Prescott City hears 15% design review for SR 89 widening and effluent pipeline after repeated pipe failures

Prescott City Council held a study session Aug. 26 to review 15% design concept plans for the SR 89 corridor between Willow Lake Road and Fippin Trail, and to discuss replacing a failing 24‑inch effluent pipeline that runs under the road.

Public Works Director Gwen Roich said the immediate priority is the pipe, which the city has recorded more than eight failures in the last 2½ years and about 10 in five years. “The number 1 priority is the pipe. That pipe continues to fail,” Roich said, noting past closures that disrupted travel.

The design review presented three top alternatives developed by consultant Kimley‑Horn: Alternative 3B, a five‑lane widening through the corridor (budgetary estimate $36.7 million); Alternative 5B, a five‑lane/partial four‑lane barrier configuration ($35.5 million); and Alternative 2B, the top non‑widening option ($25.2 million). All alternatives include safety improvements such as extended tapers at the Fippin roundabout, consolidated access points, improved sight lines and right‑out/left‑in access controls near Willow Lake.

Nut graf: The study session focused on whether to use the construction window created by replacing three 24‑inch pipes in the corridor to also widen SR 89, or to rebuild the pipeline while keeping the current two‑lane cross section. Staff said widening would allow staged construction that preserves traffic flow; a non‑widening approach would require longer closures during pipe work.

Staff, engineers and council members discussed public input, modeling methods, environmental concerns and funding. Tim Sherwood, the city’s capital program manager, described the procurement and consultant team: Kimley‑Horn led design, with Lion Engineering and…