NRCS Irrigation Page 

The NRCS Irrigation Page provides information on a wide variety of irrigation topics including: Water management models, irrigation discussion groups, and a number of handbooks and manuals concerning irrigation systems.

ATTRA National Center for Appropriate Technologies

ATTRA provides a wide variety of Drought-Related material, including many of those areas previously mentioned here, including: Irrigation scheduling, system maintenance and evaluations, and crop selection/patterns