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HomeMy WebLinkAboutResolution 2019-003 N.C.S. 01/07/2019Resolution No. 2019-003 N.C.S. of the City of Petaluma, California RESOLUTION ADOPTING A MITIGATED NEGATIVE DECLARATION FOR THE DENMAN REACH PHASE 4 PROJECT AND APPROVE THE PROJECT WITH THE INCORPORATION OF MITIGATION MEASURES WHEREAS, the City of Petaluma has adopted policies calling for the development of flood terraces and a riverfront trail system in the 1996 River Access and Enhancement Plan and the 2008 General Plan 2025; and WHEREAS, the Sonoma County Water Agency has been awarded an initial grant from the State Department of Water Resources in the amount of $1,754,322 for land acquisition and flood control management in the Denman Reach area of the Petaluma River; and WHEREAS, the Sonoma County Water Agency (Agency) has approved $881,600 in funding for the project; and WHEREAS, the Agency entered into an agreement with the City to provide $2,635,000 in funding to execute a flood protection project to acquire a vacant 5.47 -acre parcel on Industrial Avenue, create a flood detention basin, create additional river front trails, and remove sediment buildup in the Petaluma River at the Corona Road Bridge; and WHEREAS, the City prepared an Initial Study for the Project consistent with CEQA Guidelines sections 15070 through 15074.1 and determined that a Mitigated Negative Declaration (MND) was required to analyze the potential for new or additional significant environmental impacts of the Project beyond those identified in the General Plan EIR; and WHEREAS, on or before August 22, 2018, the City's Notice of Availability and Notice of Intent to Adopt a MND based on the Initial Study, providing for a minimum of 30 -day public comment period commencing August 23, 2018 and ending September 22, 2018 published and mailed to all property owners within 500 feet of the Project as well as all persons having requested special notice of said proceedings; and Resolution No. 2019-003 N.C.S. Page I WHEREAS, pursuant to the analysis in the Initial Study, the Project does not have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, substantially reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory; and WHEREAS, pursuant to further analysis in the Initial Study, the Project does not make significant impacts that are individually limited, but cumulatively considerable, nor have environmental effects which may cause substantial adverse effects on human beings, either directly or indirectly; and WHEREAS, on January 7, 2019, at a duly noticed public meeting, the Petaluma City Council reviewed the MND, all supporting documents including but not limited to the Initial Study and proposed amendments and additions, staff reports and related materials, and all public comments and evidence presented at or before the meeting; and WHEREAS, the Initial Study and MND identify mitigation measures applicable to the Project, as incorporated herein by reference; and WHEREAS, the Project is not located on a site listed on any Hazardous Waste Site List compiled by the State pursuant to Section 65962.5 of the California Government Code; and WHEREAS, the MND reflects the City's independent judgment and analysis of the potential for environmental impacts from the Project; and WHEREAS, the MND, Revised Initial Study, and related project and environmental documents, including the General Plan 2025 EIR and all documents incorporated herein by reference, are available for review in the City Community Development Department at Petaluma City Hall, during normal business hours. The custodian of the documents and other materials which constitute the record of proceedings for the proposed project is the City of Petaluma Public Works and Utilities, 2020 North McDowell Blvd, Petaluma, CA 94954, Attn: Tim Moresco, Associate Civil Engineer. Resolution No. 2019-003 N.C.S. Page 2 NOW, THEREFORE BE IT RESOLVED, that the City Council of the City of Petaluma hereby: 1. Based on its review of the entire record herein, including the MND, the Initial Study, all supporting, referenced and incorporated documents and all comments received and responses and additions thereto, the City Council further finds that there is no substantial evidence that the Project as mitigated and conditioned will have a significant effect on the environment, that the Mitigated Negative Declaration reflects the City's independent judgment and analysis, and that the Mitigated Negative Declaration, Initial Study as amended, and supporting documents provide an adequate description of the impacts of the Project and comply with CEQA, the State CEQA Guidelines and the City of Petaluma Environmental Guidelines. 2. The Initial Study and MND shall incorporate the text additions and amendments contained in the attached Attachment 1 (Attachment 4 to staff report). 3. The City Council adopts the Mitigation and Monitoring and Reporting Program set forth in Exhibit A hereto and incorporated by reference. All mitigation measures contained therein shall be conditions of approval of the Project. 4. The City Council hereby approves the Petaluma River Flood Management Denman Reach Phase 4 Project. Under the power and authority conferred upon this Council by the Charter of said City. REFERENCE: I hereby certify the foregoing Resolution was introduced and adopted by the Council of the City of Petaluma at a Regular meeting on the Th day of January 2019, by the following vote: AYES: Mayor Barrett; Fischer; Vice Mayor Healy; Kearney; King; McDonnell, Miller NOES: None ABSENT: None ABSTAIN: None r' ATTEST: City Clerk to ity Mayor Resolution No. 2019-003 N.C.S. Page 3 EXHIBIT A w`llop. LU City of Petaluma, California R Public Works and Utilities Department IggB Project Name: Denman Reach Phase 4 Address/Location: 1300 block Industrial Ave. (APN 007-412-033) Petaluma River/Corona Bridge REPORTING/MONITORING RECORD — MITIGATION MEASURES This document has been developed pursuant to the California Environmental Quality Act, Public Resource Code Section 21.081.6 to ensure proper and adequate monitoring or reporting in conjunction with project approval which relies upon a Mitigated Negative Declaration, Resolution No. 2019-003 N.C.S. Page 4 Review Due Date Staff Dept. Date Completed Initials Biological Resources A. BI0-1: Prior to filling of jurisdictional waters, PW&U, RPI or construction activities within Corps, CDFW, RWQCB or CDFW jurisdiction, necessary RWQCB regulatory permits will be obtained from the appropriate agencies. Regulatory permits to be obtained include a Corps Permit, Regional Water Quality Control Board Section 401 Water Quality Certification and/or Waste Discharge Requirement. Prior to proposed filling of jurisdictional waters, compliance with all regulatory agency permit conditions shall be demonstrated. Permanent impacts to jurisdictional wetlands will be mitigated 1.5:1 ratio at a minimum, with the 1:1 relating to on- site restoration and 0.5 of additional mitigation to compensate for temporal losses, on a functions and values basis by: (1) restoring wetlands in the Study Area; (2) purchasing an appropriate amount of mitigation credits by an approved mitigation bank, or (3) another type of mitigation as approved by the Corps, RWQCB, and/or CDFW through the permitting process. With the implementation of these measures, the Project impact on waters of the U.S. and State will be less than significant. B. BI0-2: Prior to removing riparian vegetation PW&U, RPI or construction activities within CDFW or CDFW, RWQCB jurisdiction, necessary regulatory RWQCB Resolution No. 2019-003 N.C.S. Page 4 Resolution No. 2019-003 N.C.S. Page 5 Review Due Date Staff Dept. Date Completed Initials permits will be obtained from the appropriate agencies. Regulatory permits to be obtained include a CFGC Section 1602 Streambed Alteration Agreement. The project shall comply with all regulatory agency permit conditions and compensatory mitigation measures as determined and required by regulatory agencies during permit authorization but shall be no less than 1:1 replacement ratio. Mitigation options will include the following: (1) planting replacement riparian vegetation, (2) purchase of mitigation bank credits from an approved mitigation bank, and/or (3) paying an in -lieu fee to a natural resource agency or habitat resource organization. For habitat that is preserved and/or established for mitigation, a Habitat Mitigation and Monitoring Plan (HMMP) shall be prepared. The HMMP will include a detailed description of restoration/enhancement/preservation actions; restoration performance criteria for each biological parameter (i.e., native/invasive plants, wildlife use); and monitoring/maintenance/reporting requirements for each biological parameter to evaluate restoration performance criteria. With the implementation of these measures, the Project impact on riparian vegetation will be less than significant. C. 13I0-3: A permit from the City of Petaluma PW&U, COC will be acquired for the removal of any PD protected tree within City limits. Conditions of approval may include tree replacement plantings or the payment of in -lieu fees. With the implementation of these measures, the Project impact on protected trees will be less than significant. D. BIO -4: Six special -status plant species have PW&U, CA potential to occur in the Study Area. To avoid CCNB, impacts to special -status plants, protocol -level DFG surveys shall be conducted during the documented bloom period of the species. Two site visits, including one early -season (May), and one late -season (July) will be sufficient to cover the bloom periods of the six species with potential to occur. Survey timing may fluctuate based on blooming periods of appropriate reference site locations. Ifspecial- Resolution No. 2019-003 N.C.S. Page 5 Resolution No. 2019-003 N.C.S. Page 6 Review Due Date Staff Dept. Date Completed Initials status plant surveys result in negative findings, no impacts would occur, and no mitigation would be required. However, if special -status plants are identified in the impact area, mitigation will be required. Mitigation will include avoidance, or if avoidance is not feasible, seeds collection and re-establishment at a minimum 1:1 ratio (number of plant established: number of plants impacted) in preserved, suitable habitat. Re-established populations shall be monitored annually in accordance with an approved HMMP for a minimum of five years. Reports describing performance results will be prepared and submitted for years 1, 3, and 5 during the monitoring period. With the implementation of these measures, the Project impact on special -status plants will be less than significant. E. BIO -5: While trees are not typically used as PW&U, CA hibernation roosts, mature oaks and other SCWA, large trees on the property could potentially be CDFW used as day or maternity roosting sites by bats. All bat roosts, including those of non -special - status bats are protected by CDFW. To avoid impacts to roosting bats, any project activities that would impact potential bat roosts shall be initiated outside of the maternity roosting season (March 1 — July 31). If project work such as the felling of trees cannot occur outside of the maternity season, then a bat roost survey shall be conducted within 14 days prior to the start of such activities. Any structures or trees that are determined to support roosts shall have a 200 -foot no work buffer placed around them, and the buffer shall not be lifted until the maternity season has completed. In addition, when any large trees are removed, they shall be allowed to lie undisturbed on the ground for one night to allow any roosting bats to escape on their own before the trees are processed. With the implementation of these measures, the Project impact on bats will be less than significant, F. BIO -6: For the protection of special -status PW&U, CoC birds, and native nesting birds protected by the PD MBTA and CFGC, future Project activities shall occur outside of the nesting season from September 1 —January 31, to the extent Resolution No. 2019-003 N.C.S. Page 6 Resolution No. 2019-003 N.C.S. Page 7 Review Dept. Due Date Date Completed Staff Initials feasible. If working outside of the nesting season is not possible, and project activities are initiated during the nesting season (February 1 — August 31), a qualified wildlife biologist shall conduct a nesting bird survey no more than 14 days prior to the start of Project activities. If no active nests are identified during the surveys, no impacts will occur to birds and work will progress without restriction. If active nests are identified, a no - disturbance buffer around the nest shall be implemented to avoid impacts to nesting birds. Buffers will be determined by a qualified biologist, and typically range from 25 feet to 500 feet depending on the species and protection status of that species. Once an active nest is determined to no longer be active, because of young fledging or predation, the buffer around the nest shall be removed and work shall progress without restriction. With the implementation of these measures, the Project impact on nesting and/or protected birds will be less than significant, G. BIO -7: Aquatic habitat activities shall be PW&U, RPI, completed during the dry season, between CDFW, CA July 15 and October 1. Regulatory approval RWQCB shall be obtained for all work within potentially jurisdictional areas from respective agencies. Approvals from the RWQCB, CDFW, and Corps are required based on project designs (City of Petaluma 2016). The Petaluma River is also designated critical habitat for California central coast chinook and California central coast steelhead and is considered EFH for coho and chinook salmon. Therefore, it is likely that the Corps will consult with the USFWS and NMFS for impacts to the Petaluma River. All work within these areas shall conform to any conditions imposed by the regulating agencies. Prior to construction, the contractor shall be required to prepare an Accidental Spill Prevention and Cleanup Plan. This plan shall include required spill control absorbent material, for use beneath stationary equipment, to be present on-site and available at all times. Resolution No. 2019-003 N.C.S. Page 7 Resolution No, 2019-003 N.C.S, Page 8 Review Due Date Staff Dept. Date Completed Initials All refueling and maintenance of equipment, other than stationary equipment, shall occur at least 100 feet from the creek's top -of -bank. Refueling or maintenance of stationary equipment within the channel (top of bank to top of bank) shall only occur when secondary containment sufficient to eliminate escape of all potential fluids is in place. Any hazardous chemical spills shall be cleaned immediately. All stockpiling of construction materials, equipment, and supplies, including storage of chemicals, refueling and maintenance, with the exception of stationary equipment, shall occur outside the creek channel. No equipment shall be washed where runoff could enter the creek. No motorized equipment shall be left within the channel (top of bank to top of bank) overnight. Work shall be conducted in isolation from flowing water. Prior to the start of construction activities, the work area shall be isolated using temporary water diversion materials such as sand bags or other similar methods, and flowing water shall be temporarily diverted around the isolated area. A 3 to 5 -foot buffer zone will be created, offset from the sandbags, to further reduce the chances of sediment depositing into the river during construction. If de -watering is necessary, pumps with 0.2 - inch mesh shall be used to remove standing water from the work area within the cofferdams to a filtration basin to prevent direct discharge into the creek. If a filtration basin is not available, filter bags will be placed surrounding the hose -release and the hose - release end shall be placed on a level area outside of the wetted creek channel to allow water to settle prior to returning to the creek. No pumped water shall be directly discharged into the creek. Allowing the pumped water to settle in a filtration basin or release through filter bags will prevent increase in turbidity or sediment loads during the de -watering Resolution No, 2019-003 N.C.S, Page 8 Resolution No. 2019-003 N.C.S. Page 9 Review Dept. Due Date Date Completed Staff Initials process. If de -watering is necessary, a de- watering plan shall be submitted for agency approval. By implementing these measures, the Project's impacts to special -status fish, including salmonids, shall be reduced to less than significant. H. BIO -8: Although the lack of upland habitat, PW&U CA lack of connectivity to suitable breeding habitat, intense flooding, sedimentation and introduced predators/competitors reduce the potential for CRLF to occur within the Study Area, measures to avoid CRLF impacts shall be implemented. The following measures shall be implemented to avoid CRLF and are in agreement with the measures described in the NLAA that was issued for this project (Corps 2016). An environmental awareness training for all crews working on the site shall include education on sensitive resources such as protected wildlife with the potential to occur within the area (identification, regulatory status, natural history), water quality and environmental protection measures. Within 48 hours prior to any construction activities, a biologist approved by USFWS (Approved Biologist) shall conduct surveys for CRLF in and adjacent to the Action Area, 100 feet upstream and 100 feet downstream of the Study Area. The Approved Biologist shall have stop work authority to protect natural resources or ensure personal safety or the safety of workers. If CRLF are detected during surveys, work shall cease until consultation with the appropriate agencies can be completed. If no CRLF are found during the preconstruction surveys, the Study Area shall be surveyed each day prior to commencement of work by the Approved Biologist or a qualified biologist under the direction of the Approved Biologist to ensure that no CRLF are present in the Study Area until vegetation Resolution No. 2019-003 N.C.S. Page 9 Resolution No. 2019-003 N.C.S. Page 10 Review Dept. Due Date Date Completed Staff Initials removal and exclusion fence installation are complete. After vegetation clearance and exclusion fence installation, activities may continue inside fenced areas without the presence of a biologist unless work is halted for more than 10 days, then a pre -construction survey for CRLF shall be conducted prior to re-initiation of work. All workers shall ensure that food scraps, paper wrappers, food containers, cans, bottles, and other trash from the work area are deposited in covered or closed trash containers. Trash in the containers shall be removed and disposed of off-site daily. Prior to the commencement of operation of wheeled or equipment with tracks in undisturbed areas, vegetation that could conceal CRLF shall be removed by hand under the supervision of a qualified biologist after the Approved Biologist has surveyed the area and determined it to be free of CRLF. If vegetation is too dense to be adequately surveyed (tall grasses, blackberry etc.), the Approved Biologist, at his or her discretion, may request that vegetation is cut to a height of 6-12 inches (and cut vegetation removed) prior to conducting a survey. If no CRLF are found, the vegetation shall be cut to ground level, and this shall ensure that no CRLF are harmed by cutting tools. Exclusion fence shall be installed around staging areas and Study Areas after vegetation removal is complete. A qualified biologist under direction of the Approved Biologist will oversee the installation of the fence. Once the fence is installed, the periodic inspections by the qualified biologist and construction contractor shall ensure that the fence is maintained effectively for the duration of the project. If exit/entries to the enclosed areas are required, they shall be closed at the end of work each day to ensure exclusion of CRLF overnight. Erosion control structures shall not include plastic or be of types that may entrap wildlife Resolution No. 2019-003 N.C.S. Page 10 Resolution No, 2019-003 N.C.S. Page I l Review Due Date Staff Dept. Date Completed Initials and shall be constructed of tightly woven natural fibers. All construction activities shall cease one half hour before sunset and shall not begin prior to one half hour before sunrise. Additionally, construction activities shall not occur during rain events or within 24 hours of events projected to deliver >0.2 inches of rain or within 24 hours after rain events exceeding 0.2 inches in measurable precipitation, as CRLF are most likely to disperse during periods of precipitation. No work shall occur after 0.5 inches of rain has occurred after November 1 in the year work is occurring. Any open holes or trenches shall be covered or have escape ramps no steeper than 45 degrees installed at the end of each working day to prevent CRLF from becoming entrapped. With the implementation of these measures and those described for special - status fish (13I0-7), any impacts to CRLF shall be avoided. 1. BIO -9: Prior to the initiation of Project work PW&U CoC in the reservoir or banks of the reservoir, a qualified biologist shall conduct a preconstruction survey for pond turtles. If a pond turtle is found during surveys, the qualified biologist will relocate it outside of the Study Area, out of harm's way or it shall be allowed to move out of the area under its own power. With the implementation of these measures and those previously described for CRLF (BIO -7) and aquatic habitats (BIO -1 and BIO -2) (exclusion fence, work windows etc.), the impacts to Pacific pond turtle will be less than significant. and Soils -Geology J. GEO-1: All provisions of the City of Petaluma PW&U, CA Grading Ordinance, the project plans, and the PD project geotechnical report prepared for Phases 1 and 2 will be followed. Finished grades will not be steeper than 211:1 V. K. GEO-2: Earthwork, including grading and fill PW&U, COC, placement will only occur between the period of PD CA June 1 and October 15. All disturbed areas will be stabilized upon final grading and protected using a combination of perinanent vegetative Resolution No, 2019-003 N.C.S. Page I l Resolution No. 2019-003 N.C.S. Page 12 Review Due Date Staff Dept, Date Completed Initials treatment, mulching, geotextiles, as shown in the project Erosion Control Plan (ECP) to be included in the grading plans. In addition, the selected construction Contractor will be required to develop a SWPPP (subject to City approval) and implement the Plan. The City's Project Manager will monitor (and document) to ensure that the ECP and SWPPP and other provisions of the approved improvement plans are being followed. L. GEO-3: Site grubbing and earthmoving PW&U, COC, activities will be completed prior to October 15 DFG CA of the construction year. Work beyond October 15 (except for revegetation until November 15) shall be specifically authorized in advance by the appropriate regulatory agencies. All erosion control shall meet specifications of the City of Petaluma Erosion Control Ordinance. Erosion control and sediment detention devices shall be incorporated into the project design and implemented at the time of construction. These devices shall be in place prior to October 15 and the onset of rains for the purposes of minimizing fine sediment and sediment/water slurry input to flowing water, and of detaining water to retain sediment on-site. These devices will be placed at all locations where the likelihood of sediment input exists. Sediment collected in these devices shall be disposed of away from the collection site and outside riparian areas and flood hazard areas. M. GEO-4: Any soil or rock fill to be installed PW&U, COC, within Water Board jurisdiction will include an RWQCB CA evaluation of biotechnical methods and habitat enhancement features to be incorporated in order to avoid and minimize impacts of hardened structures. All rock must be demonstrated to be necessary and appropriately sized through a hydraulic analysis performed by a qualified professional. If biotechnical methods and habitat enhancement features are demonstrated to be infeasible, mitigation will be required at a 1.5:1 ratio at a minimum. Hydrology and Water Quality N. HYD -1: A detailed Storm Water Pollution PW&U COC, Prevention Plan (SWPPP) shall be prepared and CA implemented by the Contractor, subject to review and approval of the City of Petaluma, as a line item in the construction agreement. Resolution No. 2019-003 N.C.S. Page 12 Resolution No. 2019-003 N.C.S. Page 13 Review Due Date Staff Dept. Date Completed Initials Construction plans should specify all erosion and sediment control measures that will be used, including (where applicable): 1. Limiting access routes to the creek channel and stabilizing access points; 2. Stabilizing graded areas as soon as possible with seeding, mulching, erosion control materials or other effective methods; 3. Delineating clearing limits, easements, setbacks, sensitive areas, vegetation, and drainage courses by marking them in the field; 4. Stabilizing and preventing erosion from temporary conveyance channels and outlets; 5. If rainfall occurs, using sediment controls and filtration to remove sediment from water collected on-site during construction O. HYD -2: Implement established Best PW&U, COC, Management Practices (BMPs) to control short- RWQCB CA term construction water quality impacts. 1. Construction BMPs would reduce erosion of disturbed soils during construction activities and are used to minimize wind and water erosion and transport of sediments during construction. BMPs shall include as a minimum the following measures: 2. Temporary measures, such as flow diversion, temporary ditches, and silt fencing. 3. Surface disturbance of soil and vegetation would be kept to a minimum. 4. Any stockpiled soil, awaiting removal from the site, would be placed, and sloped so that it would not be subject to accelerated erosion. P. HYD -3: Conformance with the State Water RWQCB, RPI, Resources Control Board Construction SCWA, COC, General Permit, including implementation of a PW&U CA Storm Water Pollution Prevention Plan (SWPPP) and the Sonoma County Water Agency (SCWA) Stream Maintenance Program Guidelines, which include Best Management Practices. The BMPs cover selective vegetation management, including use of herbicides and other chemicals. Q. HYD -4: Incorporate potentially hazardous CDFW, RPI, materials storage and handling plan into the PW&U COC, overall Streambed Alteration Agreement. CA Resolution No. 2019-003 N.C.S. Page 13 Department/Aaency Review Due Date Staff PD Planning Division Dept. Date Completed Initials Provisions will include, but not be limited to the SCWA: Sonoma County Water Agency RWQCB: Regional Water Quality following: Control Board 1. Refueling outside the riparian corridor with CA measures for containing accidental fuel RPI Regulatory or Referral Permit spills. Issuance see RA list 2. All construction equipment and machinery shall be checked for leaks prior to entry into the stream channel (note: this BMP would not apply to this project as no rolling equipment is expected to be placed within the stream channel). 3. Any construction equipment shall not be stored or stockpiled in the creek channel. 4. No herbicide application in or near flowing water, and all herbicides shall be applied under the direction of a licensed Pest Control Applicator, and in accordance with appropriate re ulations. Noise R. NOISE -1: Temporary noise impacts will be PW&U COC, limited by restricting construction activities to CA daylight hours: weekdays from 7:00 am to 7:00 pm, and Saturdays 9:00 am to 5:00 pm, with no work on Sundays. This shall exceed standards of the City of Petaluma Noise Ordinance which specifically prohibits construction activity between the hours of 10:00 p.m. and 7:00 a.m. Monday through Friday, and between 10:00 p.m. and 9:00 a.m. on Saturdays, Sundays, and State, Federal, or local holidays. S. NOISE -2: Require hearing protection for PW&U CA workers operating, and in close proximity to, heavy machinery, including chainsaws, brush mowers, and weed trimmers in accordance with CFR 29, Part 1910.95, and OSHA standards. Department/Aaency Recluested By or Due Date PW&U Public Works & Utilities GP Grading Permit PD Planning Division SPAR Site Plan and Architectural Review RA Regulatory/Referral Agency CoC Commencement of Construction SCWA: Sonoma County Water Agency RWQCB: Regional Water Quality Control Board CDFW: Dept, of Fish & Wildlife CA Construction Activit RPI Regulatory or Referral Permit Issuance see RA list Resolution No. 2019-003 N.C.S. Page 14 PCM Post -Construction Monitoring Resolution No. 2019-003 N.C.S. Page 15 Attachment I RESPONSE TO COMMENTS ON DENMAN REACH PHASE 4 PUBLIC DRAFT IS/MND This document provides a response to comments received on the Public Draft Initial Study/Mitigated Negative Declaration (IS/MND) that was prepared for the Denman Reach Phase 4 Project. In accordance with the California Environmental Quality Act (CEQA) of 1970 (as amended) (California Public Resources Code 21000 et. seq.), the Public Draft IS/MND was circulated for a 30 -day public review and comment period from August 27, 2018 to September 26, 2018. Notice of availability and notice of intent to adopt the IS/MND was mailed to property owners within 500 feet of the project site, published in the Argus Courier, posted to the City of Petaluma's (City) Website, and submitted to the State Clearinghouse for distribution to State Agencies. COMMENTS RECEIVED A number of written comments were received during the public review and comment period for the IS/MND. Comments were also received orally from one resident, who neighbors the project area. Agencies, organizations, and individuals that submitted written or oral comments on the IS/MND are listed below; comment letters received on the IS/MND are included in Appendix 1: Agencies 1. California State Clearinghouse 2. California Department of Transportation 3. San Francisco Regional Water Quality Control Board 4. Sonoma County Department of Public Works and Transportation Local Individuals 1. John Aguiar (orally via phone call) SUMMARY OF COMMENTS AND RESPONSES California State Clearinghouse The letter acknowledges that the City of Petaluma complied with the State Clearinghouse review requirements for review of draft environmental documents. The State Clearinghouse also Resolution No. 2019-003 N.C.S. Page 16 forwarded a copy of the comment letter from the California Department of Transportation and San Francisco Regional Water Quality Control Board. No response is necessary. California Department of Transportation (Caltrans) The letter acknowledged project understanding and requested that within the Hydrology and Water Quality section of the MND Checklist, sections d (alter drainage pattern or increase runoff) and e (create or contribute runoff which would exceed the capacity of drainage systems) be addressed in more detail. These sections have been addressed with the following addition to the Discussion section of the Hydrology and Water Quality section: "The removal of the understory vegetation and grading efforts to be done within the river channel around Corona Bridge could cause a temporary increase in runoff potential during construction, and an increase inflow levels downsh eam during a 25 year storm event. During construction, there will be an increase in runoffpotential along the river banks due to the removal of the understofy vegetation, however, this will only be temporary until the new vegetation gets established, which the City will install as part of the project. During a 100 year event the model shows the project will result in a reduction in water surface elevation upstream and downstream of the bridge. For the 25 year event the model shows a slight increase in water surface elevation downstream of Corona Road at the Corona Creek confluence gradually increasing to a maximum increase of 0.09 feet near the constriction weir, and then decreasing again from thatpoint down zero increase near Adobe Creek. There are no structures in the 100 year flood plain near the constriction weir and, thus, no structures would be affected by this 0. 09feet rise in a 25 year event in this area. Other features that will either not impact drainage patterns or will have minimal effect are features such as the detention basins spillways, due to the location at being near the top of the bank, along with the loop tail around the basins. The riprap to be installed along the abutments of the Corona Road Bridge will have minimal impact to the drainage patterns and should not increase runoff, especially considering the bridge will provide cover to prevent runoff from occurring. The goal of this project is to decrease the water surface elevation and flood plain area for the 100 year event by detaining water peak flows within the detention basins, reducing flow constraints, and scour of abutments at the Corona Road bridge. " San Francisco Regional Water Quality Control Board (Water Board) The letter listed how the project described in the Initial Study does not provide a level of clarity needed to appropriately analyze the impacts versus benefits. To provide clarity, the Water Board asked the City to describe, in more detail, the benefits this project will provide to the 100 -year flood map, in terms of infrastructure and buildings. By referring to sheet 1 of 3 in WEST Consultant Inc.'s memo, the green hatch represents the areas of 100 -year flooding that will be removed due to this project. From this diagram, several nearby parcels will see a significant Resolution No. 2019-003 N.C.S. Page 17 amount of flood plain reduction, although none are completely taken out of the 100 -year flood zone. The note also asks the City to provide a figure depicting the increase in flooding that will result from the project during a 25 -year storm. Based on the model results shown in Table 2 of the Memo provided by WEST Consultants, Inc., the largest downstream increase fi-om this project during a 25 -year storm is 0.09 feet, which equates to 1.08 inches near the constriction weir. A graphic depiction of this minor impact wouldn't be relevant as it is within the margin of error introduced in the mapping process. Additionally, there are no structures in the 100 -year flood plain in this area, thus there would be no affected structures by a slight increase in the 25 -year event. The Water Board also requested that the City provide a technical basis for the sediment excavation and new cross sections, as well as, describe, in further detail, the purpose and benefits of the sediment removal. The basis for this work is to reduce flow restriction and scour of the abutments at the Corona Road Bridge. The City has designed the new channel cross section to mimic the original cross section that was created at the bridge's installation, which can be seen in Attachment V. Based on review of project plans and documents of the original Corona Road Bridge design, the river alignment upstream of the bridge was a wide, straight channel. In the existing conditions, the river channel is aligned in such a way that high flows are directed to the northern abutment of Corona Road Bridge. This which has most likely been caused by bank erosion over time that was a catalyst of the buildup of sediment and vegetation. This project proposes to create a straighter, wider, and more uniform channel for higher flows and a narrower low flow channel at the Corona Road Bridge returning river channel to its original cross section design so that it is less likely for sediment and vegetation debris to accumulate and cause a reduction in the flood conveyance capacity. To prevent future bank erosion, proper bank stabilization will be installed as part of the project in the form of proper compaction and revegetation. Certain geomorphic dredging methods, such as excavating a low flow channel with low floodplain benches, have also been considered into the design of the channel cross section to address the warmer months when the river flows are considerably less. With this future sediment removal activities are expected to be avoided. Based on the model, the Project will decrease flood levels up to 0.71 feet (8.5 inches) for the 25 - year storm and 0.9 feet (-11 inches) for the 100 -year storm around the Corona Road Bridge and Industrial Avenue Business Park, with only minimal negative downstream impacts (-1.08 inches) during the 25 -year storm event and no negative downstream effects during a 100 -year storm event. The Water Board stated that the impacts, such as installation of rock within jurisdictional features, are considered fill impacts and were not analyzed in the Initial Study, as well as, the permanent loss of riparian habitat from the removal of large portions of the existing banks. The mitigation measure "GEO-4" has been added to the Geology and Soils section of the CEQA Checklist to address the impacts from the installation of rocks or soils within jurisdictional features. Mitigation Resolution No. 2019-003 N.C.S. Page 18 Measure, 13I0-1: Impacts to waters of the United States, and Waters of the State, also addresses filling of any jurisdictional feature. The impacts to the riparian vegetation were addressed in the Mitigation Measure, 13I0-2: Impacts to Riparian Vegetation. Due to the Water Board stating that they require impacts to be avoided and minimized to the maximum extent practicable before accepting compensatory mitigation, an Alternatives Analysis was added to the CEQA Environmental Checklist after the Project Description to demonstrate that the City has taken the proper steps to avoid and minimize the impacts to the biological habitat. The Water Board listed several alternatives that they may require to be analyzed within the Alternative Analysis. As mentioned above, the Alternatives Analysis has been added to the CEQA Environmental Checklist after the Project Description. The Water Board recommended to the City to evaluate the following mitigation measures to be included into the Mitigated Negative Declaration. Mitigation for Operational Impacts in reference to the post -project maintenance of the detention basins. Prior to deciding on the current design layout of the detention basins, the City analyzed different project options and potential alternate locations to determine the most sustainable design. These alternate options have been inserted into the Alternative Analysis section (page 3 of the IS/MND). Typical maintenance of the basins will include semi-annual site mowing to maintain the proper functionality of the basins, and possibly sediment removal after large flood events. Due to limited amount of funding for Parks Maintenance, the City feels that it will be difficult to maintain the wetland detention basin design, as it would require extra care to monitor that both the wetland and detention basin are both functioning as they should. Mitigation for Fill Impacts has been addressed by adding Mitigation Measure GE04 to the Geology and Soils section of the CEQA Environmental Checklist (page 15 of the IS/MND), and it reads as follows: GEO-4: Any soil or rockfill to be installed within Water Board jurisdiction will include an evaluation of biotechnical methods and habitat enhancement features to be incorporated in order to cnioid and minimize impacts of hardened structures. All rock must be demonstrated to be necessary and appropriately sized through a hydraulic analysis performed by a qualified professional. If biotechnical methods and habitat enhancementfeatures are demonstrated to be infeasible, mitigation will be required at a 1.5:1 ratio at a mininnun. Mitigation for Sediment Removal have been identified in the Geology and Soils section of the CEQA Environmental Checklist. The City has designed the channel section so that it returns the channel to its original design capacity when the Corona Road Bridge was Resolution No. 2019-003 N.C.S. Page 19 constructed with some geomoiphic dredging methods, such as excavating a low flow channel and leaving low floodplain benches, being implemented into the design in order to minimize future sediment buildup. As the Geology and Soils section discusses, the channel banks will be installed in a stable condition and will not exceed 2 to 1 slopes. This project will create a straighter, wider, and more uniform channel for high flows and a low flow channel so that it will be less likely for the sediment and vegetation debris to accumulate. Mitigation for Temporary Disturbance Impacts have been discussed in Mitigation Measures BIO -1, "Impacts to Waters of the United States, and Waters of the State" and BIO -2, "Impacts to Riparian Vegetation." Sonoma County Department of Public Works and Transportation The email details some concerns over the impacts that the project will have on the structural integrity of the Corona Road Bridge over Petaluma River (Bridge No. 200O299) and whether or not the changes would increase the scour potential at the piers and abutments of the bridge. WEST Consultant Inc. performed scour calculations and described them in their revised analysis. The analysis found that under current conditions, pier scour is calculated to be 7.1 feet and under the proposed conditions, the pier scour would be reduced to 6.0 feet. The email also expresses concern regarding the preexisting scour at the abutments. To reduce the risk of future scouring from occurring, riprap is planned to be installed along and around the bridge abutments and will follow the mitigation measure GEO-4 of the Geology and Soils Section. Mr. John Aguiar (Phone Call) Mr. Aguiar inquired about the location of the detention basins, in which the City detailed the location of APN 007-412-033. He also asked what the City plans to do with the soil removed. As the IS mentions, the soil will be off -hauled to an acceptable site. Mr. Aguiar also expressed concern that the sediment removal under the bridge will increase the flood levels in the Downtown/Payran Area. The City has modeled the proposed project with the sediment removed and has found that the water surface elevations are reduced through the Downtown/Payran Area during the 100 -year event. Modeling showed for the 25 -year event slight increase in water surface elevation downstream of Corona Road at the Corona Creek confluence gradually increasing to a maximum increase of 0.09 feet near the constriction weir, and then decreasing again from that point down zero increase near Adobe Creek. Any new additions to the IS/MND, as they have been discussed above, will be indicated in underline in the Initial Study Document. Resolution No. 2019-003 N.C.S. Page 20 CONCLUSION AND STAFF RECOMMENDATION After carefully reviewing the comments on the Initial Study and proposed Mitigated Negative Declaration, the City of Petaluma believes that the environmental document has sufficiently addressed the potential environmental impacts of the proposed Project and does not meet any of the conditions under CEQA Section 15073.5. Therefore, the recirculation of a revised IS/MND or the preparation of an Environmental Impact Report (EIR) is not required. Consistent with the CEQA Guidelines, the added information clarifies the information and analyses in the IS/MND. The City of Petaluma will consider the updates to the Manual and IS/MND, together with this Response to Comments document, prior to adopting the IS/MND. Resolution No. 2019-003 N.C.S. Page 21