Irrigation facility relocations along the Arizona state route 85 corridor

In 1999 the Arizona Department of Transportation (ADOT) began improvements along the State Route 85 (SR85) corridor between Gila Bend and Interstate 10 (I-10). At the time SR85 was a two-lane highway that carried a large volume of truck traffic between Interstate 8 near Gila Bend and Phoenix. The SR85 roadway improvements project is broken into phases. The first phase includes the construction of frontage roads and using these roads as a divided highway. Once the divided highway is completed, the final freeway cross section will be constructed between the frontage roads. The project impacted existing irrigation facilities for three irrigation districts located between the Gila River and I-10; the Arlington Canal Company, Buckeye Water Conservation and Drainage District (BWCDD) and Roosevelt Irrigation District (RID). The roadway improvements impact three main canals, turnouts from the main canal, main canal check structures, delivery structures, laterals, groundwater wells and tailwater collection systems. Three miles of irrigation facilities relocations were completed in various phases between 1999 and 2009. Total construction cost as of May 2009 is about $9.4 million. ADOT is currently working on 30% design plans for the main line between the Gila River and Broadway Road. The irrigation districts are coordinating with ADOT regarding the impacts to the irrigation facilities. In this paper we present the institutional and functional constraints to infrastructure modernization in an urbanizing area with historic irrigated agriculture. This process was complicated by the need to continue to operate the irrigation delivery facilities on an almost year-round basis.