Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Stormwater topic
No spam. Unsubscribe anytime.
Washington Terrace planning commission holds Low Impact Development training; city code requires LID evaluation
Summary
Planning commissioners received training on Low Impact Development (LID). Presenters reviewed state UPDES requirements, the city's adoption of the Utah LID guide, and the city's expectations for on-site stormwater management and feasibility documentation.
Planning commissioners in Washington Terrace received a training presentation on Low Impact Development (LID), the state and local rules that require new developments and redevelopments to manage stormwater on-site.
A presenter identified in the meeting as the city's GIS specialist reviewed how LID aims to mimic natural hydrology by using infiltration, evapotranspiration and on-site storage so rainwater does not immediately become concentrated runoff. The presentation cited the Utah State Code, the statewide UPDES stormwater permit and the Utah LID guide adopted by the city as the governing framework for projects.
Presenters said the state and permit require on-site volume management for a design rainfall event commonly described in the presentation as the 80th-percentile rainfall event; the goal is to capture and manage that volume primarily through infiltration, evapotranspiration or rainwater harvesting. Redevelopment projects must demonstrate net gain in on-site retention or reduce runoff when adding new impervious surface, the presenter said.
Washington Terrace city code now incorporates the Utah LID guide. The city requires a stormwater quality report using the guide's template to be submitted to the city engineer with every development plan. The code lists preferred LID practices to be used to the greatest extent feasible, including rain gardens and bio-retention cells, bioswales and landscape filter areas, permeable pavement, infiltration trenches or basins, green roofs and rainwater-harvesting systems.
The presenter emphasized the city's feasibility standard: projects must implement LID practices to the greatest extent feasible given site-specific constraints. The code ties feasibility to documented site conditions such as high groundwater, poorly draining soils (for example, dense clay), or other engineering constraints identified by the city engineer. The presenter told commissioners that developers may propose alternative or innovative practices but must document why conventional LID techniques are not feasible at a particular site.
The presentation included local examples of LID features in Washington Terrace — parking-lot islands with gravel and cobble designed to retain water and promote infiltration — and staff encouraged commissioners to expect on-site retention measures as part of plan review. The training concluded with a reminder that LID can reduce conventional storm-drain infrastructure needs, recharge groundwater and improve water quality when properly designed and maintained.
