Marina Coast Water District (MCWD) recently completed construction of 7.5 miles of 24-inch diameter high pressure, zinc coated ductile iron transmission main and a 2.0 MG reservoir in the former Fort Ord Army Post as part of the Regional Urban Water Augmentation Project. Unique challenges included excavating in areas potentially containing unexploded ordinance (bombs), poorly graded coarse soil (beach sand), and existing utility systems constructed without record drawings. Additional challenges included establishing land ownership for properties in transition from federal to local agencies, an aggressive project schedule, conflicting permitting requirements, and complying with federal funding requirements. This paper describes the MCWD's approach to mitigating these challenges before construction and overcoming these challenges during construction. Selecting the zinc coating and designing the transmission main for high pressure are also discussed. Finally, the paper reviews the project's successes and failures, lessons learned, and recommendations for working in former military bases.