Farmington council adds Farmington Lake spillway‑raise to ICIP, seeks grants for $4 million project

The Farmington City Council voted unanimously to add a proposed Farmington Lake spillway‑raise project to the city’s Infrastructure Capital Improvement Plan (ICIP) and to authorize staff to pursue grant funding and further design work.

Mark Hathcock, who presented the engineering overview, described the proposal as a targeted five‑foot raise of the spillway (a controlled discharge structure) rather than a full dam height increase. Hathcock said the design would be an accordion‑style (labyrinth) spillway that increases discharge capacity while fitting the constrained site. He estimated the schematic cost at about $4,000,000 and said the raise would add roughly 1,150 acre‑feet of storage — about a 15% increase in capacity — which the presentation converted into an increase in storage measured in days (an approximate 34‑day increase on average, with larger increases at peak demand conditions).

Hathcock noted the project is at approximately 30% design and that grant sources under consideration include the Water Trust Board and other regional water funding programs. He also said the project would require relocating or redesigning sedimentation basins, docks and portions of adjacent park infrastructure; staff said the estimated cost allowance includes those relocations. When asked, staff said that some state lease land lies nearby but that the five‑foot raise as conceptually presented would stay within currently leased or city property and should not require additional lease area.

Council discussed the project’s benefits and next steps. Council members asked whether the city had sufficient water rights to fill added capacity; staff answered that Farmington holds diversion rights exceeding current storage, meaning increasing capacity would allow the city to make fuller use of water supplies rather than allowing unused diversions to pass downstream. Council also asked about the timeline to fill the additional five feet; staff said the filling period would depend on river flows but could be a matter of months once construction is complete.

Councilor Rogers moved to adopt the ICIP amendment adding the spillway‑raise project and council approved the resolution unanimously. Staff will pursue grant funding, complete design to 100 percent, and return to council with financing and construction plans as they are developed.