Table O-25 Summary Results Low Impact, Expected Costs 100-YEAR NPV 1.63% DISCOUNT RATE ($2014), MILLIONS
Floodproofing Only Low Enhancement Only High Enhancement Only I-5 Project Alternative Variations I-5 Alternative + Airport Levee + Floodproofing + Low Enhancement I-5 Alternative + Airport Levee + Floodproofing + High Enhancement Upper Chehalis Storage Alternative Variations Storage + Airport Levee + Floodproofing + Low Enhancement Flood Retention RCC with CHTR Fish Passage Multipurpose RCC with CHTR Fish Passage Multipurpose RCC with Conventional Fishway Multipurpose Rockfill with Experimental Fishway Storage + Airport Levee + Floodproofing + High Enhancement Flood Retention RCC with CHTR Fish Passage Multipurpose RCC with CHTR Fish Passage Multipurpose RCC with Conventional Fishway Multipurpose Rockfill with Experimental Fishway Storage + I-5 Project Alternative Variations Storage + I-5 Alternative + Airport Levee + Floodproofing + Low Enhancement Flood Retention RCC with CHTR Fish Passage Multipurpose RCC with CHTR Fish Passage Multipurpose RCC with Conventional Fishway Multipurpose Rockfill with Experimental Fishway Storage + I-5 Alternative + Airport Levee + Floodproofing + High Enhancement Flood Retention RCC with CHTR Fish Passage Multipurpose RCC with CHTR Fish Passage Multipurpose RCC with Conventional Fishway Multipurpose Rockfill with Experimental Fishway
Chehalis Basin Strategy: Reducing Flood Damage and Enhancing Aquatic Species — Detailed Results
IMPACTS FLOOD ENVIRONMENTAL DAMAGE (USE VALUES REDUCTION ONLY) $86 $0 $0 $17 $0 $47
PROJECT IMPLEMENTATION COSTS $82 $95 $128
NET BENEFIT $4 -$78 -$81
BENEFIT /COST 1.1 0.2 0.4
$148 $148
$17 $47
$289 $322
-$124 -$127
0.6 0.6
$475 $475 $475 $475
$12 $11 $11 $11
$477 $608 $636 $819
$9 -$121 -$150 -$333
1.0 0.8 0.8 0.6
$475 $475 $475 $475
$43 $36 $36 $36
$511 $641 $669 $852
$7 -$130 -$158 -$342
1.0 0.8 0.8 0.6
$499 $499 $499 $499
$12 $11 $11 $11
$553 $683 $712 $895
-$42 -$173 -$201 -$384
0.9 0.7 0.7 0.6
$499 $499 $499 $499
$43 $36 $36 $36
$587 $717 $745 $928
-$44 -$182 -$210 -$393
0.9 0.7 0.7 0.6
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