City of Renton
Project: Stormwater Planning
Location: King County, Washington
Concerns about drinking water quality prompted the City of Renton to protect
its supply wells using a variety of measures: delineating wellhead protection
areas, designating a sole source aquifer, and issuing an ordinance requiring
aquifer protection. One important aspect of these measures was addressing
stormwater issues; consequently, the City decided to explore options for
managing its stormwater.
Renton’s proactive groundwater management approach challenged us
to explore protective measures that have not yet been widely adopted in
the industry. We had to balance the benefits of stormwater infiltration
with the need to protect nearby water supply wells.
We assessed the effects of stormwater infiltration on groundwater quality
and groundwater levels using a digital flow model. This model allowed
us to predict the impacts of various stormwater management scenarios on
Renton adopted our recommendations to prohibit stormwater infiltration
in areas directly overlying supply aquifers. We identified other areas
where stormwater infiltration could be used to recharge groundwater.