Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 13, 2009
Publication Date: N/A
Technical Abstract: Although water harvesting techniques have been used effectively in irrigated agriculture and domestic water supplies, there seems to have been little continued exploitation of the same techniques in arid and semiarid rangeland restoration. A review of the history of rangeland water harvesting allows identification of the methods that have been useful in the past and which would be likely effective in the future. It seems that relatively simple water harvesting approaches work best on rangelands, particularly water ponding dikes to stimulate vegetation growth, and possibly the use of larger-scale water spreaders. The complexity of larger scale applications, however, may lead to problems in operational use. Experience from rangeland water harvesting at the Jornada Experimental Range in the south central New Mexico and other locations in the Southwest indicates that the approach is a long-term solution that produces significant vegetation growth, generally 10-15 years after installation because of the sporadic and spatially distributed nature of the summer monsoon rainfall. Additionally, the use of water ponding dikes seems to most reliably produce an “island” of enhanced soil moisture and increased habitat cover and forage. Water ponding dikes are easy and relatively inexpensive to construct and produce a pattern of vegetation similar to naturally occurring banded vegetation. Even very shallow dikes (7.5cm) are shown to produce ponds and a significant vegetation response. Research needs to be done to determine if the bands of vegetation behind the dikes will function like natural banded vegetation and expand to larger areas. Climate change continues to impact our water supplies, and the historical techniques of water harvesting that have been successfully used for over 9,000 years are a viable rangeland water conservation alternative now and in the future.