Decorah reviews 30% design for Hively Street with roundabout, shared path and utility upgrades

MSA presented the 30% conceptual design for Hively Street Phase 2 and sought council feedback on key elements including a proposed compact roundabout at the River/Claiborne/Hively intersection, pedestrian refuges, and multimodal connections.

The presentation by James Waters, project manager for MSA, outlined a roughly 1,500‑foot corridor starting just west of the river and continuing east to State Street. Waters said the plan would narrow Hively Street to a consistent 31 feet curb‑to‑curb, provide 12.5‑foot travel lanes, and add a 10‑foot shared‑use path on the north side east of the roundabout to tie into the citywide bike trail. "We feel like a roundabout is a good intersection control solution here," Waters said, citing nearby civic uses including city hall, the fire department and a planned elementary school.

A key design element is a compact roundabout sized between about 80 and 100 feet in diameter with an 11‑foot mountable truck apron to accommodate school buses and larger vehicles. Waters said the roundabout is sized to handle traffic volumes well above the corridor’s current average daily traffic of about 4,300 counts taken last October. The design includes splitter islands that can function as pedestrian refuge islands and curb geometry intended to reduce travel speeds.

Utilities and stormwater were a major focus. The project includes water‑main replacement, sanitary sewer reconstruction and a stormwater concept that collects flows at the intersection and routes them east to a low point and an existing mill race arch culvert. Staff told council the sanitary sewer segment currently has sections of vitrified clay from the 1930s and would need to be upsized from 18 inches to 24 inches to meet contemporary standards and self‑cleaning velocity. Waters noted manhole depth and grading constraints and said coordination with the elementary school’s site plan will be needed to ensure adequate cover and serviceability.

Councilmembers asked about roundabout diameter, design speeds, whether the design might encourage faster driving, and how the proposed alignment would affect parking near the post office. Waters said the design speed is based on the posted 25 mph corridor and that the narrower typical section and absence of on‑street parking were intended to preserve traffic‑calming benefits. He confirmed the current design removes several on‑street parking stalls near the post office to make room for the 10‑foot path and connectivity features.

Council direction and next steps: councilmembers asked staff to refine the 60% plans with clarified curb and sidewalk cross sections, demonstrate how the multiuse path will connect with the new elementary school, and show refined stormwater and sanitary details once the school’s site plan is available. Waters said MSA will return with a 60% update that includes painted bike markings, refuge island details, and center‑island landscaping options.

The council’s input focused on safety for students and bicyclists, ensuring the sanitary design has sufficient cover and insulation, avoiding design choices that would encourage higher travel speeds, and balancing sidewalk/parking tradeoffs in the downtown tie‑in. The 60% submittal will also show options for the roundabout center island (grass knoll, cut limestone with native grasses, or a site for future public art) and stormwater plantings intended to be low maintenance and deer resistant.

What’s next: MSA will incorporate council feedback and expect to return at the 60% design milestone with updated drawings and cross sections for final comment before 90%/final design.