Systems and methods for supporting a solar panel array are disclosed, with embodiments specifically directed to spanning bodies of water such as aqueducts, canals, or other waterways. Cable truss assemblies are used to support panel receivers and solar panels mounted over the panel receivers. The cable truss assemblies are supported on groups of columns or other vertically extending support members anchored in the ground. Cable anchor lines may supplement anchoring and support of the installed solar panel array. Embodiments of the system include various combinations of supporting cables making up the cable truss assemblies. A method is also provided for construction of the solar panel array. Lengthy and continuous spans of the solar panel array can be installed over waterways by use of the cable truss assemblies. The solar panel arrays produce power, and simultaneously reduce evaporation from the waterways, resulting in conservation of water.