming to the resource protection measures, Roads Manual BMPs and other design criteria discussed in this section, the project would also be in conformance with the BMPs established in the Forest Service Region 5 BMP handbook (USDA Forest service, 2000). The specific BMPs that apply and would be followed are:

• Limiting the Operating Period of Project Activities: 1-5 • Erosion Prevention and Control Measures During Project Operations: 1-13 • Revegetation of Areas Disturbed by Harvest Activities: 1-15 • Streamcourse and Aquatic Protection: 1-19 • Erosion Control Structure Maintenance: 1-20


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• General Guidelines for the Location and Design of Roads: 2-1 • Erosion Control Plan: 2-2 • Timing of Construction Activities: 2-3 • Stabilization of Road Slope Surfaces and Spoil Disposal Areas: 2-4 • Road Slope Stabilization Construction Practices: 2-5 • Timely Erosion Control Measures on Incomplete Roads & Stream Crossing Projects: 2-9 • Construction of Stable Embankments (Fills): 2-10) • Control of Sidecast Material During Construction and Maintenance: 2-11 • Servicing and Refueling of Equipment: 2-12 • Control of Construction and Maintenance Activities Adjacent to SMZs: 2-13 • Controlling In-Channel Excavation: 2-14 • 2-15 Diversion of Flows Around Construction Sites: 2-15 • Bridge and Culvert Installation: 2-17 • Disposal of Right-of-Way and Roadside Debris: 2-19 • Specifying Riprap Composition: 2-20 • Conduct Floodplain Hazard Analysis and Evaluation: 7-2

General Resource Protection Measures

Resource protection measures and design criteria developed to protect and enhance aquatic habitat conditions and avoid or reduce adverse effects to federally listed species and Forest Service Sensitive fish and wildlife species are included in the fisheries and wildlife BA/BE documents. A summary of some of those measures that relate to reducing soil disturbance, impacts to vegetation and the spread of noxious weeds are included below:

1. There will be no water drafting from streams or the Trinity River. 2. The period of operations shall be between May 15 and October 15. Operations may continue

beyond October 15 with the approval of the Department of Fish and Game and the USFS District Ranger with consultation with the project hydrologist and/or fisheries biologist, under conditions where no resource damage related to wet weather are likely to occur.

3. All applicable BMPs for Stream Crossing Replacement listed in the Roads Manual will be adhered to throughout construction.

4. Ground disturbing activity (heavy equipment use) will not occur during wet weather conditions. 5. Temporary detours that consist of Bailey bridges or similar structures (that do not require

placement of fill material within the stream crossings to construct detour roads) will be used. 6. Permanent and temporary spoils will be stored in a manner to prevent sediment delivery to any

watercourse during and after project construction. All spoils material will be removed from the construction area prior to October 15 and stored at a Trinity County DOT yard and/or suitable and approved privately owned sites.

7. All disturbed areas will be revegetated with native grass, forb and tree species immediately following project construction, including the equipment storage and staging areas, disturbed stream banks, the access road upstream of Crossing #2 and spoils disposal sites. Equipment cleaning will be required to reduce the potential for introduction of noxious weeds into the project area.

8. The project does not include new road construction or decommissioning nor does it include staging area construction as existing open flat areas will be used for staging and material storage.


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Construction

Project construction will be conducted by DOT road crews who have Roads Manual training and prior experience constructing fish passage improvement projects. Construction is currently scheduled for May 15 through October 15th of the year of construction and will consist of the following general elements:6

1. Pre-, during and post-project photo and water quality monitoring; 2. Pre-construction meeting where the overall project plan, WPCP, Excavation Safety Plan and

applicable Roads Manual BMPs will be discussed; 3. Aquatic species relocation; 4. Vegetation removal; 5. Temporary detour installation; 6. Stream dewatering/temporary diversion installation; 7. Construction; 8. Erosion control and revegetation.

Spill Prevention

DOT shall prepare a spill prevention plan that details precautionary, preventative and spill response measures sufficient to prevent resource damage from any fuels, lubricants or hydraulic fluids used or stored on site. The plan shall include provisions for: 1) safely refueling equipment outside the Riparian Reserve; 2) storing any fuels, lubricants or hydraulic fluids offsite or outside the Riparian Reserve and contained to prevent accidental spillage if containers are compromised; 3) emergency response measures adequate to rapidly contain and clean up any spills in a timely manner to prevent dispersal and contamination of soils or water resources, including onsite availability of a spill kit containing absorbent pads, booms and a leak-proof container for storing contaminated spill cleanup materials; and 4) a reporting requirement that the Forest Service and any necessary emergency responders be notified immediately of any spills, with the stipulation that the spill and all response measures be thoroughly documented and delivered as soon as possible to the District Ranger. The Forest Service and other regulatory agencies may order cessation of operations, cleanup and abatement, and/or fines or other punitive measures if hazardous spills occur.

1. Self contained sewage and grey water facilities will be present and the project operator will ensure and demonstrate that the sewage containment system is in good operating condition.

2. Temporary concrete wash-out facilities, consisting of a depression or pool constructed of straw bales or sand bags lined with plastic, will be constructed at the flat staging areas away from the stream channel. Accumulated concrete waste will be disposed of, along with the plastic liner, in the County landfill.

Spoils and Fill Material

1. The existing crossings will remain in place until all fill material that could fall into the channel area is excavated.

2. Excavated fill will not be stored at, or near, the crossing sites but rather will be stored approximately 300 feet from the channel in a construction staging/storage area and outside of the 100-year floodplain of any stream.

3. If excavated material is to be reused during construction, it will be stored at the existing flat staging areas to prevent sediment transport towards the stream.

4. All permanent and temporary spoils storage locations and stabilization methods will adhere to the Roads Manual BMPs.

6 Not all elements are described here, only those relative to soil disturbance and vegetation are included.


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5. Fill that is stored temporarily will be partially compacted in 1-foot lifts by wheel or track rolling equipment. Water will be required if the soil is not sufficiently wet to partially compact.

6. Stored fill will be covered with plastic tarps sufficient to prevent any rain splash erosion and secured to prevent release in wind at the end of the work day when any of the following occurs:

a. there is a better than 30% chance of rain within 24 hours; b. if during rain events, rain splash or surface rilling results in transport of sediment from

the pile to adjacent areas; c. work is stopped for more than 24 hours; d. if there are predicted sustained winds greater than 7 mph or wind gusts are causing dust

to rise and transport more than 25 feet from the edge of the pile. Watering can/will be used for dust abatement in lieu of placing the tarp during work hours.

7. Temporary silt fencing, straw mats, logs and filter fabric will be placed at the base of the work area to prevent migration of spoils outside the construction footprint. These materials will be left in place through the first spring following project completion. If feasible, log berm structures will be left in place after completion of the project.

8. Replaced roadfill and backfill material at both crossings will be compacted to a minimum of 95% in 6” lifts with adequate soil moisture to assure compaction compliance.

9. Spoils material not planned for re-use will be transported to a pre-approved disposal site and stored in a manner that prevents any sediment delivery to surface water. Potential storage areas include Trinity River Restoration Program sites, the Junction City DOT yard or other pre-approved locations. Excess spoils material that is endhauled to DOT yard(s) will be sorted and reprocessed into usable materials as appropriate.

Asphalt Recycling

Asphalt will be recycled and used as road surfacing material for unpaved roads if appropriate. Groundwater

Any groundwater encountered during excavation or installation of new footings will be pumped away from the stream and discharged in a vegetated flat area or depression. The vegetation will provide natural filtration of any sediment in the discharge water before it reaches the stream. Vegetation removal (clearing & grubbing)

Riparian vegetation, shrubs and conifer/hardwood trees along stream channels at each crossing and on the fill slopes at Crossing #2 may/will need to be removed, trimmed and/or topped to allow for detour bridge installation, fill removal, culvert excavation and placement, and/or to provide safe visual sighting distances. There is no acreage estimate for the amount of expected vegetation removal as only isolated trees will need to be removed. Approximately 75 trees are identified for removal from the road prism at Crossing #2. All efforts will be made to reduce the removal of vegetation and trees. Directional felling will be utilized to reduce impacts to the stream bank and retained vegetation. Temporary detour installation

At Crossing #1, the detour bridge will be placed immediately downstream of the concrete box culvert and will conform to the road shoulders. Minor rock placement at the road shoulders to transition the approaches to/from the bridge will be required. There are no underground or overhead utilities that will need to be relocated. At Crossing #2, a Bailey bridge will be installed over the crossing after the road surface and a portion of the fill are excavated to allow for placement. Excavation of the remaining fill


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and culvert will be completed from the upstream access road (working under the Bailey bridge). The detour, stream diversion structure(s) and fish screens will be removed prior to October 15. Erosion control and revegetation

All excavation and placement of roadfill/structural backfill and engineered streambed material will be done when the active stream is contained within the clean water bypass and with all applicable resource protection measures and BMPs (silt fencing, straw waddles and oil-absorbing booms) in place. The roadfill at Crossing #2 and all other disturbed areas (staging areas, stream banks, access road upstream of Crossing #2) will be revegetated with native grass, forb and tree species and mulched with certified weed free straw, wood mulch or similar suitable native material.

1. Jute rolls shall be securely staked, with full ground contact, around the base of any spoils piles or stockpiles that are present at the end of each workday or if operations are suspended for the day, and/or if there is greater than a 30% chance of measurable precipitation.

2. The staging areas and temporary fill storage sites will be reseeded with native grasses and mulched with woodchips from trees removed during the road excavation, pine needle mulch, and/or certified weed free straw. Mulch will be placed over a minimum of 90% of the disturbed area with a depth sufficient to break up rainwater impact but allow for seeding to respond and sprout though mulch cover.

3. Erosion control mulching consisting of native woodchips from trees removed during the road excavation, pine needle mulch, and/or certified weed free straw will be placed over a minimum of 90% of the disturbed area with a depth sufficient to break up rainwater impact but allow for seeding to respond and sprout though mulch cover.

4. Replanting with native grass, shrub and tree species will be done the first fall/winter following completion of the project.

Monitoring Requirements

5 Counties Monitoring Project monitoring will be performed by 5C staff to assess construction and BMP implementation effectiveness as follows:

• Photo point monitoring of before, during construction, and post construction activities. • Thalweg profile survey before and after the first winter following construction. This monitoring

may extend to additional years depending on 5C monitoring funding levels. • 1st year erosion control effectiveness monitoring consisting of site inspections to track mulch

cover movement, sediment deposition at silt fence lines and evidence of rill or slump development.

• Revegetation cover and tree/shrub survival rates in the 1st and 2nd year following completion.

Forest Service Monitoring The Forest Service may conduct monitoring of the project as part of the Regional BMPEP monitoring program, either as part of the randomly assigned pool or as site-specific selected site monitoring. BMPEP monitoring includes both implementation and effectiveness monitoring. Site-specific monitoring typically occurs if erosion problems are perceived or BMP violations are observed. In the instance of the Conner Creek Fish Passage Improvement Project, it is likely that monitoring will occur, since the BMPEP protocol for evaluating in-channel construction states that:

“All in-channel construction occurring in flowing or dry streams must be evaluated; up to the point where 5 evaluations have been completed. Evaluations beyond 5 are optional.”

The following evaluation protocols may be applied to the project:


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• E09 – Stream Crossings • E12 – Servicing and Refueling • E13 – In-Channel Construction Practices • E15 – Rip Rap Composition • V29 – Revegetation of Surface Disturbed Areas

In addition, administrative or in-channel evaluation protocols may apply to the project if it is selected for that type of monitoring.

VI. References Boberg and Kenyon 1979. California Department of Fish and Game Stream Inventory, Trinity County. CA Department of Fish and Game. Unpublished Coe, Drew B. R. 2006, Sediment production and delivery from forest roads in the Sierra Nevada, California, M.S. thesis, Colorado State University, Fort Collins, CO, 110 pp. California Department of Fish and Game. 2004. Recovery Strategy for California Coho Salmon. Dunham, Jason B.; Rosenberger, Amanda E.; Luce, Charlie H.; Rieman, Bruce E. 2007. Influences of wildfire and channel reorganization on spatial and temporal variation in stream temperature and the distribution of fish and amphibians. Ecosystems: DOI:10.1007/s10021-007-9029-8.. Five Counties Salmonid Conservation Program. 2001. Direct Inventory of Roads and Treatment- Trinity County Roads. California State Water Resources Control Board, Proposition 204 Program Agreement #9-164-250-0. Water Quality and Stream Habitat Protection Manual for County Road Maintenance in Northwestern California Watersheds (Roads Manual). www.5counties.org Gresswell, R.E. 1999. Fire and Aquatic Ecosystems in Forested Biomes of North America. Transactions of the American Fisheries Society 128:193-221 Interagency SEIS Team, 1994. Standards and guidelines for management of habitat for late-successional and old-growth forest related species within the range of the northern spotted owl - attachment a to the record of decision for amendments to forest service and bureau of land management planning documents within the range of the northern spotted owl, Portland, OR. Haskins, Donald M. 1983. An overview of the use of cumulative watershed impact analysis, Shasta-Trinity National Forest. Shasta-Trinity National Forest, unpublished. Jordan, Christine J. 2011. Fisheries Biological Assessment and Evaluation. Conner Creek Fish Passage Improvement Project. Prepared on behalf of the Trinity County Department of Transportation. Neary, Daniel G., Kevin C. Ryan, and Leonard F. DeBano, eds. 2005. Wildland fire in ecosystems: effects of fire on soils and water. Gen. Tech. Rep. RMRS-GTR-42-vol. 4. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 250 pp. North Coast Regional Water Quality Control Board (NCRWQCB), 2007 Water Quality Control Plan for the North Coast Region, Basin Plan.

http://www.5counties.org/


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SHN, 2006. Fish Passage Design for Conner Creek at Red Hill Road and Conner Creek Road. Five Counties Salmonid Conservation Program under CA Coastal Conservancy Grants 05030 and 08090. Unpublished. Taber Geo-Technical. Foundation Report for Conner Creek Road. Five Counties Salmonid Conservation Program under CA Coastal Conservancy Grant 08090. Unpublished. Taylor, Ross, M. Love, T. Grey, and A. Knoche. 2002. Final Report: Trinity County Culvert Inventory and Fish Passage Evaluation. Five Counties Salmonid Conservation Program. USDA Forest Service, 1994. Final Environmental Impact Statement, Shasta-Trinity National Forests Land and Resource Management Plan. Pacific Southwest Region. USDA Forest Service, 1995. Shasta-Trinity National Forests Land and Resource Management Plan. Pacific Southwest Region. USDA Forest Service, 2000. Water Quality Management for National Forest System Lands in California – Best Management Practices. Pacific Southwest Region, Vallejo, CA. USDA Forest Service, 2002. Best Management Practices Evaluation Program (BMPEP) User’s Guide. Pacific Southwest Region. USDA Forest Service, 2008. Hydrology Resource Assessment, Iron Complex. Shasta-Trinity National Forest BAER Team – Brad Rust, Team Leader; Angela Coleman and Steve Bachmann, Hydrologists.

USDA Forest Service 2009a, Watershed Analysis, Burnt Ranch and Soldier Creek Planning Watersheds, Trinity River Management Unit, Shasta-Trinity National Forest, Trinity County, California, unpublished document, 71 pp. USDA Forest Service, 2009b. Shasta-Trinity CWE 2009 Cumulative Watershed Effects Analysis, Shasta-Trinity National Forest, November 2008. Analysis by Don Elder, ACT2 Enterprise Team. USEPA 2001, Trinity River Total Maximum Daily Load for Sediment, U.S. Environmental Protection Agency Region IX, 77 pp. Zeimer, R.R., 1981. Roots and the stability of steep slopes, in Symposium on Erosion and Sediment Transport in Pacific Rim Steeplands, p. 343-357.


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Appendix A Best Management Practices from the “Water Quality and Stream Habitat

Protection Manual for County Road Maintenance in Northwestern California Watersheds” (Roads Manual)

Select BMP sections from the Roads Manual are provided here for reference. 4.A. 2. During any in-water work, minimize sediment impacts and ensure that no fish stranding occurs [see: 4-F Temporary Stream Diversions and Appendix B-8 and B-9]. 4.B. 8. Minimize disturbance of riparian vegetation during culvert improvement and repair operations and replace lost plants if needed to provide critical shade cover.

4.C. 1. Size crossings to handle most probable 100-year flood flows and associated debris and bedload, given the watershed and specific conditions present in each county. Site-specific constraints may warrant a different standard.

4.C. 2. See the County Engineer for determining the correct culvert diameter and length for a given stream crossing to meet hydraulic capacity requirements for flood risk and channel stability.

4.C. 3. Refer to the latest NMFS and DFG fish passage guidelines and criteria to size replacement culverts for fish passage in anadromous fish-bearing streams. Consult with NMFS and DFG early in the design process [see Appendix C].

4.D. 1. Consider a single span bridge as the first option for culvert replacement in anadromous fish bearing streams. Bottomless arch culverts or partially buried “embedded” culverts are preferred over non-embedded culverts for fish passage purposes. Baffled culverts or fishways (> 0.5% slope) are the least preferred of the passage improvements.

4.D. 4. Ensure that all replacement culverts on anadromous fish-bearing streams meet the most recent version of the NMFS & CDFG fish passage criteria and guidelines. Variances can be allowed where meeting the guidelines can be shown to be unreasonable or impractical, based on biological and/or hydrologic rationale.

4.D. 5. Have the County Engineer evaluate the site to be sure that the proposed replacement structure will not increase the flood risk or cause sediment routing problems.

4.D. 6. Only install replacement culverts in a dewatered site, with a sediment and flow routing plan [see: 4-F Temporary Stream Diversions].

4.D. 7. Store excavated spoils and equipment in a location that will prevent sediment delivery to watercourses [see: Chapter 5 - Spoil Disposal].

4.D. 8. Maintain equipment to prevent leaks that may reach streams and clean before use near watercourses. Keep all fuel storage and staging materials out of the riparian area.

4.D. 9. Place spill contingency resources to contain a small to moderate spill (1-10 gallons) at each job site where equipment is used. Install oil absorbent materials downstream of in-water work sites to trap accidental spills or leaks into streams from equipment. Keep a Notification Checklist for hazardous spills on site and use if spill into stream occurs [see: 8-C Accident Clean-up].

4.D. 10. Fully restore disturbed sites within the riparian area with a mix of native, riparian plant species where disturbance of the shade canopy was significant due to the replacement project. If bare dirt sites result, apply erosion control measures [see: Appendix B-4].


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4.D. 11. To design for the possibility of conduit failure due to blockage or other problem, include additional surface routes which will redirect flood waters into the natural drainage course at non-erosive velocities as soon as possible.

4.D. 12. Align culverts and other structures with the stream, with no abrupt changes in flow direction upstream or downstream of the crossing. This can often be accommodated by changes in road alignment or slight elongation of the culvert.

4.D. 13. Place bottomless arches and embedded culverts at or near the same gradient as the natural streambed and wider than the active stream channel. The active channel is considered to be the wetted channel up to the ordinary high water marks. Minimize the possibility that the new culvert will not cause any existing downstream channel enlargement to migrate upstream.

4.D. 14. At stream crossings, place embedded culverts at least one foot deeper than the streambed grade, or embedded at least 20% of its height; whichever is greater. If the culvert is placed too low, the inlet can easily plug and overflow. If the culvert is placed too high in the fill, flow could potentially undercut the inlet, and erode the streambed and fill at the outlet.

4.D. 15. Protect both the inlet and the outlet with armor to protect from scour, if feasible [see: Appendix B-3].

4.F. 1. Make sure the temporary diversion channel is capable of carrying the anticipated streamflows during the construction period. 4.F. 2. Where anadromous fish are present, work closely with a qualified agency or consulting fishery biologist who has the needed permits. For listed species, the incidental and direct take permits will require reasonable and prudent measures (RPMs) to be used. Follow these permit requirements under the supervision of the fishery biologist. 4.F. 3. Have the supervising biologist remove all fish out of the affected area before dewatering any stream section. If fish are still found stranded in the dewatered channel, immediately transport them to the active channel following the directions of the biologist (usually by netting, electrofishing and/or pumping the fish with an approved fish-friendly method). 4.F. 4. Complete the diversion before or after typical upstream fish migration periods (see Table 1-2 and ask local DFG fishery biologist for local timing). If this is not possible, install a diversion pipe capable of passing fish or other method approved by DFG [see: Appendix B-3.4 for baffle designs]. 4.F. 5. Maintain fish passage in the new channel at all times and make sure that the water pumping hose/culvert has an adequate screen to avoid fish entrainment, unless otherwise approved by NMFS and DFG [see: 3-B-3 Water Drafting for temporary screening practices]. 4.F. 6. Isolate the diversion channel from the natural channel during excavation. 4.F. 7. For each job site where equipment is used:

a) Install oil absorbent materials downstream of in-water work sites to trap accidental spills or leaks into streams from equipment. Store excavated spoils and equipment to prevent sediment delivery to watercourses [see: Chapter 5 – Spoil Disposal].

b) Ensure spill contingency resources to contain a small to moderate spill (1-10 gallons) are in place. 4.F. 8. Line diversion channel with filter fabric, visqueen or a similar material and anchor with rock or sandbags to hold it in place. The purpose is to prevent the bed and banks of the diversion channel from eroding at expected flows.


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4.F. 9. When diverting the flow into the temporary channel, first remove the downstream plug of the temporary channel, followed by the upstream plug. Next, close the upstream end of the natural channel and then close the downstream end. 4.F. 10. If a tributary enters the former channel within the diversion area, connect the tributary to the new dewatering channel. If any channel change is done to intercept a tributary, move the channel back to its original shape and location at the completion of the temporary diversion. 4.F. 11. To restore flow to the natural channel, first remove the downstream and then the upstream plug of the natural channel. Next, close the upstream end and the then the downstream end of the diversion channel. 4.F. 12. After removing any man-made material, backfill the diversion channel and stabilize the stream banks. Revegetate disturbed riparian areas with naturally occurring plants and grasses. 4.F. 13. An alternative to a temporary stream diversion channel is to impound the flow and transport the flow around the site via pumps and piping. This practice requires screening of the stream at the pumps and removal of any fish from the dewatered site after installing fish blocking screens above and below the site. 5.A. 1. Determine the location of existing disposal sites, potential disposal sites, and locations of significant spoil generation along county roads. Incorporate data collected from County Road Erosion Inventory as much as possible.

a) Conduct site investigations of existing and potentially suitable County disposal sites. Site investigations should include the disposal area size, distance to watercourses, potential slope instabilities, listed species habitat, archaeological sites, nearby residential areas, access, and other limiting factors.

b) Prepare a map and data set indicating sites (existing and potential) with acceptable site characteristics (see below). Prioritize acceptable sites and initiate the permitting process.

c) Develop site plans for sites adjacent to or near riparian areas or streams to identify erosion and sediment control needs, and to ensure stability of the material.

5.A. 2. Follow these acceptable site characteristics in the site election & design process: a) Seek a stable site where sediment cannot reach the stream during any high water event. b) Avoid adjacent riparian corridors or any area within the 100-year floodplain. c) Avoid all wetland sites as these sites are protected from disposal activities and permits will be

required and may not be granted. d) Avoid placing spoil on unstable slopes, where the added weight could trigger a land movement.

Excessive loading of clay or silt soils could also trigger a failure. e) Use wide, stable locations such as rock pits, ridges, and benches as places to dispose of fill.

Avoid locations where ground water emerges or a thick organic layer is present. f) Avoid sites with endangered or threatened plant species. Search the California Natural Diversity

Database [//www.dfg.ca.gov/whdab/html/cnddb.html] for any known listed plant sites in the area. Seek site evaluations by qualified botanists during the appropriate season before selecting a new site.

5.A.2. 1. Avoid placing excess spoils into stream courses and adjacent riparian zones where it could potentially result in sediment delivery to streams.


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5.A.2. 2. Drain spoil piles to prevent the concentration of flow and to prevent rill and gully erosion. 5.A.2. 3. Spread material not to be re-used in compacted layers and generally conforming to the local topography. 5.A.2. 4. Separate organic material (e.g., roots, stumps) from the dirt fill and store separately. Place this material in long-term, upland storage sites, as it cannot be used for fill. Leave all organic material that can safely remain in adjacent riparian zones. Make stored woody debris available to others as large wood for placement in streams for habitat improvement. 5.A.2. 5. Store “clean” material in a short-term disposal site (stockpile) if it will likely be re-used for fill or shoulder widening projects. Verify if material can be used for shoulder widening. [See: 5-B-1] 5.A.2. 6. Where feasible, recycle asphalt material in embankments and shoulder backing. Place these materials where they will not enter the stream system. Asphalt that is 5 years old is considered “inert” (that is, all oils washed off). 5.A.2. 7. Encourage stockpiling and reusing concrete materials when possible [see: 5-B-1].

5.A.3. 1. Do not add excess unusable material to permanently closed sites. a) Spread material not to be re-used in compacted layers, generally conforming to the local

topography. b) Design the final disposal site reclamation topography to minimize the discharge of concentrated

surface water and sediment off the site and into nearby watercourses. c) Cover the compacted surfaces with a 6-inch layer of organic or fine-grained soil, if feasible. d) After placement of the soil layer, track-walk the slopes perpendicular to the contour to stabilize

the soil until vegetation is established. Track walking creates indentations that trap seed and decrease erosion of the reclaimed surfaces.

e) Revegetate the disposal site with a mix of native plant species. Cover the seeded and planted areas with straw compost, mulched with straw at a rate of 1 to 1 ½ tons per acre. Apply jute netting or similar erosion control fabric on slopes greater than 2:1 if site is erosive.

5-B-1 Keep temporary disposal sites out of wetlands, adjacent riparian corridors, and ordinary high water areas as well as high risk zones, such as 100-year floodplain and unstable slopes. Anticipate sufficient storage area with no risk for sediment delivery for piles that may slump. Stress cracks indicate that the pile is at risk of slumping. See figure below. Follow BMPs in 6-D-4 (Outdoor Storage of Raw Materials), where possible. Reuse and recycle concrete, asphalt, and other construction waste when possible.


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Source: Choctawhatchee, Pea & Yellow Rivers Watershed Management Authority (2000) 1. 8-c-4 For spills on roadways:

a) Contain spill so it does not enter flowing waters of the stream system, including the storm drain system along the roads;

b) Ensure that each county road project site contains spill clean-up/ emergency response kits with sufficient materials to contain at least a small to moderate spill (1-50 gallons);

c) Minimize further tracking of spilled material.


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Appendix B Northwest Forest Plan Aquatic Conservation Strategy (ACS)

Northwest Forest Plan Aquatic Conservation Strategy (ACS): The project will implement Riparian Reserves, the Aquatic Conservation Strategy Objectives and Riparian Management (Prescription 9) objectives as follows:

• Maintain and restore the physical integrity of the aquatic system, including shorelines, banks and bottom configurations (page 4-53).

• Cooperate with Federal, state, and county agencies to achieve consistency in road design, operation, and maintenance necessary to attain Aquatic Conservation Strategy Objectives (page 4-54).

• New culverts, bridges and other stream crossings shall be constructed, and existing culverts, bridges and other stream crossings determined to pose a substantial risk to riparian conditions will be improved, to accommodate at least the 100-year flood, including associated bedload and debris. Priority for upgrading will be based on the potential impact and the ecological value of the riparian resources affected. Crossings will be constructed and maintained to prevent diversion of streamflow out of the channel and down the road in the event of crossing failure (page 4-55).

• Provide and maintain fish passage at all road crossings of existing and potential fish-bearing streams (page 4-55).

• Design and implement watershed restoration projects in a manner that promotes long-term ecological integrity of ecosystems, conserves the genetic integrity of native species and attains Aquatic Conservation Strategy objectives (page 4-58).

• Cooperate with other federal, state, local, and tribal agencies, and private landowners to develop watershed-based Coordinated Resource Management Plans or other cooperative agreements to meet Aquatic Conservation Strategy Objectives (page 4-58).

Design and implement fish and wildlife habitat restoration and enhancement activities in a manner that contributes to attainment of Aquatic Conservation Strategy objectives (page 4-58).

hydrology report conner creek fish passage improvement...

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