The drought-shortened irrigation season just experienced by Treasure Valley irrigators has again focused attention on the question of additional water storage capacity on the Boise River system.
Should we build new water storage reservoirs, expand the capacity of existing reservoirs, or a combination of both without regard for its impact on the environment?
Or should we turn to some rigid type of silver-bullet restrictive water management process to more strictly control supplies and force demand to adhere to available resources?
As Boise River watermaster, I prefer the pragmatic, simple truths that fall between the two extremes of what is a deceivingly complicated issue.
It is crystal clear to me that increased water storage capacity is the only practical solution. Not because its the easiest or most convenient or politically correct, but because it is the only strategy that effectively meets the current and future demands we place on a finite natural resource over which we have no authority or control.
Strip away philosophical arguments and the issue is amazingly simple. Its all about snowpack. The amount of water available each summer is determined by the amount of snowpack we received the preceding winter. And we have absolutely zero control over how much snowpack we will receive.
Our area receives a scant 9 to 11 inches of annual precipitation. Without dams and reservoirs to store spring snowpack runoff, it is impossible to sustain our present lifestyle during the long, arid summers. Without reservoirs, a huge snowpack simply flows out of our valley in the form of devastating spring floods.
Without storage reservoirs, recreational values such as water skiing, boating and fishing cease to exist. Without storage water, the Boise River shrinks to a mere summer trickle, unable to support the tubing, fisheries habitat and summer lifestyle we cherish and promote. Storage water also provides water for Fish and Games winter minimum river stream flows.
Without storage water, our billion-dollar agricultural economy will collapse.
Life as we know it in the Treasure Valley exists only because we have the ability to maintain adequate river flows throughout the year, thanks to storage reservoirs.
As for water management, more than a century of Idaho law dictates exactly both the nature of use and the amount of water an individual farmer, a city, a homeowner or an entire irrigation district gets during the irrigation season. If overdiversion was a common practice, irrigation districts wouldnt need to end irrigation seasons early, cut back the yearly entitlement of water users or put locks on individual irrigation headgates.
Maybe we could save water by enclosing canals and ditches in pipes to eliminate evaporation or seepage into the ground. The result? An immediate and permanent decline in groundwater levels crucial to thousands of domestic wells across the Treasure Valley. Recharge from agricultural irrigation is what created and sustains the shallow aquifer into which those wells are drilled.
Finally, consider future needs. Planners estimate the Treasure Valley will be more than a million residents by 2050. We will need an additional 100,000 acre feet or more of water that must come from snowpack again, something over which we have zero control.
The Boise Basin annually produces 2 million acre feet of runoff water. Lucky Peak, Arrowrock and Anderson Ranch reservoirs can store 947,000 acre feet. That means a little more than 1 million acre feet of water simply leaves the area.
The answer is not philosophical; it is just plain common sense. We cannot make more water. We can only save more of what nature provides.
The choice is not storage or conservation. It is additional storage capacity for sure, and practical conservation where possible.
Rex Barrie is Boise River watermaster, Water District 63, which encompasses the entire Boise River Drainage.