Angling and recreation values of low-flow alleviation in rivers

Journal of Environmental Management (1999) 57, 71–83 Article No. jema.1999.0292, available online at http://www.idealibrary.com on

Angling and recreation values of low-flow alleviation in rivers K. G. Willis† and G. D. Garrod‡ This paper assesses the benefits to anglers and other recreation users of increasing flows along low-flow rivers to some environmentally acceptable flow regime (EAFR) from the current low-flow situation. Using different contingent valuation and stated preference techniques, the paper estimates the relative magnitude of the benefits of low-flow alleviation (LFA) to anglers compared with other recreation users. The benefits to anglers alone outweigh the costs of LFA in two of the seven rivers evaluated in south-west England. The value of informal recreation justifies LFA on another three rivers. Only where the costs of LFA are extremely high (in two of the seven rivers) do recreational benefits fail to exceed the costs of implementing an environmentally acceptable flow regime in these rivers. The inclusion of recreation values in decisions on water abstraction would result in greater environmental protection of rivers in Britain.  1999 Academic Press

Keywords: angling, rivers, low-flow alleviation, stated preference, contingent valuation.

Introduction Anglers, especially those in angling clubs and syndicates, are vociferous pressure groups when environmental conditions in rivers, whether from pollution, water quality, or lowflows, affect catch rates. Increased water abstraction from rivers and underlying aquifers in river catchment areas in England, has resulted in low-flows in some rivers during summer months, and even the complete drying up of some sections of the worst affected rivers. This has led to the virtual elimination of fishing on some sections of rivers during June, July, and August. Fishing in some 40 rivers in England and Wales are adversely affected by excessive abstractions of water, either from the river itself or from the underlying aquifer. Excessive water abstraction, resulting in low-flows, imposes external costs on anglers and other recreational users of rivers. Excessive abstraction arises through water companies choosing the least cost alternatives in water supply, to minimize costs to consumers; whilst ignoring the external costs imposed upon other existing users of rivers. The Environment Agency (EA), in England and Wales, is required to protect the environment against excessive abstractions, whilst at the 0301–4797/99/100071+13 $30.00/0

same time ensuring adequate water supplies are available for domestic and industrial use. The EA can protect the environment and alleviate low-flows in these rivers by revoking licences under the Water Resources Act 1963; relocating abstraction pumps to less sensitive points along the river; and engaging in engineering operations, to augment the flow along low-flow sections of the river during low-flow periods of the year, and by lining the river bed to reduce seepage. Whether it is economically efficient to alleviate low-flows depends on the benefits, which are mainly recreational, in relation to the costs of finding alternative supplies of water. Few studies have investigated the value to anglers and other recreation users of changing flows in rivers. Loss of recreational fishing benefits from hydro-electric energy production in Idaho has been estimated by Loomis et al. (1986); whilst Johnson and Adams (1988) estimated recreational fishing losses on the John Day River in Oregon due to water abstraction for irrigation purposes. However, both these studies were purely concerned with fishing values, ignoring the effect of flow changes on other recreation users; and both adopted an independent valuation and summation (IVS) measure. Hoehn and Randall (1989) have shown that IVS measures cannot be aggregated without biased results:

† Department of Town and Country Planning, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, UK ‡ Department of Agricultural Economics and Food Marketing, University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU, UK Received 15 October 1997; accepted 23 May 1998

 1999 Academic Press

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the IVS measure is only equal to compensating surplus (CS) if program elements are independent. As the number of low-flow alleviation (LFA) elements (from one to seven rivers) increase, substitution effects increase, and IVS will over-estimate CS. Over estimation of benefits of environmental improvements by IVS can be avoided by adopting a sequential (SEQ)1 or simultaneous (SIM)2 path approach. This study adopted a simultaneous approach: recreational users of all rivers in south-west England valued the LFA program as a whole, and then subdivided this value to individual elements (rivers) in the program.3 The objectives of this paper are to: (1) evaluate the benefits to anglers and other recreational users of increasing flows along low-flow rivers to some environmentally acceptable flow regime (EAFR) from the current low-flow situation; (2) estimate the relative magnitude of the benefits of LFA to anglers vis a` vis LFA benefits to other recreational users such as walkers; (3) assess whether benefits to anglers outweigh the costs of LFA in these rivers; or whether LFA can only be achieved by including benefits to other recreational users; 1

A sequential approach values program elements (e.g. the value of LFA in individual rivers) one river at a time from the initial ex ante position to the ex post program prescription, in a sequence of valuation changes, until all LFA elements are valued. 2 In this approach, respondents value the environmental program as a whole, and then subdivide this value to individual elements of the program using monetary apportionment, or through points and tokens. Since there is no natural ordering of the sequence of flow improvements in the different rivers, this approach is perhaps more logical in this situation. 3 In a study of the benefit of reductions in nutrient leaching into the North Sea from three Norwegian rivers [the Halden (H), Glomma (G), and Vansjo-Hobol (V)] Mangussen (1996) confirmed these effects predicted by theory, in terms of mean WTP per respondent: (1) (2) (3)

IVS (HGV) [independent valuation summation of the benefits of nutrient reductions in each river H, G, and V], was 1836 Norwegian Kronor (NOK). SEQ (HGV) [WTP for the sequence H, G, V] was NOK 1653 [although the difference between (1) and (2) results was not statistically significant]. SIM (HGV) [WTP for the simultaneous valuation of rivers H, G, and V, was NOK 1344, statistically significantly different from IVS at 10% level]. [The simultaneous valuation was derived by determining WTP for HGV in total, and then asking respondents to allocate this total WTP between each river].

(4) assess the extent to which, by internalizing external costs in the decision-making framework, the value of recreation could contribute to the environmental protection of rivers.

Study area The study comprised seven rivers in the south-west region of England (the counties of Cornwall, Devon, Dorset, Gloucestershire, Somerset, Wiltshire and Avon). These rivers were identified by the EA as those most seriously affected by low-flow in the south-west region due to the over abstraction of water. They were also the rivers for which the EA was proposing to undertake some remedial action, subject to the benefits of such action exceeding the costs. The seven rivers were: the Allen and the Piddle (to the north and west respectively of Bournemouth) in Dorset; the Avon (near Malmesbury) in north Wiltshire, and the Wylye (to the west of Salisbury) in south Wiltshire; and the Tavy, the Meavy (near Plymouth) and the Otter (near Exeter) all in south Devon. The Tavy is subject to low-flow from abstractions by a small hydro-electric power station, which releases water back into the river but at a lower point. The Meavy, which is a salmon spawning river, has water impounded by a reservoir. The natural flow rate of the Otter has been reduced by 20% due to abstractions; the river is unable to adequately dilute sewage effluent from its two main towns; and the river has to be re-stocked annually with game fish for angling. The Allen is one of the 20 worst affected low-flow rivers in the whole of England and Wales. Since the early 1970s, owners of riparian rights, angling syndicates and clubs, have complained about the effect of low-flow on game (brown trout and grayling) and coarse (roach and chub) fish stocks. There is augmentation of the river at three points to compensate for abstraction, but over the course of the year the augmentation is inadequate. The Avon near Malmesbury has game (brown trout) and coarse fish, and riverside walks. The landscape has historic interests, and the Avon flows through the grounds of several stately homes in the area. A total of

Angling and recreation values

56 million litres (ML) per day is licensed for abstraction in this section of the Avon; whilst 26 ML day−1 is available from additional boreholes to provide stream support to compensate for the abstraction (Atkins, 1994). Around Piddlehinton, 60% of the summer flow is lost through abstraction (Halcrow, 1995), mainly from the underlying aquifer, which lowers the water table and decreases the flow of springs which feed the river.

Environmental effects of low-flow Low-flows in rivers affect angling; the quality of other recreational activities; wildlife; and the general amenity and ‘natural’ appearance of the rivers. Low-flows in the rivers result in a restricted angling season: fishing is either not possible in June, July and August; or considerably reduced in terms of quality and catch rates. On the Avon, the catch during these 3 months is estimated to be only onetenth of that of the entire 7 month season. Low-flow affects spawning and the reproduction of fish stocks, necessitating restocking by riparian owners and angling clubs, with attendant financial costs. Commercial fish production is also affected. For example, since the 1980s, low-flows have reduced output from a fish farm on the Piddle by 6 tonnes per year or £10 800 per year by value (ERM, 1997). The low-flow regime also affects wildlife, and the ecological balance of plant communities changes. There is a change from perennial stream flora to winterbourne flora, with an increase in terrestrial plants in the stream channel. Some species of wildlife disappear. On the river Piddle the growth and distribution of ranunculus has been adversely affected by reduced summer flows, as has the associated populations of invertebrates, and fish which feed on this plant (ERM, 1997). The available habitat for the native crayfish has also been reduced. Low-flow on the Piddle has led to excessive growth of cress and other plants occluding the channel in the summer, and degrading the habitat. Increased siltation in the channel also occurs on low-flow rivers, reducing the areas of gravel in which salmon, trout, and other fish spawn.

Method The study uses a number of different economic expressed preference methods to estimate an individual’s welfare change from creating an EAFR in the rivers. The most parsimonious method was used for each recreational group. Thus for anglers who pay fees and are aware of prices different types and quality of angling opportunities, an openended (OE) contingent valuation (CV) question was used. For informal recreational users of rivers, who are not accustomed to paying a fee for walks and other activities along rivers, a discrete choice (DC) CV approach was adopted as recommended by the NOAA in the USA (Arrow et al., 1993). For an environmental gain, the benefit to anglers from LFA in the rivers, can be measured as the maximum monetary amount which can be taken from an individual to leave the individual at her original utility level. This is the compensating variation or WTP for the change in river flow. This compensating variation was estimated by CV (see Bateman and Willis, 1998; Garrod and Willis, 1999). Where the good in question is familiar (e.g. fishing quality), and an established market mechanism exists that elicits payments for improved provision (the case in angling), then an OE question provides a practical elicitation format. Payment mechanisms were adopted to elicit maximum willingnessto-pay (WTP) which were familiar to respondents and a reasonable way to pay for LFA to improve angling conditions. Anglers were asked whether they would be willing to pay more than they do currently to enjoy the improved fishing conditions that LFA would bring about in June, July, and August, the months affected by low-flows: syndicate members were asked about their WTP increased annual rod fees (the annual rod fee is equivalent to a year’s membership of the syndicate and carries a given set of fishing rights on a particular stretch of water); club members were asked their WTP higher annual membership fees (club membership typically entitles the individual to fish on a number of waters where the club holds fishing rights); and pay-per-day anglers were asked whether or not they would be willing to pay a higher price for their day permit on a given low-flow river and how many day permits they would

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purchase for that river at that price in a year. Differences in WTP and angling conditions are likely to be familiar to anglers; for example, they have the choice to join a higher priced syndicate in return for better quality fishing or accept a lower priced association with lower quality fishing. Club members and syndicate members were also asked how many additional days, if any, they would choose to fish on the river if flows were improved. Evaluating the benefits of an EAFR to informal recreational users of low-flow rivers was more problematic. For these users an EAFR is a ‘public good’. Moreover, EA policy in south-west England seeks to simultaneously alter three resource services (bathing water quality; river water quality; and flow levels in low-flow rivers), which households might view as either recreational substitutes or complements for one another. This creates particular problems for CV, since embedding effects typically arises in valuing multi-attribute environmental programs. Embedding arises when the same good (e.g. EAFR) is assigned a lower value if WTP for it is inferred from WTP for a more inclusive good, than when the particular good (EAFR) is evaluated on its own. For ‘public goods’ (i.e. excluding angling) embedding effects in this study were minimized in two ways: first by reminding respondents of other good causes that they might wish to support and asking how much more they would be willing to pay, compared with today, to support them. Second, the valuation of LFA was evaluated in a broader set of water quality goods, within a more holistic set of EA water quality objectives. The EA targets for improving (1) bathing-water quality and beach standards; (2) river water quality; and (3) flow levels in low-flow rivers, require that, within 5 years, all beaches meet European Union (EU) standards; all stretches of all rivers have acceptable flow standards, and only 750 miles of river fails to have good water quality. Including all these objectives in the evaluation, and valuing them simultaneously, meant that embedding effects were minimized and that all EA programme benefits could be aggregated directly without biased results. As the number of EA environmental programmes or policies increases, substitution effects increase; so any study to value an EAFR as an independent element, maintaining all other ele-

ments at their initial level, will over-estimate benefits when households have a preference for other environmental improvements (beach quality; and river water quality in other rivers), when these might also be implemented and required to be paid for out of the household’s budget. To avoid over-estimating the benefits of an EAFR to informal recreational users, the study adopted a simultaneous valuation approach, evaluating the derivative of the expenditure function between the environmental program ex ante and ex post, over all water quality improvements (beaches, river quality, and EAFR), in south-west England. Thus the value of an EAFR can be aggregated to the values for other water improvements; and the component valuation for the EAFR is unique and not subject to embedding (Hoehn and Randall, 1989). The benefits of an EAFR to informal recreational users was estimated by two different approaches in two separate surveys; although both methods adopted a simultaneous path framework. The first approach employed both a stated preference (SP) approach and a DC contingent valuation method (CVM); and surveyed a random sample of the general public in south-west England. The latter was required to estimate the number of visitors each river attracted. The second approach employed an iterative bidding format to elicit maximum WTP; and surveyed visitors to the Avon and Tavy; providing a cross-check on the benefits estimated through the SP method. In the SP method, respondents were asked to choose one of a set of descriptions of environmental quality improvements on the basis of their preferences for the attributes of the improvement and their WTP the prices attached to the descriptions. Adamowicz et al. (1996) suggested that presenting respondents with a set of choice experiments with a range of attribute levels and prices, allows more opportunity for respondents to express their true levels of preference; and because attribute levels and prices vary randomly across the set of choices there is less opportunity for respondents to act strategically. The SP questionnaire presented respondents with a series of four choice sets. Each set outlined three scenarios: (1) no increase in water charges with the current situation pertaining, i.e. nine beaches in south-west Eng-

Angling and recreation values

land failing to meet mandatory EU standards on cleanliness and water quality; 990 miles of river without good water quality; and 130 miles of river without acceptable flow levels; (2) two alternative choice sets, with varying increases in water charges for varying improvements in the number of beaches meeting EU standards, and miles of river with good water quality and acceptable flow levels. Respondents were asked select their preferred choice from amongst the three alternatives, on each of the four choice sets. Each choice set was chosen at random from an orthogonal set of 64 choice cards. In SP respondents are never fully aware of the purpose of comparison of choice sets in the survey. Because attribute levels and prices vary randomly across the set of choices there is less opportunity for respondents to act strategically (Adamowicz, 1996). Moreover, a set of choice experiments presents respondents with a range of attribute levels and prices giving them more opportunity to express their true levels of preference. In addition, these sort of questions are easier for respondents to answer because they imitate the consumer choice decisions which most of us make in our everyday lives. Other problems of applying CVM to non-priced open access recreation (e.g. strategic bias and freeriding) were also minimized by adopting a stated preference (SP) approach to estimate the value of an EAFR to other river users. In the iterative bidding (IB) format, ambivalence, motivated by uncertainty over the location of the individuals indifference curve, was addressed in the bidding game by adopting a qualitative scale to allow respondents to express how willing (intensity of preference), and more importantly how able, they were to pay a given amount (Ready et al., 1995). This increases thinking time, hence increasing accuracy; and allows the analyst to assess robustness of WTP amounts by following the consistency of their progression. Moreover, the qualitative choice scale allowed more accurate final WTP values to be determined, by permitting interpolation of value between the final ‘yes’ bid value and the first ‘no’ bid value on the IB scale. Thus, a well-designed IB game can be expected to produce robust and accurate estimates of maximum expected WTP. This maximum WTP value for all EA water improvement

initiatives was then simultaneously disaggregated by respondents between initiatives; and then for LFA spatially between the south-west and the remainder of Britain. The south-west allocation was then be disaggregated by respondents to specific rivers.

Surveys WTP surveys were undertaken of anglers. Each of the low-flow rivers served members of at least one of these angling types. A survey of 92 anglers belonging to different fishing clubs served by the seven low-flow rivers, and 37 members of fishing syndicates in the area, estimated the maximum anglers would be willing to pay for improved fishing conditions resulting from a more natural-flow regime in the low-flow river in which they fished or had the opportunity to fish. The value of an EAFR to other recreational users was derived from a stratified random sample survey of general public. This survey also permitted estimates to be derived of the number of households who used the specific low-flow rivers for recreational purposes; as well as to establish values for this use. The survey sampled 750 households in south-west England, and was undertaken by a professional market research firm with considerable experience in social research questionnaires. The random sample survey of the general public across south-west England was carried out between 22 July and 14 August 1996 in the homes of respondents.4 A computer-aided personal interview format was used, which allowed a random selection of stated preference choice cards and DC WTP amounts to be generated during the interview. A survey of informal recreational users along two of the low-flow rivers, the Avon and Tavy, was also undertaken as one of the validity checks on the SP approach. The survey of informal recreation users elicited WTP for environmental improvements using a combined closed-ended WTP and iterative

4

The sample was stratified to obtain a representative sample by age and socio-economic groups; and was carried out in 49 locations selected by the British Market Research Bureau, who conducted the survey, to ensure spatial coverage across the whole region.

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bidding question format. This presented respondents with a range of amounts from which they had to choose one; with iterative bidding combined with intensity of preference being used to assess the probability respondents would actual pay that amount, and to estimate maximum WTP. The simultaneous path approach was implemented by asking people to (1) allocate their maximum WTP bid amount across the four areas of EA policy [improvements to (a) beaches; (b) river water quality; (c) LFA; and (d) recreation, conservation, and fisheries management], using a (100) points system; (2) allocate their LFA amount between south-west England and the rest of Britain; and (3) within south-west England to allocate funds between the different low-flow rivers. A survey of visitors participating in informal recreation was undertaken along the River Tavy in Tavistock, Devon and beside the Upper Avon in Malmesbury, Wiltshire. A total of 721 interviews was undertaken of visitors, predominantly local people, plus tourists, walking along riverside paths, on a next person-to-pass basis to ensure a random survey. Interviews were undertaken between mid-July and late August 1996, at a variety of times (weekends, weekdays, within and outside vacation and normal working hours) to ensure the entire spectrum of summer users was included in the sample.

Results Benefits of LFA to anglers Eighty percent of club anglers said they would fish more days on low-flow rivers if flows were improved in summer months. However, about one-third of club anglers said that some of these extra days would be at the expense of fishing days at another site. Fifty-two percent of club anglers and 73% of syndicate members said they would be willing to pay additional fees if flows improved. Syndicate members were WTP £71·34 (std=£122·43) per year; and club anglers £25·28 (std=£66·11) or about 20% of mean club fees. Syndicate members willing to pay additional fees indicated

that they would fish an additional 28·8 (std= 24·3) days, almost double the number of days this subsample of anglers currently fish (15·8 days). The survey of anglers suggested that they would be willing to pay on average an additional £68·03 per year more for improved fishing brought about by LFA. These anglers would spend, on average, 17·9 more days fishing on these low-flow rivers than they do currently. This equates to a WTP per day of £3·80; a value which also incorporates any additional benefit anglers receive from improved flows on days they would have fished at current flow levels.

Benefits of LFA to the general public The randomization of choice experiment cards throughout the general public survey meant that the proportion of respondents selecting each of the three choices did not vary with the order in which the cards were presented. This indicated that respondent fatigue did not set in and that responses were consistent throughout the sequence of four choice experiments. However, over 40% of respondents selected Choice 1, the current situation at no extra charge, indicating that many respondents did not wish to pay more for EA sponsored water quality improvements. The choice experiment format allowed respondents to compare possible outcomes and costs and, in the light of the additional information provided by the choice card, select an outcome that offered them acceptable value for money in terms of environmental improvement. Following Adamowicz et al. (1996) the responses from choice experiments were used to estimate a discrete choice model of the probability Pr{i} of choosing a given alternative i, i.e.: Pr{i}=esVi/ResVj jeC where C is the choice set and s is a scale parameter. This assumes a Type I extreme value distribution for the error terms and that there is independence between different individuals and choices. Models were estimated using linear and quadratic functional

Angling and recreation values Table 1. Coefficients of variables in the choice model of river users Variable

Coefficient

t-Statistic

ASC-Choice2 (Alternative specific constant for choice 2)

−1·05140

−4·687

ASC-Choice3 (Alternative specific constant for choice 3)

−0·42326

−2·507

Charges (Increase in water charges)

−0·03091

−5·494

Beaches (Number of beaches below EC standards in South West)

−0·054824

−4·342

Pollute (Miles of polluted rivers in South West)

−0·00054849

−2·164

Low-flow (Miles of low-flow rivers in South West)

−0·0023484

−2·203

Choice2∗highinc (dummy variable: respondent household income >£26 000 per year)

0·91715

4·569

Choice3∗highinc

0·31984

1·710

Choice2∗U36 (dummy variable: respondent is aged 35 years or under)

0·49763

2·616

Choice3∗U36

0·40509

2·485

Choice2∗nonbeach (dummy variable: respondent did not visit any beaches in last year)

0·46121

2·072

Choice3∗nonbeach

−0·34156

−1·548

Choice2∗Somerset (dummy variable: respondent lives in county of Avon)

−1·1648

−3·166

Choice3∗Somerset

−0·33673

−1·424

Choice2∗healthy (dummy variable: respondent strongly agrees rivers will be health as today in 50 years time)

0·57502

3·381

Choice3∗healthy

0·37425

2·535

Choice2∗highextra (dummy variable: respondent willing to spend >£100 a year supporting other good causes)

1·0662

3·232

Choice3∗highextra

0·73610

2·288

Number of observations=1160; Log likelihood function=−1172·24; Log L: Constants only=−1243·64 Log L: No coefficients=−1247·39; Chi-squared[16]=142·80.

forms. Under the quadratic specification some attribute coefficients were not statistically significant, therefore the linear functional form was used for benefit estimation. Table 1 presents the results of the model. The alternative specific constants associated with selecting Choice 2 or Choice 3, were negative and statistically significant. This demonstrates that there is a negative utility associated with changing from the current situation (Choice 1) to one of the other alternatives—this is regardless of any utility

respondents may have for the attributes of these choices or any disutility arising from the increased water charges. A similar result was observed in Adamowicz et al. (1996) and was interpreted as a form of endowment effect. This term describes situations where respondents have a utility for remaining in the current situation rather than moving to an alternative. There could be a number of reasons for this effect. Respondents have been observed to have a psychological preference for the current situation above other options

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K. G. Willis and G. D. Garrod Table 2. Willingness-to-pay per household per year for marginal improvement in water quality Reduction

Extended specification

1 polluted beach 1 mile of polluted river 1 mile of low-flow river 1 mile of low-flow river: users (number of respondents=290) 1 mile of low-flow river: non-users (number of respondents=379)

£1·4310 £0·0190 £0·0580 £0·0760 ∗£0·0435∗

∗ This estimate is based on a coefficient value that was not statistically significant at any reasonable level.

that would seem to provide them with greater utility. Alternatively, respondents may mistrust the ability of the EA to make the improvements in water quality specified on the choice cards. Respondents may also have chosen the current situation as a form of protest. The pilot survey did not suggest, however, that the preference for the current situation occurred as a result of confusion over the choice experiment. The discrete choice probabilities are homogenous of degree zero in the parameters, implying that any attributes which are the same for all outcomes will drop out of the probability model. Thus, individual characteristics, such as income, cannot be treated as standard explanatory variables. Such individual specific variables can only be entered into the model interactively by using the equivalent of dummy variable interaction terms. Individual specific variables are incorporated as (n−1) alternative specific variables, where n is the number of choices in each choice card. The coefficients of the discrete choice model estimated incorporating a variety of alternative specific variables (two for each individual specific variable specified) are also reported in Table 1 where these coefficients are significant at the 10% level. The signs on the coefficient must be interpreted in terms of their effect on the estimated probability of choosing any given alternative. For example, respondents with high incomes have a greater probability of choosing environmental improvements over the base case, namely the current situation, compared to those on lower incomes. Respondents who have a preference for good causes (give >£100 per year) have a greater probability of choosing environmental improvements over the current situation compared to those who have a lower preference for good causes (spend <£100 per year supporting them).

Table 2 reports WTP for the marginal improvements in water quality defined by unit reductions in the number of polluted beaches and the lengths of river affected by low-flows and poor water quality. Respondents were willing to pay £1·43 to ensure that one additional beach meets EC standards on cleanliness; and £0·02 to clean up a mile of polluted river. Similarly respondents, who had visited one or more of the low-flow rivers, were willing to pay £0·076 per mile to improve flow conditions on these rivers. These estimates may be used for purposes of aggregation, although this relies on the presumption of constant marginal WTP for water quality improvement measures across south-west England. This may be the case for beaches but it is possible that, following substantial reductions in the length of rivers affected by low-flows and pollution, WTP for additional lengths to be improved could change. Economic theory would suggest that marginal WTP should decrease as the provision of the environmental good increases. On this basis it may be sensible to regard aggregate figures based on this assumption as being the equivalent of maximum welfare measures. Median welfare measures for non-marginal water quality improvements can also be estimated following the method of Hanemann (1984). This requires an examination of how utility levels change as a result of a specified improvement, and then calculating the magnitude of the associated increase in water charges (decrease in income) that would be required to make utility the same before and after the improvements. As Adamowicz et al. (1996) point out, the resulting welfare measures are multi-attribute versions of Hanemann’s median WTP estimate for contingent valuation. The model in Table 1 was used to calculate the discrete choice welfare estimate for visitors reported in Table 3, (i.e.

Angling and recreation values Table 3. Comparison of welfare estimates for EAFR for informal recreational users Method

Value for 130 km. reduction in the length of low-flow rivers

Stated preference: general public survey Discrete choice CVM: general public survey Iterative bidding CVM: informal visitors to Avon Tavy

6·16 10·78 9·29 5·34

(£s per household, 1996 prices).

Table 4. Aggregate maximum willingness to pay (WTP) for additional game fishing days brought about by low-flow alleviation Maximum Additional Game Fishing Days

Aggregate Maximum WTP for Additional Game Fishing Days

Net Aggregate WTP for Additional Game Fishing Days∗

Allen Upper Avon Meavy Otter Piddle Tavy† Wylye

5888 5704 1840 13 248 3860 6624 10 488

£22 374 £21 675 £6992 £50 342 £14 668 £25 171 £39 854

£17 489 £16 942 £5465 £39 350 £11 465 £19 684 £31 152

Totals

47 652

£181 076

£141 547

∗ Adjusted to reflect fact that some angling days (21·8%) may be transferred from other fishing sites. † Rough estimate only.

a reduction from 130 miles to 0 miles in the length of low-flow rivers).

Benefits of LFA to riverside visitors In the on-site recreation survey along the Avon and Tavy, 38% of visitors were willing to pay to fund EA improvements across the four policy areas: beaches; river water quality; LFA; and recreation, conservation, and fisheries management. Mean WTP was £28·22 per year, of which respondents wanted on average 22·5% (£6·35) to be targeted towards LFA. Some of respondents (42·4%) wished to spend, on average, 75·2% of their allocation in south-west England, with the remainder stating the EA should spend the funds as deemed necessary. Within the southwest, the preponderance of visitors wanted the greater proportion of their funds allocated to the river they were visiting. However, there were variations between rivers: whilst 54% of visitors to the Tavy wanted to target LFA

spending in the south-west, only 14% of these specifically wanted to target spending on the Tavy; only 34% visitors to the Avon wanted to target spending on LFA in the south-west, but of these 60% wanted the funds targeted on the Avon (£2·27 per household per year). Table 3 reveals the same general estimates of the benefits of an EAFR along the rivers to informal recreational users, irrespective of the elicitation method (SP, DC CVM, or IB); and irrespective of the sampling frame: users identified through a survey of the general public, or visitors sampled along the rivers themselves. This suggests that the results are robust and valid values for LFA in rivers in south-west England.

Aggregate benefits and costs of LFA Aggregate angling benefits can be estimated from the product of WTP for LFA and the

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K. G. Willis and G. D. Garrod Table 5. Estimated number of visitor and user households to low-flow rivers from the south-west England

Allen Upper Avon Meavy Otter Piddle Tavy Wylye One or more of the above (user households) None

Estimated number of visitor households∗

Percentage of south west households

Kilometers affected by low-flows

Aggregate benefits for user households

Aggregate benefits for visitor households

85 897 230 717 166 760 157 982 157 854 240 155 162 481 734 161

5·21 14·00 10·12 9·58 9·58 14·57 9·86 44·54

20 35 7 5 16 16 30

£697 453 £1 220 543 £244 109 £174 363 £557 960 £557 962 £1 046 179

£81 602 £383 567 £55 448 £37 521 £119 969 £182 518 £231 535

914 269

55·46

∗ Some households visit more than one low-flow river, so visitor household numbers cannot be aggregated to give user household numbers. These numbers are based upon a 2 year period.

additional carrying capacity for anglers at each river. The additional carrying capacity period covers 92 days in June to August, and represents the maximum possible increase in angling days due to LFA. The fishable length of each river was calculated, assuming two anglers (one on each bank) for every 550 m for game fishing and for every 18 m for coarse fishing, to derive the carrying capacity for anglers.5 Assuming each visit lasts 1 day, the difference between the carrying capacity and the current number of visits per day represents the maximum additional number of day visits for each river (see Table 4). The benefit of LFA to anglers was the maximum aggregate WTP for the 92 additional angling days that could result from LFA: calculated by multiplying the angling capacities by 92 days and then by £3·80 per day. The results of this calculation are given in Table 4. Some of these additional days would, of course, be taken at the expense of other angling days along different rivers. The survey of club anglers suggested that approximately 22% of the additional angling days at low-flow rivers would replace existing 5

The above figures are an approximation. On chalkstreams, syndicate anglers would expect to have between 600 and 800 m to fish, while on syndicate salmon/migratory trout streams, each ‘beat’ would comprise a length of over 800 m and would be expected to accommodate two rods (Lewis, 1996). Pressure on space for club anglers is more extreme and would reduce the length of fishing stretches: two clubs who have rights on the Allen and Wylye, respectively, have a maximum possible densities of one angler per 30 m and one angler per 62·5 m (Lewis, 1996).

angling days. This merely represents a transfer of benefits; hence the net additional benefits of LFA are given in Table 4, as well as the estimated gross benefits. However, all of these rivers might not be fished to capacity every day for 3 months; thus reducing estimated net additional aggregate WTP benefits below £141 500.6 Even so, this still represents a considerable potential benefit which, unlike the unpriced benefits accruing to casual visitors from the alleviation of low-flows in rivers, would be realised in terms of increased revenues to riparian owners. The general public survey permitted user households of low-flow rivers in south-west England to be identified, and allowed the number of visitor households to each of the seven low-flow rivers to be estimated.7 Table 5 records these user and visitor estimates; 6

There is evidence that people overstate their intended behaviour (see Willis and Powe, 1998) so all the extra fishing day benefits may not materialise. Also, increased numbers of anglers might lead to some localised congestion thereby reducing benefits. These factors are difficult to quantify and have therefore been excluded in subsequent analysis. 7 Users of low-flow rivers were defined as households who had visited any of the low-flow rivers over the preceding 2 years [this comprised less than 45% of households in south-west England]; whilst visitors were defined as households who had visited a specific low-flow river [the Tavy and the Avon were the rivers visited most often, attracting about a quarter of a million visitor households from the south west England over the preceding two years; the Meavy, Piddle and Otter all attracted in excess of 150 000 visitor households, while the River Allen was visited least with only 85 000 visitor households in the 2 year period].

Angling and recreation values Table 6. Net present value of aggregate benefits for improving low-flows across the entire length of all low flow rivers in south-west England (£000s, 1996 prices)

Allen Upper Avon Meavy Otter Piddle† Tavy† Wylye

Present value of costs

Present value of aggregate angling benefits∗

Present value of aggregate user benefits

Benefit/cost ratio for users

11 867 763 80 34 430 5471 unknown 224

291 282 91 656 191 328 519

11 624 20 342 4068 2906 9299 9299 17 436

0·980 26·661 50·850 0·084 1·700 — 77·839

∗ Capitalized from values in Table 4 at a 6% discount rate, the rate recommended by HM Treasury (1991) for environmental benefits. † User benefits are identical for these two rivers because both have the exactly same length affected by low flow: 16 km.

and also reports the length of each river affected by low-flows, which is important in estimating the aggregate benefits of LFA. User households were willing to pay £0·0475 per km. (£0·076 per mile) towards LFA in all low-flow rivers in south-west England. Total aggregate benefit to user households for LFA in each river is a function of the total number of user households, WTP per kilometre, and number of kilometres subject to low-flow along each river. The proportion of this amount contributed by visitors can be determined by multiplying the number of visitor households to each river by the WTP per kilometre and by the number of kilometres subject to low-flow along each river. The benefits accruing to visitors to each of the rivers are captured in the benefits

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accruing to the river user population; hence only the value to user households of LFA was included in the aggregate benefit estimates.

Policy implications Table 6 presents the results of the cost-benefit analysis of LFA in each of the rivers. The costs of LFA for each river represents the least financial cost solution8 to implementing an EAFR. The present values in Table 6 reveal that additional angling benefits from an EAFR would only justify the costs of LFA on the Meavy and Wylye, the rivers where the costs of LFA are extremely low. However, where

For example, for the Upper Piddle, the Environment Agency identified four alternative solutions: (1) total cessation of abstraction and (a) re-supplying the area from the south [present value (PV) £9 million] (b) resupplying the area from the north [PV=£3·6 million]. (2) reducing abstraction rate to 1·5 Ml day−1 (million litres per day) when the flow in any of the three villages reaches the trigger (target) flow of 2, 3, and 2 Ml day−1 at Alton Pancras, Piddletrenthide, and Piddlehinton respectively; otherwise retain abstraction at a maximum of 4·5 Ml day−1 when flow allows [PV £1·8 million]. (3) maintain abstraction from borehole at Alton Pancras at a maximum of 4·5 Ml day−1. Augment flow by up to 2 Ml day−1 from new borehole at White Lackington subject to a trigger flow at Piddlehinton of 2 Ml day−1 [PV £90 000]. (4) maintain abstraction from borehole at Alton Pancras at a maximum of 4·5 Ml day−1. New borehole at White Lackington would supply up to 3 Ml day−1 augmentation at Alton Pancras when the flow in any of the three villages reaches the trigger flows [PV £901 000]. Engineering solutions were similarly identified and costed on the Devils Brook, a tributary of the Piddle; and along the Middle Piddle. The least cost combination of the 11 LFA options currently considered by the Environment Agency along the three sections of the Piddle (Upper Piddle, Devils Brook, and Middle Piddle) were combined to produce the least cost option over all sections of the river. Similar calculations were undertaken for all the alternative engineering solution options for LFA along the Allen, Upper Avon, Meavy, Otter, and Wylye. Low-flow problems on the Tavy are caused by abstractions for hydro-electric power rather than public water supply. The granite bedrock means there is no underlying aquifer from which to augment river flow. LFA solutions on the Tavy will only become available once South West Water has decided upon its strategy for the generation of hydro-power on the Tavy after the year 2000 and the attainment of 1500 megawatts of electricity generation from non-fossil fuels in the UK as a whole, under the Non Fossil Fuel Obligation (NFFO). These are all financial costs of project installation and maintenance. In unregulated and unsubsidized capital markets in the UK it is assumed that financial costs equal opportunity costs (see HM Treasury, 1991).

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capital costs of LFA are higher, but not excessive, e.g. on the Avon, and Piddle, then LFA is economically feasible and justifiable if the benefits to informal recreational users of these rivers are included in the benefit–cost analysis. Indeed, LFA is almost justified (and would be so within the margin of error in the data) on the Allen; here the B/C ratio is 0·980. Clearly, when recreational user benefits are included, some B/C ratios for LFA are extremely high (e.g. for the Avon, Meavy, and Wylye). These results suggest that if angling and informal recreational benefits had been formally monetarized and included in the benefit–cost calculation for water abstraction from these rivers, abstraction licences leading to such excessive abstraction would not have been granted. The loss of recreational benefits from water abstraction is currently overlooked or ignored by water companies in their desire to obtain water at minimum cost. The formal inclusion of the loss of angling benefits, which excessive abstraction entails, in the B/C calculation would have ensured the continuation of an EAFR on two of the seven most severely affected lowflow rivers in south-west England. Indeed, the gain in angling benefits, in relation to the costs of alternative water supplies to those of the Meavy and the Wylye, indicates that an EAFR should be restored immediately on these two rivers. The inclusion of informal recreational benefits justifies LFA on further rivers, namely the Allen, Avon, and Piddle. Only on the Otter and the Tavy are the recreational benefits from an EAFR less than the costs of LFA, mainly because no low or reasonable cost solutions exist. The engineering solutions for LFA on these two rivers are extremely costly. There are no feasible alternative water supplies along the Otter; and the complication of hydro-electric power and the Non Fossil Fuel Obligation on the Tavy, preclude low cost LFA solutions on these two rivers at present; although LFA might become viable at some point in the future.

Conclusions Water companies abstract water from rivers and underlying aquifers reducing river flow

to such an extent that some sections of rivers dry up completely during summer months. This adversely affects the recreational use of rivers, especially for anglers and other users such as walkers. This study of seven severely affected lowflow rivers in south-west England, has shown that the benefits to anglers and other general recreational users, of increasing river flows to an EAFR from current low-flow levels, exceeds costs. Only in a small number of cases where costs are excessive, because there are no feasible engineering solutions to the problem of LFA, is it justifiable to permit water companies to continue to over-abstract water from these rivers. However, the study shows that whether an EAFR is achievable mainly depends upon costs rather than benefits to anglers and recreational users of different rivers. The benefits to anglers and other recreational users, of an EAFR, vary between rivers; but the costs of LFA vary even more, depending upon the amount of engineering work required to create an EAFR and to replace the water from elsewhere. The results of this research suggest that the recreational value to anglers alone of an EAFR justify the implementation of LFA only in a minority of rivers. The inclusion of other recreational benefits suggests a majority of rivers should be protected from excessive abstractions of water which reduce river flow below an EAFR. The impact on recreation of some environmental resource changes is significant. The important and significance of role of the ‘public good’ nature of recreation in river catchment area management needs to be accorded greater recognition by the EA. The more formal inclusion of recreational values in the decision-making process over water abstraction by the EA, would ensure a greater degree of protection for rivers than currently occurs. Blamey (1998) argues that the highly symbolic and emotional nature of many environmental issues can result in valueexpressive considerations dominating some CVM responses at the expense of desired outcome-appraisal economic trade-offs. However, at least three of the four valuation methods used in this study appear applicable to determining these trade-offs for anglers and informal recreation users of rivers. OE

Angling and recreation values

CV can be effectively used to measure welfare increases to anglers who already pay fees for fishing rights. SP can provide robust measures of informal recreational values for different elements in a multi-attribute programme; whilst IB provides more robust estimates of individual elements than single bounded DC. These findings are consistent with the use of SP in Australia by Morrison et al. (1997) and (1998) to value other water use trade-offs in the Macquarie and Gwydir Valleys in New South Wales.

Acknowledgement The research was funded by the Environment Agency (EA) (South West Region). We thank Rob Westcott of the EA for providing information on the costs of various engineering solutions to LFA in the rivers. The views expressed are in this article are those of the authors.

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