95 



THE FAILURE OF TRADITIONAL WATERSHED RESTORATION APPROACHES 



A recent Amencan Fishenes S«)Ciety report tuund that "In the past 10 years, many millions of dollars have been spent on 

 stream habitat management m Western North Amenca. We find little dcwnmenled evidence of mcreased abundance of 

 salmonids associated with these massive expenditures." 



Traditional approaches to stream habitat and ecosystem restoration can be characterized as "band-aid" approaches that 

 have several distmguishmg features. First, the identification and diagnosis of habitat problems tends U) be fiKUsed on 

 fmdmg patches of habitat that are amenable to predetemuned. generic lechmques. For example, many past and current 

 programs rely heavily on mstallation of log weirs tt) construct pools m streams. Planiung for these projects generally 

 focuses on identifymg reaches of stream that do not meet water temperature standards or with gradient and bank 

 strucMre suited physically to the mstallauon of such devices, and that happen to be accessible to the heavy equipment 

 needed to do the work. There is httle consideration whether the fish community, or the watershed as a whole, are suited 

 to the kmds of changes of habitat these structures are mtended to mduce. It is commonly assumed thai all fish benefit 

 equally from the plunge pool sequences created by such devices, and that the construction of weir pools will compensate 

 for all of the diverse changes m the ecosystem caused by human disturbance. 



Some evaluations of these projects indicate serious shortcommgs. For example, where log weirs and other artificial 

 strucmres achieve their physical objectives, their effects on native fish can be insigmficant, or even negative. In other 

 cases, they may stay m place, but have unmlended and damagmg physical side effects, such as severe bank erosion or 

 blockages to juvenile fish migration. Finally, m many cases, such structures suffer a high mcidence of outnght physical 

 failure. The results of numerous studies suggest that the effects of such projects are mconsistent and difficult to predict. 

 Conditions m the watershed as a whole appear to be more unportant than structure design m detemiimng whether 

 structures will function or fail. Failure rates are especially high m severely damaged watersheds or stream reaches 

 where disturbances are ongomg. Furthermore, m some watersheds fish populations are so widely depleted by extensive 

 habitat degradabon and other factors that few or no fish are available to colonize artificially created habitats. Finally, 

 the vast majonty of streams are not accessible to heavy equipment or are otherwise unsuited to structural modification. 

 Put simply, traditional lechmques fail to address the root biological and physical causes of habitat deterioration and 

 population decUne, and often aggravate, comphcate. or add to existmg problems. 



Pnonties for traditional "band-aid" restoration approaches are typically deteimmed by identifying the worst-degraded or 

 ughest-lookmg sites, and spendmg all available resources treatmg these areas with generic and largely cosmetic strucUral 

 techmques to "bnng them up to standards." Once the desired improvements have been made, further habitat-disturbmg 

 activities m the watershed can be allowed to proceed. 



The resuh of the "band-aid" strategy is predictable: disturbances are maximally dispersed across the landscape, and 

 virtually all sites across the landscape are homogeneously degraded. The worst sites may be partially "fixed," but 

 meanwhile disturbance-sensitive species have likely been lost through the entire stream system. As road networks and 

 loggmg imits are dispersed across the landscape, virtually every tributary and stream reach becomes vukierable to 

 management- accelerated disturbance from sedunentation and other effects when the next large storm strikes. Because no 

 effort IS made to identify and protect key watershed refugia, the most productive and diverse habitats are subject to 

 continued disturbance, while the most severely degraded areas (inherently the least amenable to structural unprovemeni, 

 and therefore the most hkely sites of project failure) receive all the restoration resources. In other words, this strategy is 

 a recipe for the degradation of the remammg healthier watersheds and other kmds of secure ecological refugia- leadmg 

 predictably to the cumulative extirpation of formerly abundant, but sensitive species over large areas. 



Past and present approaches to the management of watersheds and nverine-npanan have not only allowed the present 

 crisis to develop, they have mdeed exacerbated it. For example, the mtense fisheries generated dunng periods when 

 hatchery stocks are productive have often driven wild stocks mto declme and local extmction. Perhaps worse, rehance 



