Rehabilitate Tuolumne Meadows Water Distribution System

This project was evaluated and selected for implementation in the 2014 Record of Decision for the Tuolumne River Plan Environmental Impact Statement (EIS)(PEPC 14043). The proposed project has been designed following recommendations set forth in the EIS Selected Alternative which states in part:

This report summarizes the results of the Schematic Design phase of the project to replace the TM WDS. This project will replace the 4-inch 91-year-old WDS and meet current National Fire Protection Association standards for fire flow during a range of seasonal flow conditions and will include the following:
• Construction of a new water storage tank located near the existing water storage tank to connect to the water treatment plant
• Construction of a new distribution water line from storage tank to the existing visitor center, including a lateral to the corral and
stables
• Providing service connections from the trunk line to the ranger station, employee housing, store, lodge shower, TM campground,
new visitor center, existing Wastewater Treatment Plant (WWTP), new WWTP, and existing visitor center
• Installation of new fire hydrants and meters
• A new tank will be constructed on the existing site while maintaining operation of the
existing treatment processes
• Construction of a new gate at the fork in Lodge Road
• Abandoning the old distribution line in place
• Demolishing the existing or retrofitting the existing tank

Rehabilitate the Tuolumne Meadows water distribution system that provides an average of 34,000 gallons of potable water a day and a daily maximum of 73,000 gallons to NPS facilities, visitors, visitor campgrounds, the local community, concession employees and NPS employee housing. Specific work will include: 1) Replace 25,000 linear feet of outdated water line, including distribution mains and laterals to all buildings and facilities. Water line sizes will vary as required, likely between 1-inch to 8-inches. Pipe material will be PVC, HDPE and DIP. 2) Replace 100,000 gallon above grade water tank with a larger above grade tank (size to be validated during design). The existing tank is steel; new tank will likely be steel. 3) Replace 8 fire hydrants. 4) Install water meters at all facilities (approximately 60 total). All work to be performed by contract.

Tuolumne Meadows is located at the East entrance to Yosemite National Park, which is visited by 4 million people annually. Replacing the outdated piping, will ensure providing potable water that complies with the current state and federal regulations and provide useable water for basic sanitation that reduces potential impact to area surface water that feeds the Tuolumne River, a designated Wild and Scenic River.

PUBLIC ANNOUNCEMENT OF DRAFT FLOODPLAIN STATEMENT OF FINDINGS FOR PUBLIC REVIEW:

The NPS has prepared a draft Floodplain Statement of Findings (FSOF) for the Tuolumne Water Line Distribution rehabilitation project. Following PM 77-2, the actions associated with the proposed alternative are Class I, or noncritical actions. The regulatory floodplain for Class I actions is the 1 percent annual exceedance probability flood, also referred to as the 100-year flood or the base flood (DO #77-2).

Following EO 13690, any proposed action that involves federal capital investment must include a Federal Flood Risk Management Standard (FFRMS) for new construction, substantial improvement, or repairing substantial damage. Per the Federal Emergency Management Agency's implementing guidelines for EOs 11988 and 13690, Freeboard Value Approach establishing FFRMS flood elevations is employed for this proposed action. This method adds 2 feet to the BFE. Therefore, the regulatory floodplain for the proposed action is the 1% annual chance (100-year) flood elevation plus 2 feet.

The purpose of the FSOF is to review the proposed project in sufficient detail to provide an accurate and complete description of the flood hazards and risks associated with the action, describe the effects on floodplain values from the proposed action, and evaluate mitigation measures to ensure the action complies with EOs 11988 and 13690 and Director's Order 77-2.

The public may review this draft FSOF and provide comments regarding its contents and findings over a fifteen-day public comment period that will begin on September 27, 2024. The draft FSOF may be accessed, and written comments may be submitted at the National Park Service Planning, Environment, and Public Comment webpage for this Site.