Table 2. Steady state groundwater-flow simulation water budgets for the three configurations used for the modified transient analysis, Mosier, Oregon, study area. 


[Recharge from precipitation and total pumping were prescribed model input, and the groundwater exchange with study area streams and the Columbia River were simulated output]


	Pre-development	Early time (circa 1970)	Late time (circa 2006)		Pre-development	Early time (circa 1970)	Late time (circa 2006)		Pre-development	Early time (circa 1970)	Late time (circa 2006)
	(Cubic feet per day)				(Acre-feet per year)				(Percent)
In
Recharge from precipitation1, 2	3,094,852.0	3,094,852.0	3,094,852.0		25,950	25,950	25,950		98.9	98.9	98.9
Leakage from streams to aquifers	33,515.7	33,004.8	34,096.8		281	277	286		1.1	1.1	1.1
Total	3,128,367.7	3,127,856.8	3,128,948.8		26,231	26,227	26,236		100	100	100
Out
Total leakage to streams (drains + streams)	1,329,031.6	1,310,651.3	1,148,866.4		11,144	10,990	9,633		42.5	41.9	36.7
Flow to Columbia River	1,799,365.3	1,788,569.1	1,868,357.3		15,088	14,997	15,666		57.5	57.2	59.7
Total pumping2	0.0	28,666.5	111,755.3		0	240	937		0.0	0.9	3.6
Total	3,128,396.9	3,127,886.9	3,128,979.0		26,232	26,227	26,236		100	100	100

¹ Estimated potential recharge from irrigation is significantly less than 1 percent of recharge from precipitation, and it occurs mostly in areas of strong upward hydraulic gradient.


² Non-consumptive rural residential pumping is assumed to return to the upper aquifer, the most likely source of this water, through septic systems. As a result, this water is not included in either Total Pumping or Recharge, having a zero net effect on the budget.

First posted March 1, 2012