Headwaters News Forum: Water in the West
Topic - Water Conservation
Guest
Posted: Thu May 16, 2002 6:59 pm Subject: Water Conservation
Water conservation might solve one problem concerning in-stream flows but can cause problems when dealing with conjunctive management of surface and ground water resources. For example, in Idaho, we divert as much as 10 ac/ft of water for irrigation purposes. A person may think that conservation would help in-stream flows if farmers would conserve this water because the crop consumptive use is 3 acre/feet. Yet, 75% of this water goes into the Snake Plain aquifer or is evaporated into the atmosphere. If water conservation was forced on these users, it would affect other pumped beneficial uses of irrigation, municipal, industrial, or domestic on the Snake River plain 50 to 100 miles away. These uses do not have a replacement water supply that is practical or cost effective for those uses.
David Getches
Posted: Thu May 16, 2002 7:28 pm Subject: Water Conservation
To be sure, reducing the amount of water diverted from streams by farmers can create problems for users who have become dependent on pumping out the water that is not consumed by crops. Some water also seeps slowly back to the stream so that the season when it can be diverted by others downstream is longer.
But if the stream dries up, or is reduced to a trickle, fish die, so does riparian vegetation. Wildlife suffers as do humans who depend on fisheries or healthy ecosystems for their lifestyles or livelihoods. So to brush off water conservation because there are demands for using all of it up begs the question.
We have serious problems in the West precisely because of the attitude that any human use out of the stream is superior to any human or natural use that would keep in the stream. A major issue is how to ensure that we have some basic level of flows in our rivers - an issue that our predecessors did not deal with. Reducing diversions through modern irrigation techniques and other conservation measures is one way to do this.
Bill Loftus
Location: Moscow, Idaho
Posted: Thu May 16, 2002 7:52 pm Subject: Water conservation shows foresight
As David and the original guest both agree, conserving water by improving agricultural practices may well lead to problems for groundwater users elsewhere. But to avoid improving the efficient use of water would mean ignoring the droughts that are part of the facts of life on the Snake River Plain and nearly everywhere else.
In some years there may not be 10 acre feet to divert from the Snake River. In several recent years, three feet was a stretch. It is in the interest of all water users to see that irrigation water is used conservatively.
From there, the other issues can be addressed. If a city or an individual that relies on groundwater from the aquifer downstream runs into falling water levels as a result of more efficient irrigation practices, that can be addressed. There are no shortage of issues to address already. Instream flow is only one among many. The effects of low flows on water quality, wildlife, salmon and steelhead also need to be addressed. Climate shifts that may mean more rain and less snowpack are also an issue.
Although we can exert a lot of control over nature, particularly the flow of rivers, there are a lot of things we can´t control, such as climate.
The populations of Idaho and most western states continue to grow. The new residents´ priorities may not put as much value on agriculture as old timers. The newcomers will bring more pressure to bear on existing water supplies. To avoid finding ways to increase water conservation or the efficient use of water would only amplify the debate already taking place and that is sure to continue.
Guest
Posted: Thu May 16, 2002 8:05 pm
Just having a Focus West show on this evening has brought a positive rainfall event to Cheyenne. Water conservation is an important component of developing water to meet new demands or for protecting the environment, but conservation, by itself is not the solution to every problem. Some conservation can result in third party impacts to other water users and certainly have an affect upon the environment. As a result, the implementation of a conservation project must be carefully evaluated to first determine the actual savings of water and of the potential impacts and changes in timing of return flows and similar changes. Often, a storage or ground water recharge project working in conjunction with conservation can jointly be managed to maximize the benenfits of conservation.
Lynn Tominaga
Location: Idaho
Posted: Thu May 16, 2002 8:15 pm Subject: Conservation & Recharge
The use of water during times of drought and flood must be managed. During times of flood there isn't enough reservoir storage in any river system to be able to save it during times of drought. One piece of the puzzle is the use of artificial recharge of water into those aquifers that can store the water for use at another time. Another alternative to managing water is raising the present dams one or two feet which could increase the storage capacity of the reservoirs at relatively small costs in comparison to building new structures or impacting environmental concerns.
Howard Neibling
Posted: Thu May 16, 2002 8:19 pm Subject: Water conservation
Improved irrigation practices with higher application eficiencies are an important tool in reducing soil erosion, and achieving water quality improvement, better crop production, and more efficient use of labor. They can reduce "losses" such as runoff or deep percolation below the crop root zone. However, in a basin like the Snake Basin in Idaho, where surface and groundwater interact, water conservation will not put more water in the river in the long term. Conservation does allow reduced diversion which temporarily keeps more water in the river. However, reduced runoff will result in less return flow to the river and reduced seepage and deep percolation will reduce groundwater recharge. Seepage from leaking canals and excess irrigation is estimated to account for almost half the recharge to the Snake River Plain aquifer. Because groundwater adds significant flow to certain reaches of the river, less recharge will translate into less springflow back to the river. The net result is that after a period of time (5-10 years?) Flow in the river will be the same as it was before conservation. Conservation in this situation can change only the timing of peak flows or where in the river system the water enters the river (stays in the river at the diversion or enters later downstream in the springs). As a result, the only practical ways to keep more water in the river on a long-term basis are to reduce losses by crop water use (take land out of production), or by managed groundwater recharge of large springtime river flows.
Gens Johnson
Posted: Thu May 16, 2002 8:24 pm
I was surprised to read in the Atlas of the New West that alfalfa and potato crops are extremely thirsty. Rather than take land out of production (as Howard suggests in the technology thread, as the only meaningful long-term means to increase river flow), should irrigators be encouraged (aka crop subsidies) to change their crop to something that needs less water?
Guest
Posted: Thu May 16, 2002 8:33 pm Subject: water conservation
Water conservation is everyone's goal, but without "targets" for instream flows, all it does is allow more people to be greedy and divert and use more water. By itself conservation is a moral good, but it has to be coupled with public goals before it serves a broader purpose.
Lynn Tominaga
Location: Idaho
Posted: Thu May 16, 2002 8:48 pm Subject: Cropping Patterns
Cropping patterns are determined by price and supply demands. To have a subsidy for raising less intensive water use crops would not solve the problem. A farmer manages his soil and water to optiomize the use of those resources to make a profit. Cropping patterns are based on the rotational use or pattern which can best take care of the soil fertility and manages the resource.
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