Planning for New York City's Water Supply Resiliency

The NYC Department of Environmental Protection (DEP) is responsible for supplying clean drinking water to more than 8 million city residents and 1 million upstate customers. This is achieved through careful and coordinated management of the city's three surface water supply systems: the Catskill, Delaware, and Croton systems. Recognizing the need to protect the long-term viability and overall resilience of the water supply system, DEP continues to make systematic and sustained investments in its critical infrastructure. DEP developed the water for the future (WFF) program to address significant leakage in a critical piece of infrastructure, the Delaware Aqueduct, which currently conveys 50% of the water demand. WFF involves construction of a bypass tunnel around a leaking section of the Rondout-West Branch Tunnel (RWBT), a portion of the Delaware Aqueduct. To connect this bypass tunnel to the existing system, the Delaware Aqueduct will be taken offline for a period of up to 8 months. During this period, DEP would rely on the existing flexibility within the water supply system. DEP is pursuing a series of projects known collectively as upstate water supply resiliency. The proposed components include: the Catskill Aqueduct repair and rehabilitation to restore conveyance capacity; a temporary water supply operating protocol to prepare for the RWBT shutdown; and inspection and repair of the RWBT including decommissioning of the bypassed section. This paper would highlight the innovative planning involved in this program to minimize risks, avoid environmental impacts and ensure water supply for the next generation of New Yorkers.