Water is the most important resource for maintaining life, the importance of which is magnified in the arid Southwestern United States. Due to scarce rainfall, hot temperatures, and a sparse landscape, initial human development in the region was limited to areas where water could be easily harnessed (Rivera 2002:1). During the early 1500's, Spanish conquistadors in Mexico pushed north into modern day New Mexico and Colorado. Familiar with the dry climate, Hispano settlers began building widespread irrigation systems to cultivate the once unusable arid lands (Hicks et al. 2003:410). Water resources were shared equitably among the community via a canal system, and anyone that wanted water had an opportunity to use this common-pool resource. The canal system as well as the social institution that governs the administration of water among the community of irrigators is referred to as an "acequia" (Rodriguez 2006:2). Many of the acequia communities of New Mexico and Colorado have proven to be very durable and are still functioning today (Hicks and Peña 2003:411). However, the privatization of water rights under modern United States water laws and the emerging water markets have put great stress on acequias (Rivera 1998:171). As municipalities, large agribusinesses, recreation interests, and expanding industrial users have increased the demand for water in Colorado, some acequia communities have faced pressure to forgo their water management practices (Rodriguez 2006:1; Rivera 1998:171). When faced with daunting challenges to their water rights, the relatively poor communities often are unable to defend their interest (Rivera 1998:157). In addition, some younger members of acequia communities do not have the strong cultural ties to the land and are tempted by outside interests to sell their water rights or pursue alternate employment opportunities (Jacquez 2014). The Colorado Acequia Recognition Law, passed in 2009 and amended in 2013, addresses some of the factors that are undermining the effectiveness of acequias and gives needed recognition to these historically and culturally significant communities (Colorado Revised Statutes § 7-42-101.5 (2013) (amending Colo. Rev. Stat. § 7-42-101.5 (2009)). In light of the pressures facing acequia communities, I undertook research on the status of acequias in the San Luis Valley of Southern Colorado and the interaction between acequia water management practices in the Valley and current Colorado water law, including the Acequia Recognition Law. This study is conducted with the awareness that Colorado water law must address the needs and concerns of many different interests. With this understanding, my examination focuses on the viability of acequias in the San Luis Valley.