Challenges of Constructing Urban Green Infrastructure

摘要

DC Water's Long Term Control Plan, known as the DC Clean Rivers Project (DCCR), is a comprehensive effort to improve the quality of the District's waterways through the reduction of combined sewer overflows (CSOs). In addition to improvements to the existing collection system and the construction of large diameter tunnels, DC Water's consent decree includes requirements to construct green infrastructure (GI) to maximize CSO control. Construction of the first two GI projects was recently completed in October 2018 and March 2019. These two contracts include the construction of 121 separate GI facilities in Northwest Washington, D.C. Implementing these projects within a highly urban environment led to special challenges to construction. Besides more typical construction management challenges, the urban setting meant several factors needed to be addressed to successfully implement GI. These include substantial utility coordination, phased sequencing, maintenance of traffic and safety, stakeholder interaction, and outreach. This paper describes the obstacles and issues specific to constructing urban GI, and illustrates management techniques employed by DC Water and RK&K to effectively implement these projects.