Online Design Tool Used to Design Complex Detention System

Nov. 8, 2021

A 2,000-unit self-storage facility being built in Vancouver, WA required a robust stormwater management system. The original design called for Filterra Bioretention systems to treat the water before being conveyed to a stormwater pond. However, the county required a more stringent discharge limit which drove the pond to be too large for the given site.

Engineers contacted Contech to provide an underground solution to fit a unique footprint. A uniquely-shaped 72-inch diameter corrugated metal pipe underground stormwater detention system was designed to store over 35,000 cf (262,000 gal) of stormwater. The system was carefully designed to avoid two proposed buildings on an oddly-shaped parcel.

Using Contech’s newly redeveloped ‘Design Your Own Detention System’ (DYODS) tool, the Contech design engineer carefully drew the detention system over a superimposed site plan, ensuring the proposed shape was free of utility and foundation conflicts. This effort combined the usual computing and drawing automation of Contech’s detention design tools with the viewer-friendly visuals of the new DYODS features to deliver a detention package to the engineer of record that was thorough and polished.

Three Filterra Internal Bypass Curb were installed at various locations to capture and treat the stormwater before entering the underground detention system. The Filterra Internal Bypass Curb incorporates a curb inlet treatment chamber and internal high flow bypass in a single structure. This eliminates the need for a separate bypass structure and enables placement in a “sag” or “sump” condition.

“The Hazel Dell premier storage project presented a lot of stormwater challenges,” said John Megrditchian, P.E., Project Manager, at AAI Engineering. “We were working with a limited footprint but still needed to maintain Department of Ecology’s stormwater detention standards. Contech’s CMP provided the perfect stormwater storage solution for a site that had a tight footprint and even tighter stormwater regulations. Due to its customizable arrangement and storage efficiency we were able to meet the site needs.”

Editor's Note: Scranton Gillette Communications and the SGC Water Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the editorial teams of Water & Wastes Digest, Water Quality Products and Storm Water Solutions.