Estimated iimpact of stormwater reuse for irrigation on average annual runoff reduction Estimated iimpact of stormwater reuse for irrigation on average annual runoff reduction

Estimated impact of stormwater reuse for irrigation on average annual runoff reduction. The table shows average annual runoff volumes (acre-feet) for 10 acre wastersheds as a function of soil group and percent imperviousness. The range of average annual volume reduction from reuse is shown in the last two columns.
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Hydrologic Soil Group (HSG)	Watershed Area (acre)	Watershed Imperviousness (%)	Average Annual Runoff Volume1 (acre-ft)	Range of Average Annual Runoff Volume Reduction2 (%)
A	10	10	2.3	6.0	98.3
	10	30	6.2	2.2	93.6
	10	50	10.2	1.4	86.2
	10	70	14.1	1.0	80.6
	10	90	18.1	0.8	76.7
B	10	10	3.2	4.3	91.7
	10	30	6.9	2.0	88.2
	10	50	10.7	1.3	83.3
	10	70	14.4	1.0	79.3
	10	90	18.2	0.8	76.4
C	10	10	3.9	3.5	87.6
	10	30	7.5	1.9	85.4
	10	50	11.1	1.3	81.8
	10	70	14.7	1.0	78.6
	10	90	18.3	0.8	76.2
D	10	10	4.7	2.9	84.6
	10	30	8.1	1.7	83.2
	10	50	11.5	1.2	80.5
	10	70	14.9	0.9	78.1
	10	90	18.4	0.8	76.0

^{1 - Based on 50-year P8 model run from January 1, 1955 through December 31, 2004 utilizing MSP climate data
2 - Assumes stormwater storage volume for reuse equivalent to the one week demand for irrigation water assuming an application rate of 1"/week over the application area & irrigation period from May through September}