Treasure Valley Crossing, Marketplace Stormwater
Keller Associates completed the planning, design, and assisted with construction management of the Treasure Valley Marketplace and Treasure Valley Crossing storm drain improvements. The two shopping centers, located adjacent to each other, consist of 115 acres with expansion capabilities of an additional 40 acres. Additionally, the storm systems received approximately one-half of the storm water ﬂows from the new I-84 Karcher Interchange.
Two large inﬁltration basins were designed to contain the 100-year storm event while releasing stored water into the groundwater through sand ﬁlters.
The Marketplace inﬁltration basin includes a biological swale to absorb pollutants from the asphalt runoff. The inlet pipe discharges into the biological swale which treats the ﬁrst “ﬂush” from the asphalt parking areas. The swale overﬂows to the inﬁltration basin which can completely inﬁltrate the 100-year storm event within 24-hours after the storm.
The Crossing inﬁltration basin includes two large custom-built sand and grease traps. It also included a concrete holding trough to receive the ﬁrst “ﬂush” from the asphalt parking areas. To reduce maintenance costs, the sand and grease traps were centrally located upstream of the basin. The concrete trough was located at the bottom of the basin and an access road was designed so that a front-end loader could remove settled debris.