Consideration and Approval of Ratifying the Grant Agreement:  Ratifying the Grant Agreement between the City of Flagstaff and the U.S. Department of Agriculture, Natural Resources Conservation Service, Emergency Watershed Protection Program for the Schultz Creek Sediment and Flood Detention Basins Project.

This ratifies the City Manager's acceptance of the NRCS Notice of Grant and Agreement Award which provided funding for the Schultz Creek Sediment and Flood Detention Basins Project.

The Grant Agreement is for a total project cost of $3,176,222 ($2,408,180.75 Federal share / $768,041.25 City share). The award includes Construction and Technical Assistance costs.

The project is budgeted in account number 206-08-331-1258-0-4364 for FY 2022. Funds will be expended against the grant project account number 206-08-385-3517-0-4442, project number WS3517B.

This ratifies the City Manager's acceptance of the NRSC Notice of Grant and Agreement Award which will provide Emergency Watershed Protection funds to provide protection from flooding, restore the hydraulic capacity to the natural environment to the maximum extent practical, and reduce threats to life and property.

Priority Based Budget Key Community Priorities and Objectives

• High Performing Governance - Enhance the organization's fiscal stability & increase efficiency & effectiveness
• Environmental Stewardship - Promote, protect & enhance a healthy sustainable environment & its natural resources 

No.

• Ratify and accept the Grant Agreement which will provide funding to complete the project.
• Not ratify and accept the Grant Agreement and the funds will be returned and the project will be canceled.

Beginning on June 12, 2022, the Pipeline Fire severely burned approximately 26,532 acres of ponderosa pine, grass and brush in an area north of Flagstaff, which negatively impacted soil structure and water retention within the designated Flagstaff area watershed footprint. The resulting burn scar created a severe post-fire flooding environment and risk potential to the community.

The Pipeline Fire burned over 1,000 acres of the Schultz Creek watershed in June 2022, mostly in severe burn conditions. The expected post-fire flood potential has increased by three orders of magnitude with preliminary modeling indicating near 900 cubic feet per second of devastating flood flows that are roughly a 25-year storm through portions of north Flagstaff with eventual impacts to downtown Flagstaff. This proposal addresses over half of the anticipated flood volume through a series of detention basins on a 20-acre City-owned parcel at the upstream boundary of City limits. This project would be the highest priority for the City as it will greatly reduce the flood potential through several thousand homes, critical infrastructure such as Highway 180, and the historically disadvantaged Southside community.

This project will reduce debris load that has historically negatively impacted existing stormwater infrastructure during storm events, a serious concern for this watershed based on previous scientific studies. Initial sediment modeling, pre-Pipeline Fire, indicates over 100,000 tons of sediment available for transport over the next several years due to large sediment storage areas within the Schultz Creek streambed (Stempniewicz, 2014). This project will mitigate the sediment and debris flows that enter neighborhoods and will be a tremendous benefit to the community.

A federal assistance request was submitted on June 24, 2022 to NRCS.  Based on a site visit with NRCS and City staff, NRCS requested submission of a Damage Survey Report (DSR) that was submitted on July 8, 2022. Upon their review of the DSR, the City was requested to submit a standard grant application which was completed and sent on July 27, 2022. In addition, on July 27, 2022, NRCS notified the City that they would be providing $2,304,123.75 in Financial Assistance and $104,057.00 in Technical Assistance for a total of $2,408,180.75 in federal funding.

The Schultz Creek Sediment and Flood Mitigation Detention Basins project will mitigate post-wildfire flooding from the Pipeline Fire, by ways of attenuating the peak flows and providing an area for larger debris to deposit outside the existing stormwater infrastructure. The Pipeline Fire burned over 1,000 acres of the Schultz Creek watershed in June 2022, and resulted in an increased risk of post-wildfire flooding for neighborhoods downstream, including Coyote Springs, Coconino Estates, Downtown and the Southside. The project will detain over 40 acre-feet of water and sediment, thereby reducing life and safety threats as well as the risk of post-wildfire flooding.

The project will be located on a 20-acre parcel of City-owned land at the northeast corner of the intersection of E. Mt. Elden Lookout Rd and Schultz Pass Rd. The location of this parcel allows for significant peak flood attenuation, detention of flood waters and retention of large debris before they flow into existing stormwater infrastructure or downstream into neighborhoods. Flood modeling shows considerable post-wildfire flooding impacts to the 20-acre parcel, regardless of the installation of the detention basins, with a recent rain event resulting in significant scouring and other erosion impacts at this location. This project will help ensure the flooding impacts through the parcel will be mitigated through engineering solutions which in turn will protect the parcel from further scour.

This Grant Agreement will fund the project which will help reduce / relieve imminent threats to life and property cause by post wildfire flooding.