10/2/19 SA SAN F FRANCISQ SQUITO C CREEK S F C J PA . O R G J O I N T P O W E R S A U T H O R I T Y BOARD OF DIRECTORS MEETING Palo Alto City Council Chambers September 26, 2019 at 3:30 p.m. September 26, 2019 Board of Directors Meeting Agenda Item 5: PUBLIC COMMENT Individuals may speak on any topic for up to three minutes; during any other Agenda item, individuals may speak for up to three minutes on the subject of that item. 1
10/2/19 September 26, 2019 Board of Directors Meeting Agenda Item 5: REGULAR BUSINESS – EXECUTIVE DIRECTOR’S REPORT a. Certify the Final Environmental Impact Report for the Upstream of Highway 101 Project: Consider approving Resolution #19-9-26-A, certifying the Final Environmental Impact Report for the San Francisquito Creek Flood Protection, Ecosystem Restoration, and Recreation Project Upstream of Highway 101; making findings pursuant to the California Environmental Quality Act; adopting a Statement of Overriding Considerations; and adopting a Mitigation Monitoring and Reporting Program With the Bay-Hwy. 101 Project complete, the flood picture upstream of Hwy. 101 Flow Current Conditions: After proposed project is built: Max flow to reach Pope-Chaucer = 7,500 Max flow to reach Pope-Chaucer = 7,500 < 5,800 should not flood anywhere < 7,200 should not flood anywhere > 5,800 floods at Pope-Chaucer Bridge > 7,200 floods at Middlefield Bridge only > 7,200 also floods at Middlefield Bridge 2
10/2/19 Opportunities to review and comment on the project & EIR The initial Upstream of Hwy. 101 project approach in 2013 was to provide 100-yr protection through work between Hwy. 101 and Pope-Chaucer Br. In public meetings in 2013 and 2014, the SFCJPA heard from many that this approach would have too many impacts on the Creek in that area. That led the SFCJPA to develop a two-pronged approach with fewer permanent impacts to the Creek in the neighborhoods: 1. Enable the channel downstream of Middlefield Bridge to contain the maximum flow that could get under that bridge (equals 1998 event); restore habitat; and not preclude additional protection upstream. 2. By detaining floodwater upstream of Hwy 280 when flows exceed the capacity at Middlefield Bridge, eliminate overtopping at that bridge during 100-yr event, and eliminate the FEMA floodplain everywhere. San Francisquito Creek Flood Protection, Ecosystem Restoration, and Recreation Project The SFCJPA’s Approach M i d d l e f i e El Camino Real l d Pope-Chaucer Br • Increase capacity by ~4,500 cfs to a total of 9,400 (max flow with sea level 10 ft. above current high tide) Downstream of Middlefield is • Increase capacity by 1,700 cfs to a total of 7,500 protected against any flow, regardless of storm duration • Detain 800-1,000 cfs during storm event Start filling just before overtopping begins downstream; prevents flooding during 100-year event 100-year event = 8,150 at flood-prone Pope-Chaucer Bridge 3
10/2/19 Modeled floodplain of 1998-sized event Today Post-project (downstream of Middlefield Road, the creek should not overtop) In December 2016 the SFCJPA announced a revised project and planned EIR through a Notice of Preparation. As this project and EIR were developed, when it was most valuable, the SFCJPA heard public comment at multiple presentations to each City Council, dozens of SFCJPA Board meetings, and the formal public meetings in: • Jan. – Feb. 2017: 4 scoping meetings (2 in MP , 1 in each PA & EPA) • October 2017: 2 facilitated workshops and a tour of potential project sites • April – June 2019: A public hearing in each city on the Draft EIR; comments The Final EIR added clarifications were accepted for a period almost 50% and information requested in longer than what CEQA requires. comments on the Draft, but no significant changes or new impacts 4
10/2/19 Outreach for the Draft EIR public hearings • 13,000 postcards mailed to nearby properties • Next Door posts in all three cities • E-blast to people signed up to receive these • Websites and website calendars • Print ads: Palo Alto Weekly, Almanac, Palo Alto Daily News, SMC Daily Journal • Presentations: Menlo Park & East Palo Alto City Councils, SFCJPA Board • Announcement: Palo Alto City Council Another look at what’s in the EIR: Alternatives considered 1. No action / no project 2. Replace Pope-Chaucer Br. & railing at Woodland & Univ., widen bottlenecks 3. Construct one or more detention basins in upper watershed 4. Construct an underground bypass culvert 5. Replace Pope-Chaucer Br. & railing at Woodland & Univ., build floodwalls 6. Construct a culvert through Pope-Chaucer Bridge 7. Construct a channel around Pope-Chaucer Bridge 8. Replace Pope-Chaucer with a bridge for bikes and peds only 9. Remove and do not replace Pope-Chaucer Bridge 10. Increase the removal of debris and non-native vegetation 11. Deepen the channel 12. Construct multiple small-scale water detention facilities 13. Increase incentives for Low Impact Development (LID) 14. Utilize overland floodways 15. Construct a new pump station 16. Construct a new Ladera Dam 17. P-C Bridge, widen bottlenecks (Corps objective smaller flow + freeboard) 5
10/2/19 Another look at what’s in the EIR: Alternatives analyzed Alternatives that met project objectives and are feasible: • Replace Pope-Chaucer Bridge, replace University Ave. wooden parapet extension, and widen channel bottlenecks downstream • Replace Pope-Chaucer Bridge, replace University Ave. wooden parapet extension, and build floodwalls downstream • Construct Webb Ranch Detention Basin Alternative • Construct Former Nursery Detention Basin Alternative Floodwall Alternative • Replace Pope-Chaucer • Construct floodwalls not more than 2 feet high • Replace wooden parapet extension at Woodland & Univ. and match PA top of bank, widen creek at W. Bayshore Closed for ~9 months during construction Project of the City of Palo Alto to replace Newell Bridge 6
10/2/19 Potential Upstream Detention Sites d n a . d S R l ey Hill Rd l i H d n a S ¦ § ¨ 280 Alpine Rd. d R e n i p l A Searsville Dam Former Plant Nursery and Reservoir Detention Basin A l i s o Webb Ranch W Detention Basin L a k e s h o r e D r One or more basins could be constructed. Searsville Reservoir would begin to fill when flows exceed the capacity of a new orifice/tunnel in the Dam. Webb and Former Nursery basins would begin to fill before flows exceed the capacity of Pope-Chaucer Bridge. Former Nursery site Webb Ranch site 7
10/2/19 Why not focus only on upstream detention to achieve objectives? • To equal the flood protection benefit of the proposed project, detention would have to be built at Webb Ranch and Searsville, and possibly also at the Former Nursery site • Constructing all three facilities without replacing Pope-Chaucer would likely not protect against the 100-year storm event • Prolonged storm events can fill a detention basin, after which it provides no flood protection benefit • The timeline to construct these basins is longer and uncertain (As discussed during the Aug. 22, 2019 SFCJPA Board meeting, we intend to secure info needed to evaluate potential detention basins) With the Bay-Hwy. 101 Project complete, the flood picture upstream of Hwy. 101 Flow Current Conditions: After proposed project is built: Max flow to reach Pope-Chaucer = 7,500 Max flow to reach Pope-Chaucer = 7,500 < 5,800 should not flood anywhere < 7,200 should not flood anywhere > 5,800 floods at Pope-Chaucer Bridge > 7,200 floods at Middlefield Bridge only > 7,200 also floods at Middlefield Bridge 8
10/2/19 How the does Searsville relate to flood protection alternatives? Potential flooding during 100-year flow (estimated in cfs at Pope-Chaucer) No Detention at Proposed Proposed SFCJPA Webb & SFCJPA project and Project Former project Webb Ranch Nursery Searsville not 2,350 1,050 650 No flooding modified, Res. (flooding only (250 excess full of sediment at Middlefield) capacity) (no fish passage) Remove dam 3,450 2,150 1,750 850 (enables fish (flooding only passage) at Middlefield) Stanford’s dam 1,450 150 No flooding No flooding orifice approach (250 excess (1,150 excess (fish passage) capacity) capacity) Flooding at and downstream of Middlefield Road Bridge Proposed Project • Replace Pope-Chaucer • Widen channel where needed by removing concrete • Replace wooden parapet extension at Woodland & Univ. and match Palo Alto top of bank Closed for ~9 months during construction City of Palo Alto project to replace Newell Bridge 9
10/2/19 Existing Pope-Chaucer Bridge Menlo Palo Park Alto Proposed Replace a large concrete terrace structure on the East Palo Alto bank with a natural creek bank 10
10/2/19 Replace wooden Univ. Ave. Bridge parapet extension on Woodland Ave. and match Palo Alto side top of bank Widen three areas between Newell and Euclid where sacked concrete lines the Palo Alto creek bank 11
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