Utah State University Extension
This fact sheet covers the basic components of a rain harvesting system, Utah's laws for rain harvesting, how to estimate the volume of water storage you will need, ideas for increasing water pressure in your system, as well as tips and insights for building a rain harvesting system.
Palmer, Matthew; Carter, Kohl; Brain, Roslynn; and Cromwell, Shannon, "Rainwater Harvesting for the Home and Farm" (2015). All Current Publications. Paper 2065.