investing in sustainable catchments.pdf
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Science of the Total Environment 324 (2004) 124
0048-9697/04/$ - see front matter 2003 Elsevier B.V. All rights reserved.doi:10.1016/j.scitotenv.2003.10.019
Investing in sustainable catchmentsMark Everard*
Visiting Research Fellow, Faculty of Applied Sciences, University of the West of England, Frenchay Campus, Coldharbour Lane,Bristol BS16 1QY, UK
Catchments constitute logical units for management of the water cycle. Patterns of development uninformed bysustainability concerns have degraded catchment integrity and associated ecosystem functions, imposing largelyunquantified costs. Ecosystem functions are central to sustainable social and economic progress; their protection orrestoration may be the only sustainable form of investment in catchments. Despite growing use of catchment functionsin some policy areas, a shortfall in awareness and pragmatic tools limits progress with policies and practical tools tosupport sustainable development in catchments, perpetuating damaging practices. This paper reviews methods ofeconomic valuation of riverine systems. Valuation of ecosystem functions is revealed as particularly pertinent tosustainable development, as an indicator of the benefits of ecological processes to social and economic progress. Arange of practical projects, targeted at restoration of riverine habitat in the UK with the intent of improving both riverecology and the social and economic advantages that flow from it, is also reviewed. Emerging principles and themesare discussed in terms of their potential contribution to policies and practices that promote sustainability. Review ofthese projects highlights the importance of planning at adequately broad scalesspatial, temporal and disciplinaryto identify integrated solutions, and to maximise community buy-in and total benefits. In several cases, economicanalyses demonstrate strongly positive benefitcost ratios stemming from habitat improvement. However, majorreform of regulatory and economic instruments is needed to promote sustainable catchment development, sinceprevalent perverse incentives continue to degrade ecosystem functions. Measures to recognise and reward ecosystemservice as legitimate outputs from agricultural land use constitute a particular priority. There is a need simultaneouslyto address both big picture structural adjustments and locally-appropriate solutions, from which clear local benefitsflow. Pragmatic measures that contribute to systemic outcomes must also be attractive to local decision-makers andland managers, and yield benefits that ensure they are sustained once intervention ceases. Cost need not be a barrier,as current environmentally-damaging subsidies may instead be redirected towards sensitive land use andyor measuresto protect biodiversity and ecosystem functioning, particularly where targeted upon habitat of disproportionateimportance to functioning of catchments as whole systems. Internalisation of the costs of damage to ecosystemfunctioning will promote valuation of the natural capital of catchments as a primary resource for social and economicprogress. 2003 Elsevier B.V. All rights reserved.
Keywords: Catchments; Ecosystem functions; Sustainable development; Land use; Partnership; Benefitcost assessment
*Tel.: q44-1249-721208.E-mail address: firstname.lastname@example.org (M. Everard).
2 M. Everard / Science of the Total Environment 324 (2004) 124
Sustainable development integrates social andeconomic progress with the ecological processesupon which human health, economic activities andquality of life depend (World Commission onEnvironment and Development, 1987). The watercycle provides ecosystem functionshydrological,ecological and physico-chemicalof centralimportance to sustainability, including provision ofeconomic, recreational, aesthetic, educational andspiritual opportunity. Catchment systems constitutelogical management units, throughout which alldecisions and actions have interdependent ecolog-ical, social and economic implications (Golley,1993; Newson, 1994; Zalewski et al., 1997; Ever-ard, 1997a; Calder, 1999; Powell, 2000). Catch-ment integrity maximises ecosystem functioning,carrying capacity and resilience (Everard andPowell, 2002).Biodiversity is perhaps the most important indi-
cator of overall ecosystem health and possibly offunction. The literature on the linkage betweenbiological diversity and ecosystem functioning isequivocal. On the basis of an extensive review ofobservational, theoretical and experimental studies,Schwartz et al. (2000) concluded that there wasonly a weak relationship between species diversityand ecosystem stability, and suggested that thiswas due to dominance patterns in natural andexperimental communities with the contribution ofrare species being practically non-existent. How-ever, this conclusion is based on studies addressingsingle or few functions, and on experimental con-ditions that did not necessarily reflect the variabil-ity of environmental conditions to whichecosystems have to adapt. In another review, Til-man (1997) argues that greater species diversitymaximises the potential for resource exploitationwhich, whilst potentially not maximising thepotential of individual ecosystem functions (suchas productivity in the case of agricultural and othermonocultures), maximises the breadth of functionsperformed by ecosystems, their inherent stabilityand resilience to disturbance, and sustainability.The beneficial functional processes of diverse bio-logical systems, argues Tilman, do not arisethrough direct and simple relationships but are
manifestations of the complex interactions withinadaptable and complex systems. What is quiteclear is that there is a positive relationship betweenbiodiversity and ecological functions that is ofindeterminate, or at least undetermined, strength.Cook and Shelton (2000) advance the idea ofbiodiversity and ecosystem function protection asa form of ecological insurance.Industrialised society is founded upon historic
assumptions that generally externalise the benefitsgained from catchment functions. Unsustainabledecisions relating to river systems commonly arisefrom a perspective shaped purely by human utility(Gardiner and Perala-Gardiner, 2000; Boon et al.,2000), including resource, land use and planningdecisions that ignore the implications for water inthe landscape (Newson, 1994; Costanza et al.,1997; Everard, 1997a,b; Calder, 1999; Mance etal., 2002; Everard and Powell, 2002). Poor man-agement decisions that degrade catchment func-tions can give rise to substantial social harm,economic costs and unsustainability (Dugan, 1990;Doppett et al., 1993; Boon et al., 2000; Brown,2001). In particular, decisions taken to manageproblems on a parochial, short-term or singleissue basis may overlook catchment-scale pro-cesses, generating adverse effects across the sys-tem as a whole. Historic, locally-focusedapproaches to flood defence provide pertinentexamples of all three issues of scale (space, timeand discipline), often diminishing flood storagecapacity, exacerbating flood risk downstream,adversely affecting longer-term geomorphologicalprocesses, and with ramifications for water quality,fisheries, recreation, or ecological health.Restoration of ecosystem functions to rebuild
carrying capacity may be the only sustainableform of investment in catchments (Everard, 1997a;Daily et al., 2000; Everard and Powell, 2002). Thetheoretical arguments are persuasive, but practicaldemonstration is necessary to help policy-makersand managers make informed, long-term decisions.A growing number of studies on aspects of riverbasin conservation or restoration, many not subjectto peer review or published for a wide readership,demonstrate principles and conclusions of value todecision-makers. This paper discusses methods andattitudes to valuation of rivers and other environ-
3M. Everard / Science of the Total Environment 324 (2004) 124
Fig. 1. Indicative location map of UK schemes, rivers and sitesnoted in this paper, numbered in order referenced. (1) TheHumber Estuary, (2) the River Wensum, (3) the River Tamar,(4) the Rivers Taw-Torridge, (5) Cornwall (ten rivers consti-tute the Cornwall Rivers Project), (6) the River Dart, (7) theRiver Tale, (8) the River Eden, (9) the River Tweed, (10)Darlington (River Skerne site), (11) Coleshill (River Colesite), (12) High Hullockhowe Farm, (13) River Cole (Bir-mingham), (14) Tyneside, (15) Wearside, (16) Stoke-on-Trent,(17) the River Medway, (18) Pembrokeshire, (19) the RiversLune and Wyre, (20) the River Ribble, (21) the HampshireAvon (Wessex Salmon and Rivers Trust), (22) Leeds (the Riv-er Aire), (23) the Mersey Basin, (24) Malmesbury (the rivervalley of the Bristol Avon) and (25) the River Foss.
mental resources, and introduces a selection ofpractical case studies from the UK. The principalpurposes and conclusions of some additional river-based initiatives are also outlined where theyprovide insights into the costs and benefits of riverfunctions, together with the findings of some peer-reviewed studies set in a broader sustainabilitycontext. The emerging principles and themes arediscussed in terms of their contribution to policiesand practices that promote sustainability.
2. Assessment of costs and benefits in rivercatchments
2.1. Valuation of rivers
Traditional economic appraisal methods appliedto rivers by statutory bodies to justify and prioritisecapital expenditure programmes (for example USEnvironmental Protection Agency, 1983; HerMajestys Treasury, 1991; Department of the Envi-ronment, 1991; Foundation for Water Research,1996) have tended to focus predominantly uponlocal human uses (drinking and irrigation waterquality, angling, informal recreation, etc.). Theseutilitarian evaluations largely exclude or margin-alise intangible values yet, notwithstanding thisnarrow spati