The four-year framework starts in July 2013 and follows on from a previous term arrangement that generated £50m in revenues for the JV last year. There is also scope for a two-year extension.
Galliford Try and Black & Veatch will work primarily on flood and coastal erosion risk management projects for the agency. The JV will also be available to other public sector organisations such as local authorities, internal drainage boards and the Welsh government.
The Environment Agency has intends to invest £2.5bn over the next 10 years to reduce flood risk nationally and secure wider environmental and social benefits.
Galliford Try chief executive Greg Fitzgerald said: "We envisage that the new framework presents a similar or even better business opportunity than we currently have with the Environment Agency. This key appointment further enhances our reputation for innovation and engineering expertise within the flood and coastal work sector, and recognises our commitment to providing customers with certainty of delivery and cost within a collaborative working approach."