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Staff Report 3876
City of Palo Alto (ID # 3876) City Council Staff Report Report Type: Consent Calendar Meeting Date: 6/10/2013 City of Palo Alto Page 1 Summary Title: Bonde Weir Fish Passage Improvement Project Title: Adoption of a Park Improvement Ordinance for the San Francisquito Creek Bonde Weir Fish Passage Improvement and Channel Stabilization Project From: City Manager Lead Department: Community Services Recommendation Staff recommends that the Council approve a Park Improvement Ordinance (Attachment A) for the San Francisquito Creek Bonde Weir fish passage improvement and channel stabilization project. Discussion The Bonde Weir fish passage and channel stabilization project (or project) (Attachment B) is located in San Francisquito Creek, which separates the cities of Palo Alto and Menlo Park. The project site occupies a portion of the border between Menlo Park and Palo Alto about 1.7 miles southwest of U.S. Highway 101 near El Camino Real Bridge (Appendix A). The project proposes to remove a bank-to-bank concrete sill, known as the Bonde Weir, that acts as a barrier to fish passage under current conditions and replace it with a re-graded and "roughened" channel. This channel type uses engineered streambed materials to maintain and improve stability over a wide range of stream flows while providing vastly improved conditions for fish migration and movement. In particular, the project is intended to benefit steelhead trout (Oncorhynchus mykiss), as the San Francisquito Creek watershed provides habitat for this species. The watershed is part of the Central California Coast Steelhead Evolutionarily Significant Unit in which steelhead are considered "threatened" under the federal Endangered Species Act. The project also will improve channel stability over existing conditions. The Bonde Weir was recognized by the San Francisquito Creek Watershed Council – Steelhead Task Force as a barrier to steelhead (Oncorhynchus mykiss) passage. At times, in‐migrating adult as well as out‐migrating smolt steelhead trout may be delayed or prevented from passing City of Palo Alto Page 2 the weir. The San Mateo County RCD, the project sponsor, received a grant from the mitigation funds generated by the Bay Bridge Project and administered by the National Marine Fisheries Service to improve passage at the weir. The proposed project would remove the existing weir and reprofile the streambed using a roughened channel (Appendix E). Roughened channels are channels engineered to remain relatively stable using a framework of large boulders with a matrix of heterogeneous mix of cobbles, gravels, sands, and silts. Construction of the proposed roughened channel will involve mobilizing construction equipment to the work area, removing the existing Bonde Weir, delivering materials to the work area, constructing reprofiled channel, installing scour protection, demobilizing, and installing erosion control measures along the edges of the work area and access route. Temporary construction access to the site will be coordinated with Cities of Palo Alto and Menlo Park. Access through El Palo Alto Park from Palo Alto Avenue would likely require fewer disturbances to the stream banks and be less costly than access from the green space at the southern end of Alma Street. The project will restore the access route to pre‐project conditions. The project will be constructed between June and mid‐October when San Francisquito Creek is not conveying water and the streambed is dry and groundwater levels are relatively deep below the streambed. Rainfall events are relatively rare during this time of year and generally do not produce significant flow. Based on the historic conditions, NHC believes construction will not include dewatering and fish rescue and relocation. Excavation within the streambed will be relatively shallow and is unlikely to intercept groundwater, which will limit the need to control water. Dam removal will involve demolishing the existing dam while protecting the existing concrete slope protection and removing and disposing of debris from the project site. Construction equipment will likely include a small excavator with a hydraulic breaker attachment to demolish the dam and excavator to load trucks. Debris will be disposed at a landfill or other approved site. Preliminary material estimates indicate that about 400 cubic yards of material will excavated from the site and about 180 cubic yards of the excavated sand and gravel will be stockpiled and mixed with imported engineered streambed material to construct the roughened channel. About 600 cubic yards of material will be imported. Construction will likely occur over a period of about 6 weeks and will be scheduled to end prior to October 15, 2013. City of Palo Alto Page 3 The National Oceanic and Atmospheric Administration (NOAA), the San Francisquito Creek Joint Powers Authority (SFJPA), and Acterra all support the project (Attachment C). On May 28, 2013, the Parks and Recreation Commission reviewed the project and the park improvement ordinance and voted unanimously (5 - 0) to recommend that the Council approve the park improvement ordinance for this project. The Commission asked if the project would change the upstream or downstream flow in the creek. The project design engineer explained that the project will not affect water flow upstream or downstream. The Commission also asked if there would be long-term maintenance costs incurred by the City due to the project. The design engineer explained that the project is designed to be self-sustaining and there will not be any new maintenance costs caused by the project. The Commission also asked if the existing weir offered structural support to the Caltrans wall. The design engineer explained that the weir does not offer structural support. Timeline Construction is expected to continue for approximately eight weeks, beginning in June 2013 and be completed by October 15, 2013. Resource Impact The project is fully funded by San Mateo County Resource Conservation District via a grant from the State Coastal Conservancy. Policy Implications The proposed ordinance is consistent with Goal N-1 of the Comprehensive Plan, which encourages the management of Open Space in such a way as to protect our natural resources and provide a source of beauty and enjoyment for Palo Alto residents. The ordinance is also consistent with Goal N-4 of the Comprehensive Plan, which encourages water resources to be prudently managed as to sustain plant and animal life. Environmental Review This project is categorically exempt under California Environmental Quality Act (CEQA) guidelines; therefore, no environmental review is required. Attachments: Attachment A- Park Improvement Ordinance forBonde Weir Project (PDF) Attachment B- Project Description (PDF) Attachment C- Letters of Support for Bonde Weir Project (PDF) *NOT YET APPROVED* 130516 dm 00710210A Ordinance No. ______ Ordinance of the Council of the City of Palo Alto Approving and Adopting a Plan for Improvements to El Palo Alto Park The Council of the City of Palo Alto does ORDAIN as follows: SECTION 1. Findings. The City Council finds and declares that: (a) Article VIII of the Charter of the City of Palo Alto and Section 22.08.005 of the Palo Alto Municipal Code require that, before any substantial building, construction, reconstruction or development is commenced or approved, upon or with respect to any land held by the City for park purposes, the Council shall first cause to be prepared and by ordinance approve and adopt a plan therefor. (b) El Palo Alto Park is dedicated to park, playground and recreational space. (c) The City intends to authorize the construction of certain park improvements within El Palo Alto Park, as shown on the Bonde Fish Weir Passage Design Report (the “Design Report”), attached as Exhibit “A,” including: (1) Removal of a bank-to-bank concrete sill, known as the Bonde Weir, that acts as a barrier to fish passage under current conditions, and the replacement of the Bonde Weir with a re-graded and "roughened" channel; (2) Installation of scour protection and native plant erosion control measures along the edges of the work area and access route; and (3) Installation and construction of additional irrigation facilities to rapidly establish the new vegetation (the “Project”). (d) The improvements at El Palo Alto Park will include an area of the Park located in Palo Alto that spans the length of the San Francisquito Creek portion of the Park. (e) The Project will be constructed in a manner as to avoid protected trees and other sensitive natural resources, if any. In addition, the existing park uses will be restored following the completion of construction of the Project. (f) The Project is consistent with park and conservation purposes. (g) The Council desires to approve the Project, described above and as more specifically described in the Plan, attached hereto as Exhibit "A.” SECTION 2. The Council hereby approves the Design Report for the construction of the improvements at El Palo Alto Park, and it hereby adopts the Design *NOT YET APPROVED* 130516 dm 00710210A Report, attached hereto as Exhibit "A,” as part of the official plan for the construction of the park improvements at El Palo Alto Park. SECTION 3. The Council finds that the San Mateo Resource Conservation District has determined the Project (to construct the facilities at El Palo Alto Park) is categorically exempt under the California Environmental Quality Act. SECTION 4. This ordinance shall be effective on the thirty-first day after the date of its adoption. INTRODUCED: PASSED: AYES: NOES: ABSENT: ABSTENTIONS: ATTEST: __________________________ ____________________________ City Clerk Mayor APPROVED AS TO FORM: APPROVED: __________________________ ____________________________ Senior Asst. City Attorney City Manager ____________________________ Director of Community Services ____________________________ Director of Administrative Services Page 1 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Bonde Weir Fish Passage and Channel Stabilization Project Project Description San Francisquito Creek Palo Alto & Menlo Park, CA February 2013 Summary: The Bonde Weir Fish Passage and Channel Stabilization Project (or project) is located in San Francisquito Creek in the cities of Palo Alto and Menlo Park. The project site occupies a portion of the border between Menlo Park and Palo Alto about 1.7 miles southwest of U.S. Highway 101 near El Camino Real Bridge (Appendix A). The project proposes to remove a bank-to-bank concrete sill, known as the Bonde Weir, that acts as a barrier to fish passage under current conditions and replace it with a re-graded and "roughened" channel. This channel type uses engineered streambed materials to maintain and improve stability over a wide range of streamflows while providing vastly improved conditions for fish migration and movement. In particular, the project is intended to benefit steelhead trout (Oncorhynchus mykiss), as the San Francisquito Creek watershed provides habitat for this species. The watershed is part of the Central California Coast steelhead Evolutionarily Significant Unit in which steelhead are considered "threatened" under the federal Endangered Species Act. The project also will improve channel stability over existing conditions. Page 2 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Need for the project: The Bonde Weir has been recognized by local biologists and state and federal resource agencies as an impediment to steelhead passage for at least ten years. The deteriorating condition of the weir may also pose a risk to channel stability. Under low flow conditions, stream flow pools upstream from the weir resulting in a lack of flow over the weir or in sheet flow unfavorable to migrating fish due to inadequate water depth. Under higher flow conditions, water velocity may further limit migration opportunities. The majority of the watershed's spawning and rearing habitat occurs in San Francisquito Creek and its tributaries upstream from the weir, suggesting that limits to in-migrating steelhead have substantial effects on the steelhead population. Further, under low flow conditions, fish may be prevented or delayed from moving downstream to favorable habitats or to out-migrate, possibly resulting in mortality. The project will greatly improve passage conditions and opportunities to successfully complete the steelhead life history. The remainder of this project description includes sections that characterize existing conditions at the project site, elements of the project, sequence and schedule of proposed activities, staging areas and access, related permits and measures to avoid impacts. The description has been prepared by the San Mateo County Resource Conservation District (RCD) on behalf of the several organizations partnering to implement the project to provide information to reviewing agencies and the interested public. Questions or comments on any aspect of the project are welcomed and may be addressed to the RCD staff listed at the end of this document. Existing site conditions: The Bonde Weir is located in San Francisquito Creek where the creek passes through El Palo Alto Park. The weir is about 15 feet downstream from the pedestrian bridge crossing and approximately 80 feet downstream from the bridge over which the Caltrain tracks cross the creek. It consists of an 11 foot long and 45 foot wide concrete sill. The weir is located near the midpoint of a right trending bend (looking downstream) in the creek. The creek upstream of the weir has trapezoidal shape with a bed width of about 20 feet, a right bank (looking downstream) side slope of about 0.6 feet horizontal to 1 foot vertical (0.6:1), and a left bank side slope of 0.8:1. The creek bed is about 20 to 25 feet below the adjacent top of banks. A concrete wall along the right bank (looking downstream) extends from 3 feet downstream of the weir to about 150 feet upstream. The left bank is composed of native material. Sheet C2 from the design plans (Appendix B) shows the site topography and planimetric features. A view of the creek looking upstream of the pedestrian bridge is shown in Figure [1]. Page 3 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Figure 1: Looking Upstream from Bonde Weir. The sill slopes downstream at 4.8 feet horizontal to 1 foot vertical (4.8:1, or about 20 percent). The low point along the weir crest is at elevation 46.6 feet (all elevations are relative to USC&GS BM H7) and the downstream end of the weir is at elevation 44.5 feet. Figures [2], [3], and [4] show frontal, side, and top views of the weir, respectively. Page 4 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Figure 2: Bonde Weir looking from downstream to upstream. Page 5 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Page 6 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Figure 3: Bonde Weir looking from the right bank above. Figure 4: Bonde Weir looking from upstream to downstream from the pedestrian bridge above. A pool forms upstream of the weir during low flows. The pool characteristics are influenced by several factors, including the hydraulic characteristics of stream bends, which typically induce scour along the outside toe of the bend. At the weir, local scour also occurs in the lee of a sackcrete storm drain outlet apron and at the backwater resulting from the weir. Using the weir crest to define the pool surface, the pool extends more than 160 feet upstream of the weir. The deepest part of the pool is along the downstream end of the drainage outlet, where the substrate is about 4 feet below the lowest point of the weir crest. Figure [5] shows the storm drain outlet. Page 7 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Figure 5: Storm drain outfall on the left bank just upstream from Bonde Weir. Downstream of the weir, the channel width increases to about 25 feet. The adjacent banks range in slope from 5:1 to 2:1. Toward the top of the adjacent banks, slope ranges from 2:1 to 1:1. Figure [6] shows a view of the creek downstream of the pedestrian bridge. Page 8 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Figure 6: San Fransquito Creek Channel looking downstream from Bonde Weir. Concrete rubble and large rock are found in the bed immediately downstream of the weir. The rubble does not appear to be a significant portion of the bed and will have to be removed from the site. The exact volume of rubble to be removed will likely be less than 50 tons. This rubble will be disposed of at an approved waste facility. The large rock will be evaluated by the field engineer to ensure it meets hardness criteria and will likely be included in the proposed channel design. Page 9 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX Project elements and activities: The project will remove the existing weir, add scour protection to the retaining wall at the Caltrain bridge, re-profile the channel using engineered streambed materials, and stabilize and re-vegetate adjacent stream banks. The following describes each of these activities in greater detail. Sheets C2 and C3 in Appendix B provide plan and profile views of each of the project elements. Remove existing weir: In this part of the project, heavy equipment will be used to demolish the existing weir and remove the associated debris. As-built design drawings of the weir were unattainable and the exact dimensions of the weir are unknown. However, the weir is not believed to be attached to the concrete wall protecting the foot of the pedestrian and Caltrain bridges. Concrete rubble and limited amounts of poor quality rock will be removed from the site during this phase and disposed of at an approved waste facility. It is expected about 400 cubic yards of material will be removed from the site. Excavate project site: After the weir has been removed, the channel will be excavated down to 3 feet below the finished grade along the 100 lineal feet of channel where the roughened channel will be located. Excavation will occur between streambanks and will maintain a slope of 1.5H:1V or flatter between excavated surfaces and existing surfaces to be undisturbed. The excavated material will be sorted and stockpiled on-site. This material will be used in creating the engineered streambed material in later construction stages. Add Caltrain bridge scour protection: Approximately 65 lineal feet of rock riprap will be placed along the left bank of the channel. The rock will be placed along the toe of the concrete wall to protect the wall from erosion, and will extend downstream of the wall about 25 feet. The rock will be placed at a 3 foot thickness and result in about 0.5-1CY of rock per lineal foot of protection. Re-profile using engineered materials and rock buttresses: The creek channel will be re-profiled between a location about 20 feet upstream of the existing weir's upper extent and a location about 80 feet downstream of the existing weir's lower extent. The roughened channel will be about 100 feet long and will have a slope of about 1 percent. The roughened channel construction includes importing various sizes of quarried rock, cobble and gravel and mixing these Engineered Streambed Materials (ESM) with fines found on site. The heterogeneous mix of ESM forms a tight structure that minimizes loss of streamflow into the bed and potential for scour during high flow events. Hydraulic modeling completed by Northwest Hydraulic Consultants (2012) indicates that water depths and velocities in the roughened channel will be comparable to those found in proximate riffle sections of the creek. The model results show that flow upstream from the project site will be unaffected by the channel reconfiguration. Page 10 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX After placement of the ESM, the contractor will install buttress/framework material, boulder clusters, and engineered streambed materials per the design, and as directed by the engineer. The field engineer will be onsite to verify the grade of the rock buttress material and the gradation of the ESM to ensure it is placed properly. The contractor will likely set the rock buttresses at the proper grade and fill the ramp between buttresses with 1 foot compacted lifts of ESM. Boulder clusters will be placed as appropriate. Stabilize and re-vegetate banks: Disturbed areas will be replanted with native plants sourced as much as possible from the San Francisquito Creek watershed. An estimated 2,000 square foot area will be temporarily disturbed and will need to be revegetated. Plantings will be watered and maintained after the construction period to assure their survival. Temporary erosion control measures will be used to maintain soil stability until plantings are established. Please see the Basis of Design Report (Appendix C) by Northwest Hydraulics for additional detail into the engineers rational for proposed project designs. Sequence and schedule: Construction is expected to last approximately eight weeks, beginning as early as June 2013 and completed by October 15, 2013. Major tasks are listed below: Establish staging and access areas Mobilize equipment Survey layout Install temporary erosion control measures Install traffic control and signage Establish staging and equipment access areas Removal and offhaul weir Excavate channel, and salvage and stockpile bed material Imported ESM Construct roughened channel Restore and revegetate temporarily disturbed areas Staging areas and access: Equipment will access the site as shown in sheet G2 of Appendix B Equipment access will occur via a path between Palo Alto Avenue and the south side of the creek. The access route will follow the route of an existing 8 foot wide bike path and will terminate at the least steep portion of the stream bank. The access route will be no wider than 11 feet, with unlimited overhead clearance. Staging and materials access will be provided on the north side of the creek in an area east of the Caltrain right of way in El Palo Alto Park. The Park is managed by the City of Menlo Park. This Page 11 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX staging area will encompass approximately 8,000 square feet. All ESM will be delivered via a route marked by the City of Menlo Park. Avoidance of impacts: The project has been designed to minimize impacts to the site and to fish and wildlife potentially utilizing the project area. The following specific actions will be incorporated into the project description to reduce construction-related effects on vegetation and landscape, water quality, and public access. Vegetation and landscape: The portion of the equipment access route outside of the existing bicycle path will be covered with 10 inches of mulch and overlaid with plywood or matting to protect tree roots. At locations where the access route requires excavation, an air spade or hydro excavation will be used to expose roots along the edge of the proposed route. The roots will be cleanly cut using a chainsaw or handsaw to prevent excavation of the access route from ripping roots out of the ground. The access route will be established with 10 feet of clearance from trees where possible. All trees within 6 feet of the access route will be protected (e.g., with snow fencing and plywood when deemed necessary). No trees will be removed on the Palo Alto side of the park; however, trees limbs will be removed by the urban forester for the City to allow for equipment access, as necessary. Several small shrubs that are in the access route will either be transplanted or replanted, and numerous small trees (i.e., less than 2-inches diameter at breast height [dBH]) on the Menlo Park side will be removed. Areas where vegetation will be removed to facilitate construction will be re-vegetated as part of the project in accordance with Palo Alto’s and Menlo Park’s park improvement ordinances. Construction will occur in the dry season, minimizing the potential for erosion. Additionally, erosion control measures, such as fiber rolls, jute mats and mulch will be installed to further reduce the risk of sedimentation resulting from project activities. The project site, including the equipment access road and staging area, will be re-vegetated and the plantings will be maintained to ensure their survival after the construction phase. Acterra, a local environmental non-profit in Silicon Valley, is currently active in native plant revegetation efforts and will be hired to provide their services in conjunction with this project’s need for revegetation and erosion control in disturbed areas. Their volunteer network will participate in implementing the project, and will assist in monitoring and maintaining the project area in the park after the construction activities are complete. Water Quality: During the proposed construction period, the creek is typically dry. Therefore, stream dewatering and fish relocation/exclusion is not expected to be necessary. If the creek Page 12 of 12 San Mateo County www.sanmateorcd.org 625 Miramontes Street, Suite 103, Half Moon Bay, CA 94019 650.712.7765 650.726.0494 | PHONE | FAX experiences flow during the construction period, a qualified biologist will be retained to avoid impacts to aquatic species. Public Access: All equipment will access the site on designated access routes and will be staged in the designated staging area. Signage and traffic control will be accomplished in accordance with Palo Alto and Menlo Park standards along the bike path and surface streets. Construction will be limited to normal daylight hours. Permits: The project will require the following permits: Clean Water Act, Section 404 Permit, U.S. Army Corps of Engineers Clean Water Act, Section 401 Water Quality Certification, San Francisco Regional Water Quality Control Board Lake or Streambed Alteration Agreement, California Department of Fish and Wildlife Biological Opinion, National Marine Fisheries Service Letter of Concurrence, U.S. Fish and Wildlife Service (possible) Park Improvement Ordinance, Tree Permit, and Encroachment Permit, City of Palo Alto Encroachment Permit, City of Menlo Park Contact Information: Kellyx Nelson, Executive Director Resource Conservation District Kellyx@sanmateorcd.org 650.712.7765 x102 Joe Issel, Conservation Assistant Resource Conservation District Joe@sanmateorcd.org 650.712.7765 x106 Bonde Weir Fish Passage: Basis of Design Report San Mateo Resource Conservation District September 7, 2012 water resource specialists Bonde Weir Fish Passage: Basis of Design Report September 7, 2012 Prepared for: San Mateo Resource Conservation District 625 Miramontes St # 103 Half Moon Bay, CA 94019 Phone: 650‐712‐7765 Contact: Kellyx Nelson Prepared by: northwest hydraulic consultants 3950 Industrial Blvd, Suite 100C West Sacramento, California 95691 Phone: 916.371.7400 Contact: Joey Howard, P.E. Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report i TABLE OF CONTENTS 1.0 Introduction ...................................................................................................................................... 1 2.0 Project Description ............................................................................................................................ 1 2.1 Project Objective ........................................................................................................................... 1 2.2 Existing Conditions ........................................................................................................................ 1 2.3 Project Conditions ......................................................................................................................... 7 3.0 Topographic Survey and Datums ...................................................................................................... 7 4.0 Hydrologic Analysis ........................................................................................................................... 7 4.1 Flow Frequency Analysis ............................................................................................................... 7 4.2 Fish Passage Flows ........................................................................................................................ 8 5.0 Hydraulic Analyses ............................................................................................................................ 9 5.1 Existing Conditions Model ............................................................................................................ 9 5.2 Project Conditions Model ........................................................................................................... 10 5.3 Extreme Flows ............................................................................................................................. 10 5.4 Fish Migration Flows ................................................................................................................... 10 6.0 Engineered Streambed Material ..................................................................................................... 14 7.0 Implementation considerations ...................................................................................................... 14 8.0 References ...................................................................................................................................... 15 Appendix A: Hydrology ............................................................................................................................... 17 Appendix B: HEC‐RAS Model Results .......................................................................................................... 18 Appendix C: Rock Sizing Calculations .......................................................................................................... 31 Appendix D: 30% Design Drawings ............................................................................................................. 33 LIST OF FIGURES Figure 2‐1: Site Map ...................................................................................................................................... 3 Figure 2‐2: San Francisquito Creek Upstream of the Alma St Pedestrian Bridge ......................................... 4 Figure 2‐3: Bonde Weir viewed from downstream ...................................................................................... 4 Figure 2‐4: Bonde Weir Crest ........................................................................................................................ 5 Figure 2‐5: Bonde Weir ................................................................................................................................. 5 Figure 2‐6: Bonde Weir and Storm Drain Outlet .......................................................................................... 6 Figure 2‐7: San Francisquito Creek downstream of the Alma St Pedestrian bridge ..................................... 6 Figure 5‐1: 100 Year Flood Profiles for Existing and Project Conditions..................................................... 10 Figure 5‐2: HEC‐RAS Computer Velocities .................................................................................................. 12 Figure 5‐3: HEC‐RAS Computer Depths....................................................................................................... 13 LIST OF TABLES Table 4‐1: USGS Gage Stations in the San Francisquito Creek Drainage Basin ............................................. 8 Table 4‐2: Flow Summary Table near the Bonde Weir ................................................................................. 8 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report ii Table 4‐3: Fish Passage Flow Criteria ............................................................................................................ 9 Table 5‐1: Minimum Required Flow Depth ................................................................................................. 11 Table 5‐2: Maximum Permissible Velocity (CDFG, 1998) ........................................................................... 11 Table 5‐3: Recommended Maximum Energy Dissipation Factors (CDFG, 2009) ........................................ 11 Table 5‐4: Design Comparison with Criteria ............................................................................................... 14 Table 6‐1: Engineered Streambed Material Design Gradation ................................................................... 14 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 1 BONDE WEIR FISH PASSAGE PROJECT: BASIS OF DESIGN REPORT 1.0 INTRODUCTION Northwest Hydraulic Consultants (nhc) is preparing the design for a fish passage improvement project at the Bonde Weir in San Francisquito Creek for the San Mateo County Resource Conservation District (RCD). This report briefly describes the physical setting, project considerations, and proposed design. The Bonde Weir was recognized by the San Francisquito Creek Watershed Council – Steelhead Task Force ‐ as a barrier to steelhead (Oncorhynchus mykiss) passage. At times, in‐migrating adult as well as out‐migrating smolt steelhead trout may be delayed or prevented from passing the weir. The San Mateo County RCD, the project sponsor, received a grant from the mitigation funds generated by the Bay Bridge Project and administered by the National Marine Fisheries Service to improve passage at the weir. 2.0 PROJECT DESCRIPTION 2.1 Project Objective The broad goal for the project is to improve the hydraulic characteristics for fish passage at the existing Bonde Weir site while protecting existing infrastructure. 2.2 Existing Conditions The Bonde Weir crosses San Francisquito Creek about about 15 feet downstream of the Alma Street Bicycle/Pedestrian Bridge and 80 feet downstream of a Caltrain Bridge near El Palo Alto Park. The weir is located near the midpoint of a right trending bend (looking downstream) in the creek. The creek upstream of the weir has a bed width of 20 feet, a right bank side slope of about 0.6 feet horizontal to 1 foot vertical, and a left bank side slope of 0.8 feet horizontal to 1 foot vertical. The creek bed is about 20 to 25 feet below the adjacent ground. A concrete wall along the right bank (looking downstream) extends from 3 feet downstream of the weir upstream about 150 feet. The left bank is composed of native material. Figure 2‐1 shows the site topography and planimetric features. A view of the creek looking upstream of the Alma Street Bicycle/Pedestrian Bridge is shown in Figure 2‐2. The weir consists of an 11 foot long and 45 foot wide concrete sill. The sill slopes downstream at 4.8 feet horizontal to 1 foot vertical (20 percent). The low point along the weir crest is at elevation 46.6 feet (all elevations are relative to USC&GS BM H7‐ See Section 3.0) and the downstream end of the weir is at elevation 44.5 feet. Figure 2‐3, 2‐4, and 2‐5 show frontal, side, and top views of the weir, respectively. A pool forms upstream of the weir during low flows. The pool characteristics are influenced by several factors. These factors include the hydraulic characteristics of stream bends, which typically induce scour along the outside toe of the bend, local scour in the lee of a sackcrete storm drain outlet apron, and the backwater resulting from the weir. Using the weir crest to define the pool surface, the pool extends more than 160 feet upstream of the weir. The deepest part of the pool is along the downstream end of the sackcrete drainage outlet structure. The minimum pool elevation surveyed November of 2007 was Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 2 at 44.7 feet. This elevation is 4 feet below the low point on the weir crest. Figure 2‐6 shows the storm drain outlet and the outlet apron. Downstream of the weir, the creek is less confined than the upstream reach. The channel width increases from 20 feet to about 25 feet. The channel banks near the bed range in slope from 5 feet horizontal to 1 foot vertical to 2 feet horizontal to 1 foot vertical. The upper portion of the banks range in slope from 2 feet horizontal to 1 foot vertical to 1 foot horizontal to 1 foot vertical. Figure 2‐7 shows a view of the creek downstream of the pedestrian bridge. Bonde Weir Fish Ladder Project Potential Construction Access Routes northwest hydraulic consultants project no. 500045 August 2012 Scale - LEGEND SF BAY REFERENCE MAP CA State Plane, Zone III horz. datum: NAD 83 horz. units: feet Redwood City Menlo Park Palo Alto Atherton San Carlos Woodside East Palo Alto Stanford North Fair Oaks Emerald Lake Hills Foster City West Menlo Park Belmont Fremont §¨¦280 tu101 UV84 UV84 Figure 1: Project Site Location Bonde Weir Fish Ladder Project nhc August 2012 [j El Camino Real Bridge CalTrain Bridge Fishway Construction Site @ Bonde Weir Alma WillowAlma El Camino Real High Alto Everett Emerson 15 HawthorneAlma Palo Alto Lytton 33 Harvard Poe Creek Ramona Bryant Waverley RuthvenLinfield Cornell Cambridge Cowper Sherwood Claremont Sand Hill Creek Palo Alto 1:3,600 ©1 inch = 300 feet Data Sources: ESRI StreetMap USA Roads, 2005. USDA-FSA Color Aerial Photography, 8/13/2009. San Francisquito Creek Fishway Construction Site @ Bonde Weir El Palo Alto Historic Tree[j 0 300 600150Feet Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 4 Figure 2-2: San Francisquito Creek Upstream of the Alma St Pedestrian Bridge Figure 2-3: Bonde Weir viewed from downstream Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 5 Figure 2-4: Bonde Weir Crest Figure 2-5: Bonde Weir Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 6 Figure 2-6: Bonde Weir and Storm Drain Outlet Figure 2-7: San Francisquito Creek downstream of the Alma St Pedestrian bridge Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 7 2.3 Project Conditions The proposed project would remove the existing weir and reprofile the streambed using a roughened channel (Appendix E). Roughened channels are channels engineered to remain relatively stable using a framework of large boulders with a matrix of heterogeneous mix of cobbles, gravels, sands, and silts. The roughened channel would have a grade of about 1%. The upstream section of the roughened channel would originate about 15 feet upstream of the current location of the weir, and would extend downstream about 70 feet past the current location of the weir. The roughened channel would be composed of engineered streambed material (Section 6). Angular rock riprap would be placed along the toe of the existing wall to prevent toe scour. The roughened channel is designed to replace the existing weir by acting as a grade control structure preventing undermining of the concrete wall and preventing channel incision from migrating upstream. The reprofiling of the channel helps reduce the abrupt hydraulic disruption and potential local scour caused by this disruption. Appendix E provides 30% conceptual design drawings of the proposed project design. 3.0 TOPOGRAPHIC SURVEY AND DATUMS BGK Engineering under contract with NHC conducted a topographic survey of the site (including the creek, the adjacent area, and the weir) in November, 2007. The survey extended about 150 feet downstream of the weir and about 50 feet upstream of the weir from top of left bank to top of right bank. Survey elevations were tied into USC&GS benchmark H7 (BM H7). BM H7 is a brass disc in the Northwesterly concrete abutment for the Caltrain Railroad bridge over the San Francisquito Creek located just upstream of the site. The BM is stamped with an elevation of 72.123 feet. All elevations reported within this document are based on this elevation. 4.0 HYDROLOGIC ANALYSIS To develop design parameters for the fish passage improvement project, NHC estimated peak flood flows and flow durations. The results are described in the following. 4.1 Flow Frequency Analysis Flow frequency analyses and flow duration analyses were conducted using data collected at the U.S. Geological Survey (USGS) gage on San Francisquito Creek at Stanford University (Gage 1116400). This gage, located on the Stanford Golf Course upstream of Junipero Serra Boulevard, provides the best long‐ term record of flow in San Francisquito Creek with measurements from 1931 to 1941 and from 1951 to present. The gage has a tributary area of 37.5 square miles composed of areas within the Santa Cruz Mountains and Bay Foothills. . Stream gages that have been operated on San Francisquito Creek and its tributaries by the USGS are summarized in Table 4‐1. Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 8 Table 4-1: USGS Gage Stations in the San Francisquito Creek Drainage Basin Gage Name Gage Number Period of Record Area (mi2) River Mile 1 At Searsville Dam (staff gage on spillway crest) None 1892‐1913 – 12.7 At Stanford University 11164500 1931‐41; 1950 to present 37.5 7.6 At Menlo Park 11165000 1931‐1941 38.3 5.4 At Palo Alto 11165500 1934‐36 38.4 4.6 Los Trancos Ck near Stanford University 11163000 1930‐41 – – Los Trancos Tributary near Stanford University 11163200 1958‐66 0.42 – Los Trancos Ck at Stanford University 11163500 1930‐41 7.46 – Peak flows were calculated from an analysis of annual maxima at the USGS Gage Number 1116400. Flood frequency statistics were calculated for the gage using the procedures recommended by the USGS and described in Bulletin 17B (IACWD, 1982). A flood frequency plot for this gage is included in Appendix A. Peak flows expected to occur at 2‐, 10‐, 25‐, 50‐, and 100‐year return periods were calculated at USGS Gage were used to estimate the flows at the Bonde Weir and are listed in Table 4‐2. The effective 100‐ year peak flood flow calculated in this analysis is essentially the same as the flow listed in the Flood Insurance Study (FIS) for Menlo Park at San Francisquito Creek at El Camino Real (FEMA, 1999). The effective FIS cites a flow of 8,280 cubic feet per second (cfs) for a drainage area of 40.6 square miles at El Camino Real. Table 4-2: Flow Summary Table near the Bonde Weir Characteristic San Francisquito Crk at Stanford University (11164500) Drainage Basin Area 37.5 mi2 100‐year peak flow 8,272 cfs 25‐year peak flow 6,157 cfs 10‐year peak flow 4,595 cfs 2‐year peak flow 1,576 cfs 4.2 Fish Passage Flows The California Salmonid Stream Habitat Restoration Manual (CDFG, 1998) identifies the 1% and 95% exceedance flows, based on a duration analysis of mean daily flows, as the upper and lower bounds for Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 9 fish passage analyses for the target fish species and life stages. The fish migration flows at the Bonde Weir were calculated from USGS gage Number 1116400. Exceedance flows are summarized in Table 4‐3. As noted in Table 4‐3, we suggest adopting an alternative minimum flow of 1 cfs and 3 cfs, respectively, for the juvenile and adult fish migration analysis. The data and program output for the fish migration flows are included in Appendix A. Table 4-3: Fish Passage Flow Criteria Description Flow rate (cfs) 1% exceedence flow High Flow Adult Salmonid 470 10% exceedence flow High Flow for Juvenile Salmonid 40 50% exceedence flow Low Flow Adult Salmonid (3 cfs alt min flow) 0.8 95% exceedence flow Low Flow Juvenile Salmonids (1 cfs alt min flow) <0.1 5.0 HYDRAULIC ANALYSES NHC conducted hydraulic analyses using HEC‐RAS version 4.1.0 (USACE, 2010) to characterize existing and project hydraulic conditions. HEC‐RAS is a one‐dimensional model that is capable of computing average channel velocities and water surface profiles. HEC‐RAS is useful in estimating hydraulic characteristics and water surface profiles during moderate to high flows. It can also be used to estimate hydraulic characteristics during low flow, but is not capable of simulating microhydraulics in roughened channels. Sections 5.1 and 5.2 describe the existing and project conditions model development. Section 5.3 describes the model results for extreme flows, while Section 5.4 describes model results for fish passage flows. Results from HEC‐RAS analysis are included in Appendix B. 5.1 Existing Conditions Model The downstream boundary of the HEC‐RAS model is about 130 feet downstream of the weir the model extends about 50 feet upstream of the weir. The basic features of the model include: Through this reach, the channel section and slope provide the downstream hydraulic control for stream flow. At low flows the riffle crest 50 feet downstream of the weir serves as a control that causes flow to backup to the base of the weir. Under the existing condition, the steep smooth weir surface efficiently conveys flows over the weir. These flows are characterized by high velocities and are supercritical. The downstream boundary condition is computed as a normal depth with friction slope of 0.002. The concrete weir was simulated in the model geometry within HEC‐RAS. Model cross section spacing ranges from 5 to 50 feet with a narrower spacing near the weir. The roughness coefficient ("Manning’s n") across the existing concrete weir was estimated to be 0.025 under the existing conditions. Manning’s n in the channel for the existing was estimated to be 0.035. The overbank Manning’s n was estimated to be 0.05. Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 10 Model runs were performed using a subcritical flow regime to identify peak water surface levels. Application of the subcritical flow regime to calculate water surface profiles is consistent with FEMA flood hazard modeling guidelines to determine flood profiles (FEMA, 2003). Profiles and hydraulic calculations for flood flows were compiled for the 10‐, 25‐ and 100‐year flood events. 5.2 Project Conditions Model The project conditions HEC‐RAS model used the same model extents, cross‐section locations, and boundary conditions as the existing condition model. Modifications to the project conditions model included: Adjustment of the cross‐section geometry to create a channel approximately 40 feet wide with invert elevations producing a 1% slope through the area of the proposed roughened channel. Increasing the Manning’s n value of the cross‐sections within the roughened channel to 0.05. 5.3 Extreme Flows The project’s influence on peak water surface elevation (i.e., stage) during a 100‐year flood event was estimated using HEC‐RAS. Water surface profiles for existing conditions and with the project in place were calculated and compared. The 100‐year peak flow water surface profiles for the existing and proposed conditions are shown in Figure 5‐1. The project shows water surface elevations downstream and upstream of the project area are likely to be unaffected. Water surface elevations may vary between existing and project conditions within the project reach as a result of a hydraulic jump, which currently exists at the weir, moving downstream about 30 feet. Figure 5-1: 100 Year Flood Profiles for Existing and Project Conditions 5.4 Fish Migration Flows Adult steelhead typically migrate to spawn between late fall and early spring, with a peak between January and March. Downstream migration of juveniles usually occurs between about February and April. The roughened channel was designed to simulate adjacent stream and hydraulic conditions and 0 50 100 150 20042 44 46 48 50 52 54 56 58 60 Main Channel Distance (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 100-Year - Project-rev Crit 100-Year - Exist-rev Crit 100-Year - Project-rev Ground Ground BONDE CENTERLINE BONDE CENTERLINE Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 11 reprofile the reach where the Bonde Weir currently occurs, without affecting the upstream or downstream bed profile. The following design parameters were used to determine if the project would provide fish passage: maximum average velocity, minimum flow depth, maximum hydraulic drop height, and maximum turbulence. These design parameters are further segregated by life stage and species. Minimum flow depth is primarily a function of body size, which is characterized by life stage and species. Table 5‐1 shows the minimum flow depths. Table 5-1: Minimum Required Flow Depth Species/Lifestage Minimum flow depth, ft Adult Anadromous Salmonid 1.0 Adult Non‐Anadromous Salmonid 0.67 Juvenile Salmonid 0.5 Design criteria for maximum average velocities are categorized first by life stage and by the distance that the average velocity occurs. The distances are intended to match the swimming characteristics of adult fishes where maximum swim speeds for adult salmonids and non‐salmonids are generally characterized into three groups: burst, prolonged, and sustained. Burst speeds generally occur for less than 20 seconds, prolonged speeds generally range from about 20 seconds to about 200 minutes, and sustained speeds may occur for an indefinite period that exceeds 200 minutes. The maximum average water velocity for juveniles is 1 feet per second (fps). Table 5‐2 shows design criteria for adults. Table 5-2: Maximum Permissible Velocity (CDFG, 1998) Passage Distance (Culvert Length) Ft Adult Non‐Anadromous Salmonids, fps Adult Anadromous Salmonids, fps < 60 4 6 60 – 100 4 5 100 – 200 3 4 200 – 300 2 3 > 300 2 2 Turbulence, defined herein as irregular and random fluctuations in local velocity and pressure, can impair fishes’ ability to move upstream. Turbulent flow may disorient fish or reduce leaping abilities by aerating the flow and reducing stream flow density. The California Department of Fish and Game (DFG) and the National Marine Fisheries Service (NMFS) use the energy dissipation factor (EDF) to characterize turbulence. Maximum permissible EDFs vary with the type of flow conditions. Table 5‐3: Recommended Maximum Energy Dissipation Factors (CDFG, 2009) lists EDF equations for sloping channels and the maximum permissible EDF for adult steelhead and resident trout. Table 5-3: Recommended Maximum Energy Dissipation Factors (CDFG, 2009) Flow Condition EDF Eqn. Max EDF Adult Steelhead Max EDF Adult Resident Trout Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 12 ft‐lbs/s/ft3 ft‐lbs/s/ft3 Sloping Channel VS 6.0 4.5 Hydraulic characteristics for fish passage were assessed for flows ranging from 1 cfs up to 470 cfs (Table 4‐3). Figure 5‐2 shows modeled in‐channel velocities. The reprofiled channel reach starts near distance 60 and ends near distance 140 in the figures below. Modeled cross section average velocities are less than 6 fps through the project the entire range of modeled flows. Since HEC‐RAS cannot account for the presence of in‐channel features such as boulder clusters or variation in velocity across a section over various depths, there are likely to be pockets and areas of slightly lesser and greater velocities as those shown in Figure 5‐2. Figure 5-2: HEC-RAS Computer Velocities Modeled flow depths were the lowest at the minimum modeled flow of 1 cfs. Flow depths were about 1 foot or greater at flows of 25 cfs and greater. It should be noted that channel geometry simulated in the model is simplified and represents the roughened channel as a level bed. Actual conditions on the roughened channel will be complex, allowing for smaller pockets of increased depth to exist. 0 50 100 150 2000 1 2 3 4 5 6 Main Channel Distance (ft) Ve l C h n l ( f t / s ) Legend Vel Chnl Q=470cfs Vel Chnl Q=400cfs Vel Chnl Q=300cfs Vel Chnl Q=200cfs Vel Chnl Q=100cfs Vel Chnl Q=50cfs Vel Chnl Q=40cfs Vel Chnl Q=25cfs Vel Chnl Q=3cfs Vel Chnl Q=1cfs BONDE CENTERLINE BONDE CENTERLINE Project Extents Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 13 Figure 5-3: HEC-RAS Computer Depths Fish passage performance along the project reach was compared with DFG and NMFS stream simulation and hydraulic criteria. A summary of DFG and NMFS fish passage criteria are listed in Table 5‐4. This comparison shows that computed design velocities meet criteria to allow both juvenile and adult fish passage. Flow depth criterion is met for the adult fish when the flow exceeds 25 cfs, but do not meet criteria down to the 3 cfs minimum design flow. Similarly, the flow depth criterion is not met for juvenile for flow rates between 1‐3 cfs, but is met for flows above 3 cfs. The energy dissipation factor is met for both juvenile and adult passage. It is important to note that due to the lack of a defined low flow channel that depths in sections of downstream reaches are unlikely to meet fish passage criteria at flows less than about 25 cfs. 0 50 100 150 2000 1 2 3 4 5 6 Main Channel Distance (ft) Ma x C h l D p t h ( f t ) Legend Max Chl Dpth Q=470cfs Max Chl Dpth Q=400cfs Max Chl Dpth Q=300cfs Max Chl Dpth Q=200cfs Max Chl Dpth Q=100cfs Max Chl Dpth Q=50cfs Max Chl Dpth Q=40cfs Max Chl Dpth Q=25cfs Max Chl Dpth Q=3cfs Max Chl Dpth Q=1cfs BONDE CENTERLINE BONDE CENTERLINE Project Extents Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 14 Table 5-4: Design Comparison with Criteria Design Condition Calculated Comparison with Criteria Velocity (Adult Anadromous Salmonid) <6fps Within Criteria Velocity (Juvenile Anadromous Salmonid) <3.5 fps Estimated to be within Criteria along channel margins and near boundary layer Flow Depth (Adult Anadromous Salmonid) 1ft‐4 ft (Q>25 cfs) <1ft (Q<25 cfs) Not Within Criteria Flow Depth (Juvenile Anadromous Salmonid) >0.5 ft when Q≥3cfs 0.3 ft @ 1cfs Not Within Criteria EDF <4lb/ft2/s Within Criteria 6.0 ENGINEERED STREAMBED MATERIAL The roughened channel will be constructed using engineered streambed materials (ESM). ESM will include a heterogeneous mix of material that is intended to form a tight structure that will minimize subsurface flow, prevent loss of smaller particles within the matrix, and remain relatively stable during extreme flood events. Inspection of native streambed material near the project site suggests that sediment supply into this reach ranges from fine wash load to small boulders (less than about 8 inches). Estimates for ESM were made using California Department of Fish and Game procedures. Calculations are provided in Appendix C. NHC proposes to use the ESM gradation shown in Table 6‐1 Table 6-1: Engineered Streambed Material Design Gradation PERCENT OF MIX ROCK SIZE, ft min max 16% 2.5 4.0 34% 1.0 2.5 34% 0.06 1.0 9% 0.01 0.06 7% SAND/SILT 7.0 IMPLEMENTATION CONSIDERATIONS The proposed fish passage structure is not anticipated to induce morphologic change that will negatively affect the stream banks, profile, adjacent properties, or infrastructure. The project is not expected to produce excessive degradation (i.e., downcutting by erosion) or aggradation upstream or downstream of the project area. Flow downstream of the project area is subcritical (downstream dependent) and should not be affected by the upstream changes. The results of the HEC‐RAS modeling show flow at Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 15 comparable depths and velocities under both existing and project conditions. The 0.01 ft/ft (1%) slope of the project is fairly representative of local bed slopes in riffle sections of the stream. The upstream edge of the project was found to be under critical flow conditions for both the existing and project conditions. This indicates that flow upstream of the project site will be unaffected by changing hydraulics through the project reach. 8.0 CONSTRUCTION ACTIVITIES Construction of the proposed roughened channel will involve mobilizing construction equipment to the work area, removing the existing Bonde Weir, delivering materials to the work area, constructing reprofiled channel, installing scour protection, demobilizing, and installing erosion control measures along the edges of the work area and access route. Temporary construction access to the site will be coordinated with Cities of Palo Alto and Menlo Park. Access through El Palo Alto Park from Palo Alto Avenue would likely require fewer disturbances to the stream banks and be less costly than access from the green space at the southerly end of Alma Street. An access ramp from Creek Drive to the streambed exists about 0.25 miles upstream of the project site. Construction access from this point requires traversing about a quarter mile of the streambed upstream of the project site and disturbing existing vegetation within the streambed. During earlier design phases, the resource agencies considered the disturbance to the streambed and vegetation to be too great to consider access from Creek Drive as a viable option. As noted above, the project will restore the access route to pre‐project conditions. NHC anticipates that the project will be constructed between June and mid‐October when San Francisquito Creek is not conveying water and the streambed is dry and groundwater levels are relatively deep below the streambed. Rainfall events are relatively rare during this time of year and generally do not produce significant flow. Based on the historic conditions, NHC believes construction will not include dewatering and fish rescue and relocation. Excavation within the streambed will be relatively shallow and is unlikely to intercept groundwater, which will limit the need to control water. Dam removal will involve demolishing the existing dam while protecting the existing concrete slope protection and removing and disposing of debris from the project site. Construction equipment will likely include a small excavator with a hydraulic breaker attachment to demolish the dam and excavator to load trucks. Debris will be disposed at a landfill or other approved site. Preliminary material estimates indicate that about 400 cubic yards of material will excavated from the site and about 180 cubic yards of the excavated sand and gravel will be stockpiled and mixed with imported engineered streambed material to construct the roughened channel. About 600 cubic yards of material will be imported. Construction will likely occur over a period of about 6 weeks and will be scheduled to end prior to October 15th. 9.0 REFERENCES California Department of Fish and Game. 1998. California Salmonid Stream Habitat Restoration Manual. http://www.dfg.ca.gov/nafwb/manual.html Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 16 CalTrans. Standard Specifications, State of California Business, Transportation and Housing Agency Department of Transportation. May 2006. http://www.dot.ca.gov/hq/esc/oe/conststand.html. 543 pp. FEMA. 1999. Flood Insurance Study, City of Menlo Park, California, San Mateo County. Community Number 060321. Revised April 21, 1999. http://msc.fema.gov. FEMA. 2003. Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix C: Guidance for Riverine Flooding Analyses and Mapping. April 2003. www.fema.gov/fhm/dl_cgs.shtm. Interagency Advisory Committee on Water Data. 1982. Guidelines for determining flood flow frequency: Bulletin 17B of the Hydrology Subcommittee, Office of Water Data Coordination, U.S. Geological Survey, Reston, VA. Transport Association of Canada. 2004. Guide to Bridge Hydraulics, 2nd Edition. Thomas Telford. 70 pp. USACE 1991. Hydraulic Design of Flood Control channels. Engineering and Design Manual. Engineering and Design Manual EM‐1110‐2‐1601, U.S. Army Corps of Engineers, Washington DC. USACE. 2010. HEC‐RAS River Analysis System. Version 3.1.3. January 2010. Developed by the USACE Hydrologic Engineering Center. www.hec.usace.army.mil. Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX A: HYDROLOGY APPENDIX A: HYDROLOGY Contents: • PeakFQ Flow Frequency Output • Flow Frequency Plot • Flow Duration Plot 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.000.000 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 --- PROCESSING OPTIONS --- Plot option = Graphics & Printer Basin char output = None Print option = Yes Debug print = No Input peaks listing = Long Input peaks format = WATSTORE peak file Input files used: peaks (ascii) - P:\50454\HYDROLOGY\FLOWFREQ\PKS06WS.TXT specifications -PKFQWPSF.TMP Output file(s): main - P:\50454\HYDROLOGY\FLOWFREQ\PKS06WS.PRT 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.001.001 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 Station - 11164500 SAN FRANCISQUITO C A STANFORD UNIVERSITY CA I N P U T D A T A S U M M A R Y Number of peaks in record = 67 Peaks not used in analysis = 0 Systematic peaks in analysis = 67 Historic peaks in analysis = 0 Years of historic record = 0 Generalized skew = -0.300 Standard error = 0.550 Mean Square error = 0.303 Skew option = WEIGHTED Gage base discharge = 0.0 User supplied high outlier threshold = -- User supplied low outlier criterion = -- Plotting position parameter = 0.00 ********* NOTICE -- Preliminary machine computations. ********* ********* User responsible for assessment and interpretation. ********* WCF133I-SYSTEMATIC PEAKS BELOW GAGE BASE WERE NOTED. 1 0.0 WCF198I-LOW OUTLIERS BELOW FLOOD BASE WERE DROPPED. 1 49.9 WCF163I-NO HIGH OUTLIERS OR HISTORIC PEAKS EXCEEDED HHBASE. 24700.8 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.001.002 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 Station - 11164500 SAN FRANCISQUITO C A STANFORD UNIVERSITY CA ANNUAL FREQUENCY CURVE PARAMETERS -- LOG-PEARSON TYPE III FLOOD BASE LOGARITHMIC ---------------------- ------------------------------- EXCEEDANCE STANDARD DISCHARGE PROBABILITY MEAN DEVIATION SKEW ------------------------------------------------------- SYSTEMATIC RECORD 0.0 0.9851 3.1164 0.5084 -1.652 BULL.17B ESTIMATE 49.9 0.9701 3.1386 0.4490 -0.797 ANNUAL FREQUENCY CURVE -- DISCHARGES AT SELECTED EXCEEDANCE PROBABILITIES ANNUAL 'EXPECTED 95-PCT CONFIDENCE LIMITS EXCEEDANCE BULL.17B SYSTEMATIC PROBABILITY' FOR BULL. 17B ESTIMATES PROBABILITY ESTIMATE RECORD ESTIMATE LOWER UPPER 0.9500 205.6 130.6 194.8 139.5 279.9 0.9000 345.6 276.7 334.9 250.9 449.3 0.8000 614.1 598.7 605.3 474.6 768.3 0.6667 997.7 1082.0 992.5 799.2 1229.0 0.5000 1576.0 1776.0 1576.0 1280.0 1952.0 0.4292 1877.0 2106.0 1880.0 1524.0 2341.0 0.2000 3334.0 3386.0 3365.0 2654.0 4347.0 0.1000 4595.0 4125.0 4666.0 3582.0 6199.0 0.0400 6157.0 4708.0 6302.0 4691.0 8606.0 0.0200 7253.0 4965.0 7466.0 5447.0 10350.0 0.0100 8272.0 5125.0 8559.0 6138.0 12020.0 0.0050 9215.0 5226.0 9579.0 6768.0 13590.0 0.0020 10350.0 5304.0 10810.0 7515.0 15500.0 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.001.003 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 Station - 11164500 SAN FRANCISQUITO C A STANFORD UNIVERSITY CA I N P U T D A T A L I S T I N G WATER YEAR DISCHARGE CODES WATER YEAR DISCHARGE CODES 1931 0.0 1974 3410.0 1932 1160.0 1975 2190.0 1933 730.0 1976 82.0 1934 670.0 1977 82.0 1935 1560.0 1978 2470.0 1936 1660.0 1979 1330.0 1937 2620.0 1980 3300.0 1938 1330.0 1981 626.0 1939 120.0 1982 5220.0 1940 3100.0 1983 3420.0 1941 2410.0 1984 1700.0 1951 3650.0 1985 2270.0 1952 2320.0 1986 3480.0 1953 1950.0 1987 1540.0 1954 332.0 1988 712.0 1955 797.0 1989 394.0 1956 5560.0 1990 460.0 1957 125.0 1991 626.0 1958 4460.0 1992 2580.0 1959 868.0 1993 3010.0 1960 1020.0 1994 824.0 1961 12.0 1995 3320.0 1962 996.0 1996 1520.0 1963 3270.0 1997 3250.0 1964 948.0 1998 7200.0 1965 1120.0 1999 2640.0 1966 880.0 2000 3930.0 1967 4000.0 2001 621.0 1968 1130.0 2002 1060.0 1969 2300.0 2003 3730.0 1970 3110.0 2004 1980.0 1971 1000.0 2005 940.0 1972 700.0 2006 4840.0 1973 3390.0 Explanation of peak discharge qualification codes PEAKFQ NWIS CODE CODE DEFINITION D 3 Dam failure, non-recurrent flow anomaly G 8 Discharge greater than stated value X 3+8 Both of the above L 4 Discharge less than stated value K 6 OR C Known effect of regulation or urbanization H 7 Historic peak - Minus-flagged discharge -- Not used in computation -8888.0 -- No discharge value given - Minus-flagged water year -- Historic peak used in computation 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.001.004 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 Station - 11164500 SAN FRANCISQUITO C A STANFORD UNIVERSITY CA EMPIRICAL FREQUENCY CURVES -- WEIBULL PLOTTING POSITIONS WATER RANKED SYSTEMATIC BULL.17B YEAR DISCHARGE RECORD ESTIMATE 1998 7200.0 0.0147 0.0147 1956 5560.0 0.0294 0.0294 1982 5220.0 0.0441 0.0441 2006 4840.0 0.0588 0.0588 1958 4460.0 0.0735 0.0735 1967 4000.0 0.0882 0.0882 2000 3930.0 0.1029 0.1029 2003 3730.0 0.1176 0.1176 1951 3650.0 0.1324 0.1324 1986 3480.0 0.1471 0.1471 1983 3420.0 0.1618 0.1618 1974 3410.0 0.1765 0.1765 1973 3390.0 0.1912 0.1912 1995 3320.0 0.2059 0.2059 1980 3300.0 0.2206 0.2206 1963 3270.0 0.2353 0.2353 1997 3250.0 0.2500 0.2500 1970 3110.0 0.2647 0.2647 1940 3100.0 0.2794 0.2794 1993 3010.0 0.2941 0.2941 1999 2640.0 0.3088 0.3088 1937 2620.0 0.3235 0.3235 1992 2580.0 0.3382 0.3382 1978 2470.0 0.3529 0.3529 1941 2410.0 0.3676 0.3676 1952 2320.0 0.3824 0.3824 1969 2300.0 0.3971 0.3971 1985 2270.0 0.4118 0.4118 1975 2190.0 0.4265 0.4265 2004 1980.0 0.4412 0.4412 1953 1950.0 0.4559 0.4559 1984 1700.0 0.4706 0.4706 1936 1660.0 0.4853 0.4853 1935 1560.0 0.5000 0.5000 1987 1540.0 0.5147 0.5147 1996 1520.0 0.5294 0.5294 1938 1330.0 0.5441 0.5441 1979 1330.0 0.5588 0.5588 1932 1160.0 0.5735 0.5735 1968 1130.0 0.5882 0.5882 1965 1120.0 0.6029 0.6029 2002 1060.0 0.6176 0.6176 1960 1020.0 0.6324 0.6324 1971 1000.0 0.6471 0.6471 1962 996.0 0.6618 0.6618 1964 948.0 0.6765 0.6765 2005 940.0 0.6912 0.6912 1966 880.0 0.7059 0.7059 1959 868.0 0.7206 0.7206 1994 824.0 0.7353 0.7353 1955 797.0 0.7500 0.7500 1933 730.0 0.7647 0.7647 1988 712.0 0.7794 0.7794 1972 700.0 0.7941 0.7941 1934 670.0 0.8088 0.8088 1981 626.0 0.8235 0.8235 1991 626.0 0.8382 0.8382 2001 621.0 0.8529 0.8529 1990 460.0 0.8676 0.8676 1989 394.0 0.8824 0.8824 1954 332.0 0.8971 0.8971 1957 125.0 0.9118 0.9118 1939 120.0 0.9265 0.9265 1976 82.0 0.9412 0.9412 1977 82.0 0.9559 0.9559 1961 12.0 0.9706 0.9706 1931 0.0 -- -- 1 Program PeakFq U. S. GEOLOGICAL SURVEY Seq.001.005 Ver. 5.0 Beta 8 Annual peak flow frequency analysis Run Date / Time 05/06/2005 following Bulletin 17-B Guidelines 07/02/2007 17:04 End PEAKFQ analysis. Stations processed : 1 Number of errors : 0 Stations skipped : 0 Station years : 67 Data records may have been ignored for the stations listed below. (Card type must be Y, Z, N, H, I, 2, 3, 4, or *.) (2, 4, and * records are ignored.) For the station below, the following records were ignored: FINISHED PROCESSING STATION: 11164500 USGS SAN FRANCISQUITO C A STANFORD For the station below, the following records were ignored: FINISHED PROCESSING STATION: 0.1 1 10 100 1000 10000 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00 Percent of Time Exceeded Flo w ( c f s ) San Francisquito Creek at Stanford University Flow Duration Curve for the period between 10/1/1963 to 10/9/1998 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX B: HEC‐RAS MODEL RESULTS A B C D E F G H I J K L M N O P 1 A B C D E F G H I J K L M N O P 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 nhc SAN FRANCISQUITO CREEK Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX B: HYDRAULIC MODEL RESULTS 0 50 100 150 20042 44 46 48 50 52 54 56 58 60 Main Channel Distance (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Project-rev WS 100-Year - Exist-rev WS 25-Year - Project-rev WS 25-Year - Exist-rev WS 10-Year - Project-rev WS 10-Year - Exist-rev Crit 100-Year - Project-rev Crit 100-Year - Exist-rev Crit 25-Year - Project-rev Crit 25-Year - Exist-rev Crit 10-Year - Project-rev Crit 10-Year - Exist-rev Ground Ground 200 213 250 260 270 279 285 300 333 BONDE CENTERLINE BONDE CENTERLINE 10 20 30 40 50 60 70 8040 45 50 55 60 65 70 RS = 333 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev Crit 100-Year - Exist-rev WS 100-Year - Project-rev Crit 100-Year - Project-rev WS 25-Year - Exist-rev Crit 25-Year - Exist-rev WS 25-Year - Project-rev Crit 25-Year - Project-rev WS 10-Year - Project-rev Crit 10-Year - Project-rev WS 10-Year - Exist-rev Crit 10-Year - Exist-rev Ground - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 0 50 100 150 20040 45 50 55 60 65 70 75 RS = 300 Station (ft) Ele v a t i o n ( f t ) Legend Crit 100-Year - Project-rev Crit 100-Year - Exist-rev Crit 25-Year - Project-rev WS 100-Year - Project-rev Crit 25-Year - Exist-rev Crit 10-Year - Project-rev WS 100-Year - Exist-rev WS 25-Year - Project-rev Crit 10-Year - Exist-rev WS 25-Year - Exist-rev WS 10-Year - Project-rev WS 10-Year - Exist-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev 0 50 100 150 20045 50 55 60 65 70 75 RS = 285 Station (ft) Ele v a t i o n ( f t ) Legend WS 25-Year - Exist-rev Crit 100-Year - Project-rev Crit 100-Year - Exist-rev WS 10-Year - Exist-rev Crit 25-Year - Project-rev Crit 25-Year - Exist-rev WS 10-Year - Project-rev WS 100-Year - Project-rev WS 100-Year - Exist-rev Crit 10-Year - Project-rev Crit 10-Year - Exist-rev WS 25-Year - Project-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 0 20 40 60 80 10045 50 55 60 65 70 75 RS = 279 Station (ft) Ele v a t i o n ( f t ) Legend Crit 100-Year - Exist-rev Crit 100-Year - Project-rev WS 100-Year - Exist-rev Crit 25-Year - Exist-rev WS 25-Year - Exist-rev Crit 25-Year - Project-rev WS 10-Year - Project-rev WS 100-Year - Project-rev Crit 10-Year - Exist-rev WS 10-Year - Exist-rev WS 25-Year - Project-rev Ground - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Bank Sta - Project-rev 0 50 100 150 20040 45 50 55 60 65 70 75 RS = 270 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 25-Year - Exist-rev Crit 100-Year - Project-rev WS 10-Year - Exist-rev WS 10-Year - Project-rev Crit 25-Year - Project-rev Crit 100-Year - Exist-rev WS 100-Year - Project-rev Crit 10-Year - Project-rev WS 25-Year - Project-rev Crit 25-Year - Exist-rev Crit 10-Year - Exist-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 0 20 40 60 80 10040 45 50 55 60 65 70 75 RS = 260 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 25-Year - Exist-rev WS 25-Year - Project-rev Crit 100-Year - Project-rev WS 10-Year - Exist-rev WS 10-Year - Project-rev Crit 25-Year - Project-rev WS 100-Year - Project-rev Ground - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Bank Sta - Project-rev 0 50 100 150 20040 45 50 55 60 65 70 75 RS = 250 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 100-Year - Project-rev WS 25-Year - Exist-rev WS 25-Year - Project-rev Crit 100-Year - Project-rev WS 10-Year - Exist-rev WS 10-Year - Project-rev Crit 100-Year - Exist-rev Crit 25-Year - Project-rev Crit 25-Year - Exist-rev Crit 10-Year - Project-rev Crit 10-Year - Exist-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 0 20 40 60 80 10040 45 50 55 60 65 70 75 RS = 213 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Project-rev WS 100-Year - Exist-rev WS 25-Year - Exist-rev WS 25-Year - Project-rev WS 10-Year - Exist-rev WS 10-Year - Project-rev Ground - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Bank Sta - Project-rev 0 50 100 150 20040 45 50 55 60 65 70 75 RS = 200 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 100-Year - Project-rev WS 25-Year - Project-rev WS 25-Year - Exist-rev Crit 100-Year - Exist-rev Crit 100-Year - Project-rev WS 10-Year - Project-rev WS 10-Year - Exist-rev Crit 25-Year - Exist-rev Crit 25-Year - Project-rev Crit 10-Year - Exist-rev Crit 10-Year - Project-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report 0 50 100 150 20040 45 50 55 60 65 70 75 RS = 150 Station (ft) Ele v a t i o n ( f t ) Legend WS 100-Year - Exist-rev WS 100-Year - Project-rev WS 25-Year - Exist-rev WS 25-Year - Project-rev WS 10-Year - Exist-rev WS 10-Year - Project-rev Crit 100-Year - Exist-rev Crit 100-Year - Project-rev Crit 25-Year - Exist-rev Crit 25-Year - Project-rev Crit 10-Year - Exist-rev Crit 10-Year - Project-rev Ground - Exist-rev Ineff - Exist-rev Bank Sta - Exist-rev Ground - Project-rev Ineff - Project-rev Bank Sta - Project-rev Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report Reach River Sta Profile Plan Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) BONDE CENTERLINE 333 100‐ Year Project‐ rev 8272.00 44.00 59.17 59.17 64.63 0.010354 18.92 458.01 44.35 0.97 BONDE CENTERLINE 333 100‐ Year Exist‐ rev 8272.00 44.00 59.23 59.23 65.09 0.008584 19.74 460.64 44.46 0.95 BONDE CENTERLINE 333 25‐Year Project‐ rev 6157.00 44.00 56.84 56.84 61.62 0.011018 17.63 359.44 40.21 0.98 BONDE CENTERLINE 333 25‐Year Exist‐ rev 6157.00 44.00 56.88 56.88 61.90 0.009391 18.14 361.07 40.28 0.97 BONDE CENTERLINE 333 10‐Year Project‐ rev 4595.00 44.00 54.96 54.96 59.04 0.011481 16.25 286.90 36.86 0.99 BONDE CENTERLINE 333 10‐Year Exist‐ rev 4595.00 44.00 54.94 54.94 59.20 0.010264 16.64 285.99 36.82 0.98 BONDE CENTERLINE 300 100‐ Year Project‐ rev 8272.00 43.61 55.04 57.54 63.79 0.025268 23.74 348.48 42.66 1.46 BONDE CENTERLINE 300 100‐ Year Exist‐ rev 8272.00 43.61 53.74 56.97 64.14 0.031182 25.88 319.63 40.78 1.63 BONDE CENTERLINE 300 25‐Year Project‐ rev 6157.00 43.61 53.44 55.57 60.83 0.025456 21.81 282.27 40.36 1.45 BONDE CENTERLINE 300 25‐Year Exist‐ rev 6157.00 43.61 52.21 54.92 61.00 0.031413 23.79 258.76 38.58 1.62 BONDE CENTERLINE 300 10‐Year Project‐ rev 4595.00 43.61 52.12 53.87 58.30 0.025433 19.95 230.37 38.46 1.44 BONDE CENTERLINE 300 10‐Year Exist‐ rev 4595.00 43.61 50.92 53.18 58.33 0.031648 21.85 210.33 36.67 1.61 BONDE CENTERLINE 285 100‐ Year Project‐ rev 8272.00 45.00 54.66 57.17 63.20 0.048942 23.51 356.68 52.39 1.53 BONDE CENTERLINE 285 100‐ Year Exist‐ rev 8272.00 45.42 54.31 56.96 63.29 0.026359 24.07 347.82 51.84 1.58 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report BONDE CENTERLINE 285 25‐Year Project‐ rev 6157.00 45.00 53.71 55.42 60.02 0.043432 20.17 307.41 50.86 1.41 BONDE CENTERLINE 285 25‐Year Exist‐ rev 6157.00 45.42 57.25 55.20 59.69 0.004565 12.59 506.96 56.47 0.70 BONDE CENTERLINE 285 10‐Year Project‐ rev 4595.00 45.00 54.96 53.97 57.39 0.013200 12.53 372.30 52.87 0.80 BONDE CENTERLINE 285 10‐Year Exist‐ rev 4595.00 45.42 55.67 53.77 57.61 0.004528 11.20 419.73 53.98 0.68 BONDE CENTERLINE 279 100‐ Year Project‐ rev 8272.00 45.00 54.45 56.89 62.87 0.047661 23.41 362.16 55.01 1.52 BONDE CENTERLINE 279 100‐ Year Exist‐ rev 8272.00 46.08 55.70 57.38 62.58 0.008536 21.18 409.94 57.33 1.31 BONDE CENTERLINE 279 25‐Year Project‐ rev 6157.00 45.00 53.53 55.24 59.72 0.041794 20.04 312.27 53.02 1.39 BONDE CENTERLINE 279 25‐Year Exist‐ rev 6157.00 46.08 55.63 55.63 59.51 0.004862 15.90 406.16 57.25 0.99 BONDE CENTERLINE 279 10‐Year Project‐ rev 4595.00 45.00 55.05 57.24 0.011233 11.97 395.45 56.33 0.75 BONDE CENTERLINE 279 10‐Year Exist‐ rev 4595.00 46.08 54.23 54.23 57.45 0.005184 14.45 327.59 54.56 0.99 BONDE CENTERLINE 270 100‐ Year Project‐ rev 8272.00 45.00 53.69 56.31 62.38 0.058426 23.73 354.06 60.55 1.68 BONDE CENTERLINE 270 100‐ Year Exist‐ rev 8272.00 42.73 58.87 54.39 60.72 0.001230 10.96 794.01 66.93 0.53 BONDE CENTERLINE 270 25‐Year Project‐ rev 6157.00 45.00 52.89 54.74 59.29 0.051643 20.34 306.02 59.77 1.55 BONDE CENTERLINE 270 25‐Year Exist‐ rev 6157.00 42.73 57.12 52.80 58.49 0.001099 9.43 678.27 65.24 0.49 BONDE CENTERLINE 270 10‐Year Project‐ rev 4595.00 45.00 55.35 53.46 56.99 0.008030 10.32 457.40 63.38 0.65 BONDE 270 10‐Year Exist‐4595.00 42.73 55.60 51.52 56.62 0.000984 8.12 580.67 63.68 0.45 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report CENTERLINE rev BONDE CENTERLINE 260 100‐ Year Project‐ rev 8272.00 45.00 53.58 55.98 61.63 0.053290 22.82 367.13 62.05 1.60 BONDE CENTERLINE 260 100‐ Year Exist‐ rev 8272.00 42.48 58.96 60.65 0.002095 10.53 831.17 72.48 0.51 BONDE CENTERLINE 260 25‐Year Project‐ rev 6157.00 45.00 56.88 54.42 58.71 0.007032 10.97 582.47 68.44 0.62 BONDE CENTERLINE 260 25‐Year Exist‐ rev 6157.00 42.48 57.17 58.44 0.001893 9.10 704.50 69.07 0.47 BONDE CENTERLINE 260 10‐Year Project‐ rev 4595.00 45.00 55.40 56.86 0.006945 9.75 483.48 65.58 0.60 BONDE CENTERLINE 260 10‐Year Exist‐ rev 4595.00 42.48 55.64 56.59 0.001702 7.86 600.86 66.04 0.43 BONDE CENTERLINE 250 100‐ Year Project‐ rev 8272.00 45.00 58.62 55.81 60.79 0.007231 11.87 711.17 71.79 0.63 BONDE CENTERLINE 250 100‐ Year Exist‐ rev 8272.00 43.14 58.87 54.75 60.62 0.002500 10.67 793.59 72.21 0.54 BONDE CENTERLINE 250 25‐Year Project‐ rev 6157.00 45.00 56.88 54.32 58.61 0.007195 10.56 589.24 68.43 0.61 BONDE CENTERLINE 250 25‐Year Exist‐ rev 6157.00 43.14 57.06 53.17 58.41 0.002374 9.34 666.32 68.89 0.51 BONDE CENTERLINE 250 10‐Year Project‐ rev 4595.00 45.00 55.39 53.02 56.77 0.007263 9.43 488.91 65.69 0.60 BONDE CENTERLINE 250 10‐Year Exist‐ rev 4595.00 43.14 55.52 51.80 56.56 0.002260 8.20 562.44 65.93 0.48 BONDE CENTERLINE 213 100‐ Year Project‐ rev 8272.00 44.00 57.90 60.46 0.008720 12.96 663.08 72.28 0.70 BONDE CENTERLINE 213 100‐ Year Exist‐ rev 8272.00 43.76 57.90 60.43 0.004132 12.85 672.42 72.27 0.69 BONDE 213 25‐Year Project‐6157.00 44.00 56.22 58.28 0.008750 11.57 544.92 68.34 0.68 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report CENTERLINE rev BONDE CENTERLINE 213 25‐Year Exist‐ rev 6157.00 43.76 56.24 58.24 0.004048 11.38 555.77 68.38 0.66 BONDE CENTERLINE 213 10‐Year Project‐ rev 4595.00 44.00 54.78 56.44 0.008872 10.37 448.85 64.84 0.67 BONDE CENTERLINE 213 10‐Year Exist‐ rev 4595.00 43.76 54.81 56.40 0.004004 10.11 460.77 64.93 0.64 BONDE CENTERLINE 200 100‐ Year Project‐ rev 8272.00 43.61 57.89 55.69 60.36 0.003685 13.27 739.41 81.30 0.67 BONDE CENTERLINE 200 100‐ Year Exist‐ rev 8272.00 43.61 57.89 55.69 60.36 0.003685 13.27 739.41 81.30 0.67 BONDE CENTERLINE 200 25‐Year Project‐ rev 6157.00 43.61 56.21 54.08 58.19 0.003532 11.76 606.02 77.06 0.64 BONDE CENTERLINE 200 25‐Year Exist‐ rev 6157.00 43.61 56.20 54.08 58.19 0.003535 11.76 605.84 77.05 0.64 BONDE CENTERLINE 200 10‐Year Project‐ rev 4595.00 43.61 54.76 52.59 56.35 0.003383 10.42 497.40 73.30 0.61 BONDE CENTERLINE 200 10‐Year Exist‐ rev 4595.00 43.61 54.76 52.59 56.35 0.003385 10.43 497.30 73.30 0.61 BONDE CENTERLINE 150 100‐ Year Project‐ rev 8272.00 43.66 58.49 54.36 59.91 0.002001 9.77 931.83 97.49 0.50 BONDE CENTERLINE 150 100‐ Year Exist‐ rev 8272.00 43.66 58.49 54.36 59.91 0.002001 9.77 931.83 97.49 0.50 BONDE CENTERLINE 150 25‐Year Project‐ rev 6157.00 43.66 56.65 52.88 57.81 0.002000 8.74 757.46 92.39 0.48 BONDE CENTERLINE 150 25‐Year Exist‐ rev 6157.00 43.66 56.65 52.88 57.81 0.002000 8.74 757.46 92.39 0.48 BONDE CENTERLINE 150 10‐Year Project‐ rev 4595.00 43.66 55.09 51.73 56.03 0.002003 7.83 615.99 87.03 0.47 BONDE CENTERLINE 150 10‐Year Exist‐ rev 4595.00 43.66 55.09 51.73 56.03 0.002003 7.83 615.99 87.03 0.47 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report Reach River Sta Profile Plan Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl (cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) BONDE CENTERLINE 333 100‐ Year Project‐ rev 8272.00 44.00 59.17 59.17 64.63 0.010354 18.92 458.01 44.35 0.97 BONDE CENTERLINE 333 100‐ Year Exist‐ rev 8272.00 44.00 59.23 59.23 65.09 0.008584 19.74 460.64 44.46 0.95 BONDE CENTERLINE 333 25‐Year Project‐ rev 6157.00 44.00 56.84 56.84 61.62 0.011018 17.63 359.44 40.21 0.98 BONDE CENTERLINE 333 25‐Year Exist‐ rev 6157.00 44.00 56.88 56.88 61.90 0.009391 18.14 361.07 40.28 0.97 BONDE CENTERLINE 333 10‐Year Project‐ rev 4595.00 44.00 54.96 54.96 59.04 0.011481 16.25 286.90 36.86 0.99 Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX C: ROCK SIZING CALCULATIONS Bonde Weir Fish Passage Project Rock Scour Protection Analysis Date: 7/5/2012 By: jh, bw PERCENT OF MIX ROCK SIZE, ft min max 16% 2.5 4.0 34% 1.0 2.5 34% 0.06 1.0 9% 0.01 0.06 7% SAND/SILT Hydraulic Characteristics qf = 165.4 ft3/s/ft Unit discharge in Main Channel Q100 = 8270 ft3/s 1pct AEP (100‐year peak flow) W = 50 ft Main channel width So = 0.01 ft/ft Channel slope = 0.01 ft/ft, USACE (1991) Channel Bed Rock Sizing So = 0.01 ft/ft Channel slope q*1 = 165.4 ft3/s/ft Unit discharge g = 32.2 ft/s2 gravitational acceleration sf = 1 factor of safety D30 = 1.66 ft Abt and Johnson (1990) So = 0.01 ft/ft channel slope q = 165.4 ft2/s design unit discharge fq sizing factor 1.35 ‐ sizing factor qsizing = 223 ft2/s unit discharge for sizing φe = 1.2 ‐ coefficient for the empirical envelope on the regression φc = 1.2 ‐ coefficient for flow concentration assuming sheet flow a = 1 - Shape factor D30 = 1.43 ft D50 = 1.79 ft Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report USACE (1991) Channel Bed Rock Sizing So = 0.01 ft/ft q = 165.4 ft2/s g = 32.2 lbm*ft/s2 nsed= 0.40 - D30-CORPS = 1.66 ft DFG Engineered Bed Material Size D8-ESM = 0.010 ft D16-ESM = 0.06 ft D50-ESM = 1.0 ft D84-ESM = 2.5 ft D100-ESM (calc) = 6.24 ft Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX D: 30% DESIGN DRAWINGS Northwest Hydraulic Consultants Bonde Weir Fish Passage Basis of Design Report APPENDIX D: 30% DESIGN DRAWINGS May 10, 2013 State Coastal Conservancy Doug Bosco, Chair Attn: Amy Hutzel 1330 Broadway, Suite 1300 Oakland, CA 94612-‐2530 Dear Mr. Bosco, I am writing to offer my support for the application of the San Mateo County Resource Conservation District to the California State Coastal Conservancy to complete the Bonde Weir Passage Project on San Francisquito Creek. This project will improve passage for threatened steelhead trout and contribute to the overall restoration of San Francisquito Creek. Acterra works with local agencies and other partners to steward several creekside habitat areas on San Francisquito Creek. We bring hundreds of volunteers each year to remove invasive non-‐native plants and install locally native plants grown at our native plant nursery. Volunteers learn about local ecology and actions they can take to improve watershed health. One of our longstanding restoration sites is El Palo Alto Park, which is adjacent to the Bonde Weir project. This year alone we have held 5 volunteer days at this site and hosted a Coastal Cleanup Day event on this reach of creek. We are pleased to work with the San Mateo County Resource Conservation District to see this project accomplished with funding from the California State Coastal Conservancy. During construction, Acterra will recruit and organize volunteers to assist in revegetation and maintenance efforts, using plants supplied by our nursery, which has growing plants local to the San Francisquito Watershed for over 15 years. Since the project is in a residential area and equipment must be staged inside a popular park, we expect this will be a great opportunity to increase the community’s understanding about San Francisquito Creek and efforts to support the steelhead who depend on the creek for their survival. Additionally, we plan to continue our ongoing stewardship work at El Palo Alto Park in future years, and can therefore serve as “eyes on the creek” for this project site as it evolves. Please contact me if I can provide any other information about my organization and our support for the Bonde Weir fish passage project. I can be reached at junkob@acterra.org or 650-‐962-‐9876 x347. Sincerely, Junko Bryant Watershed Program Coordinator Acterra Action for a Healthy Planet 3921 East Bayshore Road Palo Alto ca 94303-4303 tel 650.962.9876 fax 650.962.8234 www.Acterra.org info@Acterra.org 650-324-1972 * jpa@sfcjpa.org * 615 B Menlo Avenue * Menlo Park, CA 94025 sfcjpa.org East Palo Alto, Menlo Park, Palo Alto, San Mateo County Flood Control District, and the Santa Clara Valley Water District May 7, 2013 California State Coastal Conservancy Doug Bosco, Chair 1330 Broadway, Suite 1300 Oakland, CA 94612-2530 SUBJECT: San Mateo County Resource Conservation District application for grant funding to construct the Bonde Weir Fish Passage Improvement Project Dear Mr. Bosco, I am writing to express support of the San Mateo County Resource Conservation District’s application to the State Coastal Conservancy for construction funding for the Bonde Weir Fish Passage Improvement Project. The San Francisquito Creek Joint Powers Authority (SFCJPA) is a regional government agency established to plan and implement projects that enhance flood protection, ecosystem restoration, and recreation within the San Francisquito Creek watershed and floodplain. Member Agencies of the SFCJPA include the cities of East Palo Alto, Menlo Park and Palo Alto, the San Mateo County Flood Control District, and the Santa Clara Valley Water District. The Bonde Weir represents the largest and most significant barrier to steelhead migration on main- stem San Francisquito Creek. The SFCJPA is pleased to have begun working with a new partner, the San Mateo County Resource Conservation District, which has taken the lead on implementation of this important project. The project, when completed, will provide for improved passage for both in-migrating adult and out-migrating smolt steelhead in a watershed identified as key to the regional restoration efforts for the Central California Coast Evolutionary Significant Unit of the species. The project is complimentary to the efforts of the SFCJPA, its member agencies, and the comprehensive restoration vision of the communities it serves. Please contact me directly at kmurray@sfcjpa.org or 650.324.1972 if you would like more information on the SFCJPA’s activities or our support of the proposed project. Sincerely, Kevin Murray Project Manager