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2.1.5 Cofferdam Removal
2.1.5.1 Project Description
Following construction of the Combined Pumping Plant and Fish Screen, the cofferdam will be removed. Portions of the cofferdam that have been incorporated into the foundation of the facility will be cut at the sill elevation. Other portions will be cut at mud elevation in the river.
2.1.5.2 Construction Process and Mechanisms for Effect
Pilings will be cut underwater by divers with torches and removed using the boom equipment at the new facility. Mechanisms for effects to fish and wildlife would be temporary disturbance to the river bottom, sediment resuspension and turbidity as a result of disturbance, and temporary disturbance due to the presence of divers and cutting equipment.
2.1.6 Dismantling and Removal of Existing Diversion Structures
2.1.6.1 Project Description
Following construction, testing, and initial operation of the Combined Pumping Plant and Fish Screen, RD 108 will dismantle and remove existing diversion facilities. The existing water diversion facilities will be removed from Boyers Bend, Howells Landing, and Tyndall Mound pumping plants (Figures 12 through 14). This will involve removal of all equipment from the existing support structures that extend into the Sacramento River.
2.1.6.2 Construction Process and Mechanisms for Effect
Existing facilities can be decommissioned following the Swainson's hawk nesting season, during periods of low flow in the late summer and early fall (late August through early November). This will take approximately 7-14 days per facility. Above-water facilities will be dismantled and removed from the site by trucks for disposal. This equipment will be removed via the existing road and either re-used or hauled to an appropriate recycling center or landfill for disposal. This work can be performed in the dry and with divers in the river. Pilings and other below-water facilities will be cut at or below mud line by divers using cutting torches. Pilings will be lifted from the water by a crane. They will then be disposed of as above. Mechanisms for effects to fish and wildlife would be temporary disturbance to the river bottom, sediment resuspension and turbidity as a result of disturbance, and temporary disturbance due to the presence of divers and cutting equipment. Large trees and shrubs will remain in place, but removal of several pipes and associated equipment will expose bare earth (below the pipes) that will be subject to erosion following decommissioning.
Following decommissioning, it may therefore be necessary to provide for bank stabilization, but the methods used will depend on site conditions. Methods may include selective placement of riprap or other bank protection such as fiber mats and/or revegetation of levee slopes.

Figure 12. Aerial photograph of the Boyers Bend Pumping Plant site.

Figure 13. Aerial photograph of the Howells Landing Pumping Plant site.

Figure 14. Aerial photograph of the Tyndall Mound Pumping Plant site.

2.1.7 On-going Operation and Maintenance of Facilities
2.1.7.1 Project Description
Water diversions at the Proposed Project will occur on a variable schedule, depending on weather conditions and cropping patterns. In general, the irrigation schedule begins in the late winter or early spring and ends by mid fall.
Operation of the new Proposed Project elements will require:

On-going maintenance and repair of the combined pump/fish screen facility. This work will be conducted within the 4.4-acre facility site, which will include a gravel pad to the west of the screen where heavy equipment (cranes, etc) may be placed for repair work. There is some potential that repair and maintenance of the screen cleaner may require work in the wet (divers). Each screen panel would be removable to allow for annual pressure washing, cleaning and maintenance, as well as inspection of screen integrity.

Operation and Monitoring of the continuous fish screen cleaner. Debris-related turbulence along the face of a fish screen may create eddies and affect the uniformity of flow across the face of the screen and thus create non-uniform approach velocities. The fish screen cleaner would therefore be operated and maintained to reduce debris and sediment accumulation that would adversely affect the magnitude and uniformity of approach velocities by creating turbulence in front of the screen. Sediment deposition adjacent to the screen structure has the potential to obstruct a portion of the cross-sectional area of the fish screen resulting in increased approach velocities. Sediment deposition may also affect localized hydraulic current patterns and associated sweeping velocities across the screen surface. Furthermore, sediment accumulation may adversely affect the ability to remove debris and maintain the full functional screen area required to provide uniformity of approach velocities within the design criteria established by CDFG and NOAA Fisheries. Control and maintenance of sediment deposition have been identified as important factors affecting the operational performance of positive barrier fish screens located on the Sacramento River. The fish screen would be equipped with a screen cleaning brush that would be operational throughout the period of diversion operations. In addition to the screen cleaning brush, individual screen panels would be removed periodically for inspection and removal of debris as part of routine maintenance. This technology is well tested and debris build up on the fish screen is unlikely; this maintenance therefore ensures appropriately uniform approach velocities across the screen.

Maintenance dredging. Analysis of site hydraulics suggests that sediment accumulations are not likely at this location, and sediment accumulations are likely to be removed naturally under most conditions. Maintenance dredging to remove sediment accumulations may be required, but it will be on an infrequent basis. Dredge spoil would be placed on the west side of the afterbay (where sediment accumulations in the afterbay will also be disposed of). Consistent with current practices for the disposal of excess sediment from project operations at the Wilson Bend Fish Screen, spoil from dredging will be sold.

Intake maintenance would be facilitated by a boom truck or mobile crane, which can be used to remove individual screen panels for cleaning, maintenance, and repair as needed. A portable, high-pressure wash water system would be provided to facilitate screen panel cleaning. It is anticipated that prior to each irrigation season screen panels would be removed for inspection, repair, and high-pressure washing. Backup panels would be available on-site to replace screen panels that require maintenance or repair. A sediment jetting system would also be included in the fish screen bay design to reduce sediment deposition and accumulation within the fish screen. The sediment jetting system has been successfully tested in a similar fish screen structure at the RD 108 Wilkins Slough facility. Operation of the sediment jetting system would not affect sediment deposition, water quality, or potential maintenance within the Sacramento River on the outside of the intake structure.

Routine dredging and disposal of sediment in the afterbay. Again, all work would be within the 4.4-acre site. Dredge spoil may be stockpiled on site until adequate amounts of this fill material can be collected by commercial operators for use in other construction projects.

On-going canal repair and maintenance. Inspection and mechanical maintenance can be accomplished within the 40-to-60-foot permanent right-of way of the canal. If there is a need for major construction activity, then a temporary construction right-of-way on adjacent agricultural lands may be obtained. Concrete lining of canals provides for substantially lower frequency of maintenance, and routine dredging is not generally required.

2.1.7.2 Construction Process and Mechanisms for Effect
On-going operations and maintenance activities will result in routine traffic along the roads leading to the facilities for staff to access and operate the facilities and for inspection and maintenance. Facilities, such as concrete-lined canals, have been designed to minimize maintenance needs. Routine maintenance will create short-term noise, dust, and visual disturbance to wildlife. Dredging may result in resuspension of sediments.
The Combined Pumping Plant and Fish Screen may be overtopped in floods greater than those occurring on a 100-year interval. The facility is designed to withstand such events, although repair may be needed. If such events occur, the facility is designed to drain freely and no fish rescue will be required.

2.1.8 Construction Schedule
Construction will occur over a period of approximately 24 months (see Table 3-1, above). For the Combined Pumping Plant and Fish Screen, the timing of cofferdam construction will determine start and end date of the construction period. The cofferdam must be constructed outside of the flood period, which is generally from November 1 through March 31 (although the official end of the flood period may vary by year). The preferred schedule for cofferdam construction would be from July through November, when low flow conditions are anticipated and downstream juvenile salmonid migrations have been completed. Alternatively cofferdam construction could begin at any time following April 15.
Once cofferdams have been installed, all work on the Combined Pumping Plant and Fish Screen will occur in the dry and no effects on aquatic resources will occur during this period unless floods overtop the cofferdam and a fish rescue effort is required to remove stranded fish from behind the cofferdam during dewatering of the site. It is not possible to determine the frequency of dam overtopping, as hydrologic conditions on the Sacramento River are highly variable by year type. The probability of cofferdam overtopping is low during the 2-year construction period. If the cofferdam is overtopped, it is most likely to occur in winter
2.1.9 Other Measures added to the Proposed Project to Avoid and Minimize Project Impacts
Consistent with NEPA and CEQA guidance, conservation measures may be incorporated into the project description rather than being addressed as mitigation measures. Such incorporation (a) ensures implementation as a feature of the approved project and (b) focuses mitigation discussions on only those aspects of the project where project effects must be offset by a mitigative action. Conservation measures are included to address anticipated environmental effects. There is no nearshore riparian vegetation at the site of the Combined Pumping Plant and Fish Screen. Under low flow conditions, the shoreline is riprapped and there is a bare bank. The site was selected because of local erosive flow conditions which routinely scour the benthic environment at the site. There is dominantly non-native scrub vegetation on the bench facing the river and ruderal vegetation on the levee upslope.
Based on results of biological surveys conducted at the proposed sites for the Proposed Project and an evaluation of the potential adverse effects that may directly or indirectly affect protected species or their habitat, a series of conservation measures were identified and have been incorporated as part of the proposed project description. Conservation measures have been included for Swainson’s hawks, giant garter snakes, valley elderberry longhorn beetle, steelhead, winter-run and spring-run Chinook salmon, critical habitat for winter-run Chinook salmon, proposed critical habitat for spring-run Chinook salmon and Central Valley steelhead, and EFH for Pacific salmon. Conservation measures are briefly discussed below and summarized on Table 2-2.
Table 2-2. Summary of Conservation Measures incorporated into the Project Description.

Purpose	Conservation measure
Purpose	Monitoring	Management Action
Fish Conservation Measures
Turbidity Control to reduce effects on aquatic species	Twice daily turbidity monitoring during periods when construction may create turbid conditions	Modify activities as appropriate.
Control of petroleum product discharges	On-going construction monitoring to ensure compliance with RWQCB regulations	Comply with RWQCB permit conditions, including provisions for control of petroleum discharges and erosion control during construction Siting of staging and maintenance areas outside of drainage to watercourses Replanting of erodable areas immediately following completion of construction
Hazardous materials control	On-going construction monitoring to ensure compliance with RWQCB regulations	Develop and comply with a hazardous materials management plan to be approved by the RWQCB
Fish rescue	Monitor water depth and condition during dewatering of the area behind cofferdams following initial construction and if overtopped during construction.	Fish rescue and relocation to mainstem river as dewatering proceeds.
Fish protection during screen operation	Start up and on-going monitoring of screen condition and performance per AFSP and NOAA Fisheries guidelines; monitoring of debris	Routine screen maintenance prior to each diversion season; immediate maintenance if screen performance is affected by damage or debris
Swainson's Hawk Protection Measures
Avoid and minimize effects of construction activity on nesting hawks	April-May survey of nest locations within 0.5 miles of Action Area; monitoring per CDFG requirements if nest disturbance avoidance measures are required during construction.	Consultation with CDFG to determine effects and develop minimization plan, including possible changes in timing of construction activities Compliance with impact minimization plan
Giant Garter Snake and Northwestern Pond Turtle Conservation Measures
Avoid and minimize adverse impacts of construction on giant garter snake and northwestern pond turtle	Pre-construction surveys of Action Area 24-hours in advance of construction; pre-construction surveys will be repeated after any break in construction of 14 days or more. Biologist will be on call during construction with the authority to halt construction. Compliance monitoring when snakes identified in construction area.	Construction within 200 feet of suitable aquatic habitat will not occur except at the borrow pit south southeast of Tyndall Mound. To extent feasible, borrow will be removed during May 1-Oct 1. (Construction in winter will not affect suitable habitat because there is no estivation habitat at the borrow pit site.) Dewatering of GGS habitat 15 days prior to construction in GGS habitat areas (no GGS habitat will be dewatered as a result of the project). Clearing of wetland habitat to be minimized Environmental awareness training will be provided to all construction staff. Snakes found in construction areas/roadways shall be allowed to escape – capture/relocation of trapped/injured snakes not allowed. No monofilament or plastic in erosion control matting -- matting will be comprised of jute, straw, coconut matting, or other natural fibers. Construction speed limits shall be 15 mph when working within 0.5 miles of the potential GGS habitat at the Main Drain, except on existing paved roads. Movement of heavy equipment to and from the Main Drain borrow site shall be restricted to established paved and unpaved roadways to minimize habitat disturbance.
Valley Elderberry Longhorn Beetle Conservation Measures
Dust control	Monitor dust.	Develop and implement a Dust Control Plan.

2.1.9.1 Central Valley Steelhead, Winter-Run and Spring-Run Chinook Salmon, Winter-Run Chinook Salmon Critical Habitat, Proposed Critical Habitat for Spring-run Chinook Salmon and Central Valley Steelhead, and EFH for Pacific Salmon; Non-salmonid Mainstem Fish Species (green sturgeon, river lamprey, Pacific lamprey, hardhead, California roach, and Sacramento splittail).
Because the mechanism for effects to salmonid species and their habitat in the vicinity of the project is the same for all salmonids, conservation measures incorporated into the project for their protection are correspondingly the same. These conservation measures are also applicable to the suite of non-salmonid mainstem river species (Table 2-2). It should be noted that the non-salmonid fish in the Sacramento River, including those specifically addressed in the EA/Initial Study, are generally better adapted to high turbidity and wide ranges of flow and temperature than salmonids. Measures that are protective of riverine conditions for salmonids will generally provide even greater effective protection for the non-salmonid species; for example, salmonids are more sensitive to turbidity than are hardhead or California roach. The conservation measures incorporated into the project were developed in consultation with USBR, USFWS, NOAA Fisheries, and CDFG staff during the planning process for the Proposed Project.
Measure 1: Turbidity Control during Construction
To reduce turbidity in the mainstem channel of the Sacramento River during placement of the cofferdam, RD108 would monitor periods of construction activity and would coordinate with the contractor to identify periods when increases in mainstem river turbidity may occur. If a visible plume of turbidity greater than 300 feet (91 meters) in length is noted during cofferdam construction, RD108 would monitor turbidity levels within the plume. To the extent possible, construction methods would then be modified to maintain turbidity within the water quality criteria established by the Regional Water Quality Control Board (RWQCB) for the Sacramento River. The Proposed Project would be required to comply with water quality criteria established by applicable State and Federal permits and approvals for the Proposed Project. This conservation measure is in compliance with the Fisheries Management Plan for Essential Fish Habitat for Pacific Salmon, which recommends the following conservation measures for dredging and spoil disposal (Pacific Salmon FMP, Appendix A, A-88):

Explore collaborative approaches between material management partners, pollution control agencies, and others involved in watershed planning to promote use of best management measures to control sediment input;

Monitor dredging activities especially contaminate[d] sediments and regularly report effects on EFH. Re-evaluate activities based on results of monitoring;
Employ best engineering and management practices for all dredging projects to minimize water-column discharges. Avoid dredging during juvenile outmigration through estuaries; and
Consider upland disposal options as an alternative [to open water disposal].

Measure 2: Fish Rescue Program
Installation of the cofferdam and dewatering of the area behind it during Combined Pumping Plant/Fish Screen Construction may result in stranding and the loss of protected fish and other species. This stranding may or not be significant (fish rescue from the pool behind the cofferdam at the RD108 Wilkins Slough facility resulted in rescue of a single fish). RD108 would ensure that a qualified fishery biologist would design and conduct a fish rescue and relocation effort to collect fish from the area behind the cofferdam ("qualified biologists" for all aspects of the project will have suitable USFWS, CDFG, and NOAA Fisheries permits and permissions for required activities). The fish rescue effort would be implemented during the dewatering of the area behind the cofferdam and would involve capture and return of those fish to suitable habitat within the Sacramento River. To ensure compliance, a fisheries biologist shall be present during construction and pumping (dewatering) activities. The fish rescue plan (Appendix B) would be provided for review and comment by NOAA Fisheries, USFWS, and CCDFG prior to implementation.
As part of implementation of this measure, RD108 would monitor progress of installation of the cofferdam and the schedule for dewatering and would coordinate the dewatering schedule with the construction contractor and fishery biologist to allow for the rescue to occur when water depths are approximately 2 feet (0.6 meters). Information on the species and sizes of fish collected in the rescue and estimates of survival immediately before release would be recorded and provided to USFWS, CDFG, and NOAA Fisheries.
The success of this dewatering measure would be the effective capture and removal of fish from the forebay area to be dewatered with a minimum of capture and handling mortality for those fish returned to the Sacramento River.
During the two years of construction, fish rescue will be conducted on an as-needed basis, depending on whether flows in the river overtop the cofferdam. The cofferdam will be substantially higher than anticipated normal-year flows, and this fish rescue will not be needed except during flood events. See Sections 5.0 and 6.0.
Measure 3: Water Quality Management
Conservation and avoidance measures would be implemented in accordance with the RWQCB’s requirements dated June 6, 2003. Each of these conservation measures is briefly discussed below.

The discharge of petroleum products or other excavated materials to surface waters is prohibited;
Activities shall not cause turbidity increases in surface waters to exceed:

(a) Where natural turbidity is between 0 and 5 Nephelometric Turbidity Units (NTUs), increases shall not exceed 1 NTU;

(b) Where natural turbidity is between 5 and 50 NTUs, increases shall not exceed 20 percent;

(d) Where natural turbidity is greater than 100 NTUs, increases shall not exceed 10 percent.

Except that these limits would be eased during in-water working periods to allow a turbidity increase of 15 NTU over background turbidity as measured in surface waters 300 feet (91 meters) downstream from the working area. In determining compliance with the above limits, appropriate averaging periods may be applied provided that beneficial uses would be fully protected.

Activities shall not cause settleable matter to exceed 0.1 ml/l in surface waters as measured in surface waters 300 feet (91 meters) downstream from the project;
Activities shall not cause visible oil, grease, or foam in the work area or downstream;
All areas disturbed by project activities shall be protected from washout or erosion;
In the event that project activities result in creation of a visible plume in surface waters, the project manager will initiate monitoring of turbidity levels at the discharge site and 300 feet (91 meters) downstream, taking grab samples for analysis of NTU levels twice per day during the work period while the visible plume persists.

RD108 shall notify the RWQCB, CDFG, and NOAA Fisheries immediately if the above criteria for turbidity, oil/grease, or foam are exceeded; and
RD108 shall notify the RWQCB, CDFG, and NOAA Fisheries immediately of any spill of petroleum products or other organic or earthen materials.

Water quality surveys would be conducted during dredging operations and installation/removal of the cofferdam to ensure that turbidity levels do not increase in surface waters as described above. The project field manager will be responsible for monitoring in accordance with established protocols and survey procedures. In the event that turbidity levels do increase over the above stated NTU levels, the Company shall notify the RWQCB, CDFG, and NOAA Fisheries immediately.

Measure 4: Long-term Monitoring and Maintenance of the Screen
To ensure that the fish screen operates as intended and incidental mortality associated with diversions at this facility are in conformance with the goals and objectives of the project, long-term monitoring of operation and maintenance of the positive barrier screen would be conducted. Monitoring would include approach velocity measurements immediately after initiation of the positive barrier screen operations, with fine-tuning of velocity control baffles as necessary, to achieve uniformity of velocities in conformance with the CDFG and NOAA Fisheries criteria (0.33 ft/sec). Consistent with the operational protocols for other similar facilities, RD108 would also monitor the condition of the screen on an annual basis, and would do periodic visual inspections to remove accumulated debris and repair screen panels as necessary. CDFG and NOAA Fisheries would have access to the positive barrier screen for underwater inspections following completion of intake screen construction. The standards for success would be long-term reliable operation of the fish screen, and conformance with intake screen design criteria. When screen baffles have been calibrated at the beginning of the irrigation season, the screen is expected to perform as designed and to meet NOAA-Fisheries and CDFG approach velocity criteria under normal flow conditions . Screen function will be monitored on an on-going basis using a drift head gauge to measure the difference in pressure on the outside and inside of the screen. A consistent difference in pressure is an indication of proper screen functioning and cleaning; an increase in the differential pressure is an indicator of screen clogging by debris. Using this approach, it will be possible to monitor screen performance on a real-time basis and to rapidly identify conditions which indicate potential problems with screen function.
As long as equipment is not damaged and the screens are maintained, the facility should meet these operational criteria indefinitely. As noted in the Project Description, RD 108 will conduct routine inspections and tests of the brush system, will routinely inspect screens to ensure that they have not been damaged and meet specifications, and will monitor sediment accumulations on an on-going basis to ensure that sediment accumulations do not affect screen performance. Visual inspections will occur daily; the frequency of equipment inspection monitoring will be based on river conditions and observed debris loads. Monitoring will be more frequent during periods when debris loads are high. If equipment is found to be dysfunctional, it will be replaced or repaired.
The Proposed Project fish screens and the brushing system would be mounted so that they may be replaced rapidly if they are damaged. In this event, diversions would be halted until a replacement screen can be installed. A replacement screen will be kept on site to minimize the time during which fish would be exposed to a defective (but not operating) screen.
Measure 5: Hazardous Materials Control and Spill Prevention and Response Plan
The construction contractor would be required to prepare and implement a hazardous materials control and spill prevention and response plan. Measures would include, but would not be limited to, the following:

Prevent raw cement, concrete or concrete washings, asphalt, paint, or other coating material, oil or other petroleum products, or any other substances that could be hazardous to aquatic life from contaminating the soil or entering watercourses, including ditches and canals;
Establish a spill prevention and countermeasure plan before project construction that includes strict on-site handling rules to keep construction and maintenance materials out of drainage and waterways;
Clean up all spills immediately according to the spill prevention and countermeasure plan, and notify CDFG and the Central Valley RWQCB immediately of spills and cleanup procedures; and
Provide staging and storage areas for equipment, materials, fuels, lubricants, solvents, and other possible contaminants away from watercourses and their watersheds.

The plan would be prepared by the construction contractor for the Proposed Project and should be implemented before the construction phase begins. USFWS, CDFG, NOAA Fisheries, and RWQCB staff would review the plan to verify that hazardous material control and spill response measures have been incorporated to control the use of hazardous materials and reduce the chance of spills to the maximum extent practicable. USFWS, CDFG, NOAA Fisheries, and the RD108 engineer would inspect construction activities to ensure compliance with this measure.

Measure 6: Erosion Control Plan and Stormwater Pollution Prevention Plan
A soil erosion control plan would be prepared by the contractor prior to grading and excavation activities to minimize potential effects of silt entering the river and increasing river turbidity. The project specifications require that the construction contractor prepare an erosion control plan and a stormwater pollution prevention plan. The plan would include, but would not be limited to, the following measures to minimize erosion and sedimentation:

Use sedimentation basins and straw bales or other measures to trap sediment and prevent sediment and silt loads to the Sacramento River during construction;
Cover graded areas adjacent to the levee with protective material, such as mulch, and re-seeded with adapted native plant species after construction is complete;
Incorporate retaining walls into the project design on both the north and south sides of the intake forebay to minimize erosion of soils into the Sacramento River;
Minimize surface disturbance of soil and vegetation;
Place any stockpiled soil where it would not be subject to accelerated erosion; and
Commence re-vegetation and placement of erosion control devices, such as crushed rock, as soon as a graded area (or other area disturbed such as river bank areas at decommissioned facilities) has attained finish grade.

The construction contractor for the Proposed Project, using the services of a certified erosion control specialist or California-registered civil engineer, would prepare the plan. The plan would be prepared and implemented before the construction phase begins. CDFG, RWQCB staff, and the RD108 engineer would review the plan to verify that physical best management practices (BMPs) have been incorporated to reduce erosion and sedimentation to the maximum extent possible and ensure compliance with this measure. Erosion and sedimentation would be reduced to the maximum extent possible according to the BMPs being used.

2.1.9.2 Swainson’s Hawk
If construction were scheduled during the Swainson's hawk nesting season (approximately mid-April through August), RD108 would ensure that a qualified biologist would survey, during April to mid-May, the area within 0.5 miles from the project construction area for adult hawks and potential or active nest sites prior to the onset of construction. If a breeding pair of Swainson's hawks was found within this area, the biologist would coordinate with CDFG regarding appropriate construction activities regarding construction activities that may be permitted, including consideration of modifying activities or potentially ceasing activities during the nesting period. Monitoring would be performed in accordance with guidelines in “Staff Report Regarding Impacts to Swainson’s hawk (Buteo swainsoni) in the Central Valley of California” (CDFG 1994).
In the event that active Swainson’s hawk nests are found within 0.5 miles of the Proposed Project, the biologist would consult with CDFG to determine if the potential for nest abandonment exists. If it is determined by CDFG that an adequate buffer is present between the nest and the Proposed Project, then no mitigation would be required. If the biologist and CDFG determine that the potential for nest abandonment exists, short-term modifications, including halting construction activities, may be required by CDFG until young have fledged and are no longer in the nest. In addition, canal construction during nesting season may be scheduled for areas outside of potential disturbance zones, with areas where disturbance may occur scheduled for post-nesting construction.
2.1.9.3 Giant Garter Snake and Northwestern Pond Turtle
RD108 would be responsible for insuring that the giant garter snake and northwestern pond turtle mitigation is conducted under the supervision of a qualified biologist. Standard measures, as approved by the USFWS and CDFG, to minimize the risk of death, injury, or displacement of any giant garter snakes that may be present in the Action Area will be observed prior to removal of borrow material, placement of material in the stockpile locations, and canal construction, and. Conservation measures to reduce potential effects to giant garter snakes and northwestern pond turtles will include, but not be limited to, the following:

All work within potential giant garter snake habitat, including activities within suitable aquatic habitat and activities within 200 feet (about 60 meters) of supporting upland habitat, will occur between May 1 and October 1, which coincides with the active season of this snake. There is no suitable estivation habitat at the borrow site south southwest of Tyndall Mound, which is planted in many years and maintained free of weeds and utilized as an access road during periods when it is not planted. Suitable mammalian burrows for giant garter snake estivation are not evident at the site. Therefore, removal of borrow from this site may continue outside of May 1 to October 1.

Prior to initiation of construction activities, a qualified biologist will survey the Action Area adjacent to any suitable habitat to confirm that there are no giant garter snakes or northwestern pond turtles present. If snakes/turtles are present they would be allowed to move away from construction activities on their own. Pre-construction surveys would be reinitiated if construction adjacent to suitable habitat is suspended for a period of 14 days or more and then re-started.

Although no suitable GGS aquatic habitat is intended to be dewatered by the project, in the event that it is needed, aquatic habitat will be dewatered at least 15 days prior to the initiation of construction activities. If complete dewatering is not possible, potential snake prey (e.g., fish and tadpoles) will be removed so that snakes and other wildlife are not attracted to the construction area;

Construction and maintenance personnel will participate in a USFWS-approved worker environmental awareness training program. Under the guidelines of this program, workers shall be informed about the presence of giant garter snakes and habitat associated with the species and that unlawful take of the animal or destruction of its habitat is a violation of the ESA. Prior to construction activities, a qualified biologist approved by the USFWS shall instruct construction personnel about: 1) the life history of the giant garter snake; 2) the importance of irrigation canals, marshes/wetlands, and seasonally flooded areas, such as rice fields, to the species; and 3) the terms and conditions of the biological opinion. Colored photographs of the giant garter snake would be distributed during the training session for posting on the job site. Proof of this instruction shall be submitted to the USFWS. The northwestern pond turtle also can be addressed during this program:

At no more than 24 hours before the start of construction activities in or adjacent to giant garter snake habitat, the project site will be surveyed for giant garter snakes and northwestern pond turtles by a qualified biologist. Surveys of the project area will be repeated if a lapse in construction activity of two weeks or greater occurs;

The monitoring biologist will be available thereafter on an on-call basis. If a giant garter snake is encountered during construction activities, the biologist would have the authority to halt work in the area immediately adjacent to the snake until appropriate corrective measures have been implemented or it is determined that the snake would not be harmed;

Vegetation clearing will be confined to the minimal area necessary for Combined Pumping Plant/Fish Screen Construction and fill placement;

To the extent possible, construction activities within 200 feet (60 meters) from the banks of snake aquatic habitat will be avoided;

When working or driving within 0.5 miles of suitable aquatic habitat for giant garter snakes and/or northwestern pond turtles, project-related vehicles shall observe a 15-mph speed limit within construction areas, except on county roads, and State and Federal highways. This is particularly important during periods when the giant garter snake may be basking or moving on roadways;

Movement of heavy equipment to and from the project site within 0.5 miles of suitable aquatic habitat for the giant garter snake shall be restricted to established paved and unpaved roadways to minimize habitat disturbance;

Any erosion control matting will not include monofilament or plastic. Rather, the matting would be comprised of jute, straw, coconut matting, or other natural fibers; and

Giant garter snakes encountered during construction activities will be allowed to move away from construction activities on their own. Capture and relocation of trapped or injured animals will not be allowed.

Northwestern pond turtles encountered during construction activities may be collected and relocated to areas outside of the construction zones.

Monitoring will be performed by a qualified Service-approved biologist in accordance with established protocols and survey procedures. The monitoring biologist would be available on an on-call basis. In the event that a giant garter snake is found at the construction or stockpile site, work in the immediate area will be halted, USFWS and USBR would be notified, and work would not resume until appropriate corrective measures have been implemented or it is determined by a USFWS-approved biologist that the snake would not be harmed. The biologist will report any snakes encountered and any incidental take of the snakes to the Chief of the Endangered Species Division at the Sacramento Fish and Wildlife Service Office immediately, within three (3) working days

2.1.9.4 Valley Elderberry Longhorn Beetle
No elderberry shrubs are located within 100 feet (30 meters) of the construction rights-of-way. There is thus no mechanism for direct impacts to the valley longhorn elderberry beetle or its habitat. Construction and construction traffic may generate dust which could indirectly affect elderberries. To minimize the potential for such (minor) indirect effects, RD108 will apply for construction permits from Yolo County and Colusa County Air Quality Management Districts and will comply with all applicable rules for construction projects. Impact minimization measures will include:

Construction equipment will be fitted with best available emissions control technology, as specified by the manufacturer, and routine equipment inspection and maintenance will be undertaken to ensure that equipment is functioning properly.
RD108 will prepare a Dust Control Plan for approval by Yolo County and Colusa County Air Quality Management Districts. At a minimum, this plan will incorporate the following measures:

(1) Disturbed areas shall be stabilized for the duration of the construction

activity or until construction work resumes on the inactive disturbed area. All disturbed areas of a construction site, including storage piles of fill dirt and other bulk materials, which are not being actively utilized for construction purposes for a period of seven (7) calendar days or more, shall be stabilized using one or more of the following approved soil stabilization methods to effectively limit vehicular dust emissions (VDE) as defined by section 3.4 of this Rule. Where soil moisture or natural crusting is sufficient to limit visible dust emissions, no action is required.
(a) Where water is used as the dust suppressant, watering shall be applied to effectively limit VDE, or
(b) Where a chemical dust stabilizer or suppressant is utilized, the stabilizer or suppressant shall be applied to effectively limit VDE;
(2) All operations shall effectively limit VDE from on-site unpaved roads and off-site unpaved access roads using one or more of the following stabilization methods. Road stabilization shall be maintained for the duration of the activity. Where soil moisture is sufficient to meet this requirement, no action is required;
(a) Where water is used as the dust suppressant, watering shall be applied to effectively limit VDE;
(b) Where a chemical dust stabilizer or suppressant is used, the stabilizer or suppressant shall be applied to effectively limit VDE;
(3) All operations shall limit or remove the accumulation of mud or dirt from public paved roads, including shoulders, adjacent to the site at the end of the work day, or at a minimum of once every twenty-four hours when operations are occurring;
(4) In addition to restrictions imposed by local agencies, removal of deposited mud/dirt carryout from a paved road will not be accomplished with dry rotary brushes, except where preceded or accompanied by sufficient wetting to limit the VDE; and no blower devices will be used for removal of deposited mud/dirt carryout from subject paved roads;
(5) Where feasible, paved access aprons, gravel strips, wheel washers, or other measures designed to limit mud and dirt deposits on public paved roads will be employed;
(6) All areas used for storage of construction vehicles, equipment, and materials shall comply with the applicable provisions of Yolo County and Colusa County Air Quality Management Districts; and
(7) During transit, all loads shall have freeboard and shall be covered.
In general, RD108 intends to apply water as the primary dust control measure, and not to utilize chemical dust suppression materials. References to chemical dust suppression, above, are taken from Yolo County and Colusa County Air Quality Management Districts have been made only to reflect RD108's intention to comply with all dust suppression requirements.
2.1.9.5 Management of Cultural Resources Activities
To address the potential for buried cultural resources in construction sites, primarily associated with excavations associated with new canal and canal replacement, RD108 will prepare an Historic Properties Treatment Plan (HPTP) specifying measures to be taken if buried cultural resources are found. This HPTP, or other programmatic document approved by USBR, can be submitted to the State Historic Preservation Office (SHPO), and coordinated with the regional Native American community, for approval prior to initiation of construction.
The HPTP/other programmatic document shall include provisions for education of construction personnel in the identification of such materials and the appropriate response to any discovery of buried cultural resources. The HPTP shall provide for appropriate monitoring by qualified cultural resource monitors during construction in any area with potential for buried resources. Among the measures included in the HPTP shall be provisions for a pre-construction testing program in areas where there is a high potential for finding buried cultural resources. The HPTP shall comply fully with all State of California and Federal regulations regarding the treatment of historic properties. RD108 has realigned several segments of canal to avoid known cultural resource sites, and to the extent feasible will avoid impacts through such realignment. Where avoidance is not feasible, RD108 shall provide for appropriate resource recovery and documentation.
In the event that cultural resource recovery is necessary, RD108 will provide for protection of special-status wildlife species in the same manner as proposed above. Specifically, cultural resource excavation areas shall be inspected each day before work proceeds to determine if wildlife have become trapped in the excavation areas. Excavation areas will include earthen ramped sections to allow wildlife to escape from them. In the even that wildlife found in excavation areas need assistance, a qualified biologist will be contacted to assist in their removal. Cultural resources personnel will be included in all impact avoidance educational programs given to construction staff.
2.1.9.6 Enhancement Measures
Although giant garter snake use of RD 108 facilities appears to be at best incidental, RD 108 will consider installing a hibernaculum for giant garter snake use for winter estivation if a suitable site can be found that will allow for use by the giant garter snake in a manner which (a) would not attract snakes to a site where they would be exposed to adverse impacts from predation or poor summer habitat conditions and (b) would not create conflicts between RD 108 operations and snake use of the estivation habitat and/or adjacent habitats.

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