Stormwater Drainage Study

Yakima Training Center, WA




Civil Engineering

Land Surveying


Extensive site surveys to analyze infrastructure

Stormwater modeling for entire basin

Recommendations for drainage improvements

Damaged infrastructure and an inadequate drainage system required a comprehensive study to recommend solutions to long-standing problems.

AHBL was hired by the U.S. Army Corps of Engineers to analyze the drainage system at the Yakima Training Center (YTC) and to recommend solutions to problems of severe flooding, erosion, and deposition within the developed areas of the Cantonment. Although located in an arid climate (average of 9-inches of precipitation per year), the stormwater system at YTC is regularly overwhelmed because of high-intensity, short-duration thunder storms leading to flooding of troop housing and support facilities as well as impacts to downstream neighbors. The existing system consists mainly of ditches and culverts, with some piped areas and some minor infiltration and detention facilities. AHBL surveyed and provided an inventory of the system, delineated basins, and modeled the existing system (5 basins, 485 acres, total). We then developed recommendations for improvements ranging from construction of detention ponds to replacement of culverts and headwalls, to implementation of new street sections. The recommended improvements are intended to bring YTC into compliance with the Washington State Department of Ecology requirements.