City engineer updates water project; staff to develop rules for permeable swales and alternatives

The city engineer updated the commission on the water-replacement program and drainage projects during the Nov. 5 meeting, and raised a planning issue for commissioners: whether to allow alternate, permeable materials in swales on a case-by-case basis.

Staff reported Phase 2 of the water project is essentially complete with water lines installed and roadway resurfacing finished; crews are finishing rear-easement connections and expect completion by the end of the year. Phase 3 of the water-replacement work was advertised for bid and is expected to address the north side areas north of 16th Street.

On drainage, staff said precast drainage structures have been ordered and arrival is expected about a week before Thanksgiving; contractors will begin spot drainage work that includes 10th, 11th and 12th Streets and other problem locations.

Engineers presented alternatives to conventional grass swales in some locations, including open pavers ("grama crete"/turf block), gravel infill or shrubbery for areas where standing water or salt-tolerant conditions limit turf survival. The consultant noted adjacent cities have used similar materials successfully for drainage and parking control.

Commissioners asked staff to draft clear rules and criteria so approvals are not arbitrary and to engage planning and zoning and residents in outreach before adopting any swale exceptions. The manager asked staff to prepare a regulation and to consult with planning and zoning on a case-by-case application program.

No formal ordinance or vote was taken; staff will return with proposed standards, a permitting process and resident outreach plans.