St. Helena To Consider Termination Of Phase I Water Emergency

ST. HELENA, CA — The St. Helena City Council accepted a staff recommendation Tuesday to consider terminating the city's Phase I Water Emergency in July once the required analysis is complete.

While the December and January storms provided large quantities of rainwater that resulted in the overtopping of spillways at both Bell Canyon Reservoir and Lake Hennessey — a City of Napa water source for St. Helena — the city's municipal is clear that analysis is required prior to any rescinding of a Phase I Water Emergency, according to a news release this week from Joe Leach, director of Public Works for the city.

The municipal code requires an evaluation of customer water usage patterns, Bell Canyon Reservoir water levels in May, and the projected water balance for the upcoming Fiscal Year starting July 1, 2023, Leach said. The municipal code establishes that the city shall calculate the water supply/usage balance as soon as practicable after the end of each fiscal year (June 30).

The supply/usage balance is the difference between the safe annual yield of the city’s water supply and the total current usage with total current usage being the average usage over the last five fiscal years. The balance is positive, or in surplus, when the safe annual yield exceeds total current usage. The balance is negative, or in deficit, when the safe annual yield is less than total current usage.

The 2011 Safe Yield Committee determined the Safe Yield was 1,950 acre-feet of water prior to the 200 acre-feet increase from the City of Napa was adopted in the December 2011 Water Agreement Amendment. This 2011 Amendment increased the city's allocation from 400 acre-feet to 600 acre-feet.

The current Safe Yield of the City's Water Supply is 2,150 acre-feet. The annual Water Shortage Emergency is determined pursuant to the analytical methodology created by the Safe Yield Committee as identified in its report dated March 17, 2011.

Specifically, this calculation requires compilation and evaluation of multiple data sources including: annual and monthly production volumes for Louis Stralla Water Treatment Plant, Stonebridge Wells and Napa Water; monthly Bell Canyon water levels; operational water in the distribution system; water loss; and delivery to the water enterprise customers. The result of this analysis is the annual water supply/usage balance which then dictates if a water shortage emergency exists.

Based on this prescribed methodology, Leach said, staff will provide an analysis in June, and will provide an outlook and recommendation of the water supply to the City Council in July 2023.

"In the last few years, the weather has been inconsistent with general severe drought conditions interspersed with deluge of rains," Leach said. "We need to adjust to the new normal with climate changes and having less water. This means that even if we are not in a state of water emergency, water conservation needs to continue."

To that end, Leach said, the city will continue to communicate the importance of saving water and will be rolling out incentives. The City Council on Tuesday approved an incentive for greywater systems, the goal being to encourage residents and businesses to reuse as much water as possible thereby minimizing the use of potable water.

The city's current rate study process may also result in a rate structure designed to encourage water conservation by penalizing high usage, Leach said.

Information related to all the parameters necessary to analyze the City’s water supply (e.g. customer demand, supply production, rainfall, Bell Canyon water level, etc.) as outlined in the 2011 Safe Water Yield Committee report and the St. Helena Municipal Code Section 13.04 is included in the staff report for the Feb. 14 City Council meeting.