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<br /> • - eon d~la Gr a~.adax~ eora'+iaa ora dtH~.ef from H1° sam,oMl aal>L tort n.-a4ae.•ro fy ogrlmltwel •
<br /> m,,,.,L.~ e.v e.,.e °n A D~°l~ mMtaleq °t hleraasle awQi+Pa~6^,nuwut r~ a lann~ dd• .
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<br /> for various project categories j Table 1 provides further Eeonorities of Scale
<br /> statistical details. including average median, minimum, and
<br /> maxirttum obseNed project torts itr each Category: Table 1 Sionificat7t fired costs are nssociattd with all but the most .
<br /> also shows the allocation of costs by construction stake . simple rtstora~ion projects and there can be si~77ificant quan= '
<br /> (pre-construction, eonsuucdon, and post-const,vetian~and city di,counts and labor cost s:~~°in_s ns the size of project.
<br /> by input category (labor, zquipment, material, and ocher). increase. Restocadon costs of lareec projects therzfore are•
<br /> Wetland restoration underralcen as'part of voluntary pro- lower, on a per-acre basis, than costs of smaller projects. In
<br /> • grams. in which agricultural lands are converted to wetland many tarts, hc~«'t?'er, the differences- in per-acre costs be=
<br /> under the auspices ofoovetnment ao ncics or nonprofit,
<br /> oups nveen large and small ~Ycdand restoration projects reflect got
<br /> are subsranrially less costly, on average, than niidgation pro- onl eels beinlCUnderral:enuBorh hcncomena,teconompes of
<br /> jeers-Evenafterdtepossiblyconfoaiadingeffectsofprojutsixe proj € p
<br /> • were stadsacally removed, average cost estimates for agpcul- scale and differences in project characteristics at different
<br /> total conversions in the secondary data were nearly two orders size restoration sitzs. contribute to cost differences in torts
<br /> of magnitude lowerthan costestimates foc~4etiand midgarion between large and small ~Letlaad restoration projects. Cost-•
<br /> projects (approximately $500 vs. $30.000 per acre).
<br /> COnuaSt,~fe[enceS`in w etland: type• had a surprisingly IguCC . EcenemlHS vl Scala
<br /> small effect on average restoration costs once site specific and. 1~
<br /> project-specific factors were accounted for.I?rojeet rusts varied ` ° ° ° ° °
<br /> more widely within wedand categotics than between wetland ° ~ ~ e
<br /> s
<br /> categories. Variations in project costs were so large within s° m
<br /> categories, in fact. that differencis in average project costs e ° 'o e ° °
<br /> between wetland types went not statistically distinguishable in Ira • ° 4 ° ° • .
<br /> tnostcases. Projectsizeand otheCSite-specific and project-ape- j °
<br /> cifie characteristics seem to have a lazoer and mote consistent = Tl
<br /> ' effect on project size than does wetland type. ~ ~
<br /> The estimated costs of wedand LeStoratton derived from n
<br /> our primary and secondary databases differed signifieaotly. ~ I ~ , •
<br /> Averaga wetland mid;ation costs (adjusted for pmjcct size) „ „ Iro
<br /> estimated from the secondary data (excluding; agricultural
<br /> conversion projects) were only 56 perczit[ of the average
<br /> costs estimated from the primary data..The secondary data,
<br /> based on historic wetland restoration -records, rcFlects the er-arce for r:lati~ el~~ small restoration projects (e.g., plant- .
<br /> costs actually incurred by pemtl[eesseeking mitigt:tionStrv- P
<br /> ices. xhe primary data, in contrast, were based on etiaineer- ings to rctluca shore{inr: erasion). for example, was often
<br />
<br /> . iao designs, cotLstructioa specifications, and attention to exceptionally high, while costs-per-acre foe large scale pro-
<br /> pre-construction research trod post-construction mainte_ jeers (t.g.. rtmnl'in; water control devices to flood large
<br /> agate ensuring high likelihoods of meeting! restoration tar- arms) wa. often e~trttrrely low.
<br /> gets.'Rre results of our data comparisons Suggests thar.~C~he .'the ptif:7a~- dare sugge.St that for each !0 petcCrrt increase in
<br /> ro ea Size, cost- r acre for non-agricultural projects declines
<br /> ;quality of wetland mitigation were to increase to tlr ol~vel ' b 35 troy t An rtna! sip of mitigation rojects in the larger
<br /> ~cepresented in our primary datfibase, a~..rage mitigation . sccat>v
<br /> n; dawbs~ t'eriled a re
<br /> markably similar decline
<br /> costs would be about 75 percent higher than those reported
<br /> for historical mitigation projects. coftri,rrte~lnaPe~e 8
<br /> • AMY/I V N ° 1994 5
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