City of St HelenaUpper York Creek Ecosystem

Restoration Project

April 28, 2015St. Helena City Council Meeting

Background

Background• 1900 – Dam constructed

• 1930’s - Ceased use as a water source

• 1965 to 1992 – Four incidents of accidental, catastrophic release of sediment resulting in fish mortality

• July 28, 1992 – Accidental sediment discharge during maintenance results in complaint filed with Napa County District Attorney

Background• March 2002 – City formally abandons right to

divert water from York Creek into Upper York Creek Reservoir

• 2004 – Downstream diversion to Lower York Creek Reservoir removed

• February 2006 – Agreement with NOAA to pay $70,000, and $70 per day the dam is in place after December 1, 2009

• September 19, 2006 – Notice of Preparation of Draft EIR

Background• October 18, 2006 – Initial public comment period

closed and no comments received

• April 19, 2007 – City noticed for additional comments through June 4, 2007. No comments received.

• May 31, 2007 - No comments received. City noticed for additional comments through July 25, 2007

• July 26, 2007 – One comment received. City sent email to residents on Bieber Road and extended public comment period to August 29, 2007

Background• August 30, 2007 – City noticed for additional

comments through October 15, 2007.

• October 2007 – Public comment period extended to November 14, 2007, due to request from State Water Board

• September 2006 to October 2007 – Four public meetings were held

• August 2010 – Agreement with NOAA to remove the dam and establish fish passage. Beginning October 31, 2012, City will pay NOAA $70 per day that dam is in place.

Project Scope

• Modify dam to allow fish passage

• Remove accumulated sediment

• Maintain stability of Spring Mountain Road

Project Alternatives

• Full Removal

• Small Notch Alternative (preferred alternative)

• Fish Ladder

Project Alternatives

Project ScopeSmall Notch Alternative

DAM EMBANKMENT

Project ScopeSmall Notch Alternative

EXIST. GROUND (DAM)

PROPOSED GROUND

Project Scope

• Current funding:

Funding Source AmountSFWQIF $ 987,876

Proposition 84 IRWMP

$ 800,000

City Bond Funds $ 3,016,349Unidentified $ 1,695,775

Total Project Cost $ 6,500,000

Project Impacts• Significant and Unavoidable (4)

1. Aesthetics – Placement of soil at Lower Reservoir may result in a change in the water surface area as viewed from above

a) Mitigation – Plant native vegetation

2. Cultural Resources – Dam is considered eligible for listing in the National Register of Historic Places and California Register of Historic Resources.

a) Mitigation – Provide graphic and written documentation of the dam’s significance on the City’s website and displayed in a City building.

Project Impacts• Significant and Unavoidable (4)

3. Hydrology & Hydraulics – Sediment aggradation in Lower York Creek may increase the frequency and severity of flooding

a) Mitigation – implement a channel monitoring program, causative factors analysis, and program to improve channel capacity and promote sediment transport.

4. Noise – Temporary increase due to construction activities

a) Mitigation – Work during daylight hours and efficiently schedule activities to minimize hours of noise

Action• Open a public hearing for comment

• Certify the Environmental Impact Report

• Adopt CEQA Findings and Statement of Overriding Considerations

• Adopt Mitigation Monitoring and Reporting Plan

• Authorize staff to proceed with securing final funding and development of Project design and construction bidding documents

Future

• Identify and apply for grant funding to secure funding for current shortfall

• Prepare final design documents