Basic Thoughts

Some Basic Thoughts on Water Management

It has been said many times that agricultural water management, indeed any type of water management, is at a crossroads. I think it is more like a five level interchange with everyone wanting to go in different directions and each with a legitimate reason for going there..

The sad fact of the matter is that many important decisions regarding water resources were made in a different era. In that era there was little, if any, consideration given to protection of surface and ground water quality, the natural uses of water, or the freshwater fisheries.

Law and public opinion now want these issues addressed. However, we find that the modern environment, both natural and man-made, fostered by over 50-100 years of water development cannot be so blithely ignored as the natural environments were in the past. Thus, compromise is inevitable and required. Agriculture will give up water (compensated or not), cities will pay more and may even be forced to curtail growth, and as it must be admitted to by the most ardent conservationists, the original order has been forever altered.

All users, urban, industrial, environmental, and agricultural must acknowledge the validity of each other's claims, and their interrelationship. If there is no water for agriculture where is the food for a city? If there is no water for industry, where are the jobs for a city? If there is no water for the environment, where is the quality of life for the city (and the country)? And if there is no water for people, where is the city?

Irrigation is both an art and a science. Science has provided many concepts and methods for measurement of the various processes involved in irrigation. However, a farmer's knowledge of his/her field and crop, along with experience in interpreting this science will remain of utmost importance in achieving effective, efficient irrigations.

EFFECTIVE irrigations produce the desired crop response.

EFFICIENT irrigations make the best use of available water.

Irrigation efficiency does no good if it is not effective in producing a profitable crop. But increasing pressures on agriculture water supplies and legitimate concerns for water quality require that agriculture be as efficient as possible.

Effective, efficient irrigations are the result of knowing WHEN to irrigate, HOW MUCH to irrigate, and HOW to irrigate. (The Tutorials that are a part of this Site explain the concepts that help farmers know when, how, and how much to irrigate.)

WHEN to irrigate is an agronomic decision, based on how the crop is supposed to develop.

HOW MUCH to irrigate is normally the Soil Moisture Deficit in the effective root zone, but may be less depending on the specific crop/irrigation system/weather region mix.

HOW to irrigate is not just knowing how to set a siphon tube or hook up a sprinkler pump. Knowing HOW to irrigate is knowing how to achieve a high distribution uniformity and a high irrigation efficiency.

The "rubber meets the road" in the wise use of agricultural water resources when the farmer irrigates. As noted above the farmer's knowledge and motivation are all important. However, there must be nothing in the way to achieve the desired results. The farmer may know WHEN to irrigate, may know HOW MUCH to apply, may know HOW to apply it. However, if institutional constraints prevent him/her from exercising this knowledge, inefficiencies will result. Irrigation and Water Districts must be able to supply water when and where it is needed. Older Districts may need physical and management improvements. Resources must be available for these improvements.

"Enlightened" Water Management discussion