Abstract
The River Itchen is a classic chalk river arising from the chalk aquifer of the Hampshire Downs in central southern England. It is world famous for its fly fishing for trout and Atlantic salmon and was where the techniques of dry fly fishing were first developed in the early 20th century. The river has been used for centuries as a source of power, to irrigate flood plain water meadows and as a source of drinking water. These various uses have had a range of effects on the river and its associated wetlands but despite these many changes it retains a rich biodiversity. This case considers predicted future impacts of abstraction (extraction) for public water supply. This could be an example of ‘imminent threat’ as defined in the Environmental Liability Directive (Article 2—‘sufficient likelihood that environmental damage will occur in the near future’). The removal of water from the river results in reduced water levels and most importantly, reduced flow velocity. This causes a range of effects on the river including increased temperature, reduced oxygen concentration and increased concentration of plant nutrients, particularly phosphate, and other contaminants. Previous investigations have shown that in naturally dry years water abstraction has the potential to cause damage to the populations of Atlantic salmon and the floating Ranunculus habitat of the river. This case study uses habitat and resource equivalency analyses to estimate the damage and select compensatory remediation. The economic value of Atlantic salmon is also presented.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
Low-flow events occur where flow drops below the long-term Q95 flow (the flow that is exceeded 95% of the time; measured in megalitres/day, or Ml/d). The Q95 is established by creating a flow-frequency curve for the river. Q95 is the flow that is exceeded 95% of the time.
- 2.
Standardised flow units were established for the river by relating recorded flows to the long-term mean summer Q95 flow. Flows above the long-term mean scored >1 and flows below the long-term mean summer flow scored <1.
- 3.
- 4.
Radford et al. (1991) note that almost all the inland fisheries in England are private properties and hence can be bought and sold on the market.
- 5.
References
Atkins. (2006). River Itchen SAC review of consents, water resources stage 4 project, site action plan: Appendix B—Development of a stage 4 target flow regime, Unpublished report to the Environment Agency.
Baglinièrea, J.-L., Marchandb, F., & Vauclin, (2005). Inter-annual changes in recruitment of the Atlantic salmon (Salmo salar) population in the River Oir (Lower Normandy, France): Relationships with spawners and in-stream habitat. ICES Journal of Marine Science: Journal du Conseil, 62(4), 695–707.
Environment Agency. (2004). The State of England’s Chalk Rivers. A report by the UK Biodiversity Action Plan Steering Group for Chalk Rivers, Environment Agency and English Nature.
Environment Agency. (2006). Salmon stock assessment report: Annual assessment of salmon stocks and fisheries in England and Wales, Bristol.
Environment Agency. (2007). Results of electro-fishing surveys, Langford Lakes, 2003–2007, River Wyle, Avon Catchment, Unpublished data provided by the Environment Agency.
Environment Agency and CEFAS. (2006). Annual assessment of salmon stocks and fisheries in England and Wales 2006. Report by Environment Agency, Centre for Environment, Fisheries & Aquaculture Science.
European Commission. (2007). Guidance document on Article 6(4) of the ‘Habitats Directive’ 92/43/EEC, Brussels.
Exley, K. P. (2003). The River Itchen macrophyte community, Unpublished report to the River Itchen Sustainability Study, November.
Exley, K. P. (2004). Macroinvertebrate habitat and community status of the River Itchen, Unpublished report to the River Itchen Sustainability Study.
Exley, K. P. (2006). River Itchen macroinvertebrate community relationship to river flow changes, Unpublished Report, Environment Agency.
Extence, C. A. (1981). The effect of drought on benthic invertebrate communities in a lowland river. Hydrobiol, 83, 217–224.
Extence, C. A., Balbi, D. M., & Chadd, R. P. (1999). River flow indexing using British benthic macroinvertebrates: A framework for setting hydroecological objectives. Regulated Rivers: Research & Management, 15, 543–574.
Fewings, G. A. (2004). Estimation of the effect of river discharge management on the passage of Atlantic salmon (Salmo salar L.) through the lower reaches of the River Itchen in Hampshire, Unpublished report to the River Itchen Sustainability Study.
Holmes, N. (2003). Concept designs for River Rehabilitation and enhanced Salmon Migration above Woodmill Pool, Unpublished report to the River Itchen Sustainability Study.
Nijboer, R. C., Verdonschot, P. F. M., & Van Der Werf, D. C. (2005). The use of indicator taxa as representatives of communities in bioassessment. Freshwater Biology, 50, 1427–1440.
Radford, A. F., Hatcher, A., & Whitmarsh, D. (1991). An economic evaluation of salmon fisheries in Great Britain, a Research Report to the Ministry of Agriculture Fisheries and Food, Research Report 16, Centre for the Economics and Management of Aquatic Resources, University of Portsmouth.
Radford, A. F., Riddington, G., & Tingley, D. (2001). Economic evaluation of inland fisheries: Economic evaluation of fishing rights, R&D Technical Report/Project Record W2-039/TR/1 (Module A), Report to the Environmental Agency for England and Wales, Bristol.
Riley, W. D., Mason, C., Rowlatt, S. M., Maxwell, D., Campbell, S., & Hull, S., (1998). The efficacy of River channel modification in maintaining improvements in salmonid spawning gravels following cleaning: Final report. CEFAS—contract report CO224, 169.
River Itchen Study Steering Group. (2004). River Itchen sustainability study, final technical report, by Halcrow Group Ltd, Wiltshire, England.
Scott, A., & Beaumont, W. R. C. (1993). Improving the survival rates of Atlantic Salmon (Salmo salar L.) embryos in a chalk stream. Institute of Fisheries Management, Annual Study Course: Cardiff.
Solomon, D. J. (2002). Dibden terminal inquiry—Proof of evidence of David Solomon Topic: Fisheries and Fish, 55.
Solomon, D. J. (2004). Development of action profiles for salmon, River Itchen sustainability study technical Ref: E(AP)02, Report to the Environment Agency.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Appendix: Flow Thresholds Set with Reference to Local Investigations on the River Itchen—Summary
Appendix: Flow Thresholds Set with Reference to Local Investigations on the River Itchen—Summary
A trend linking invertebrate community variation and antecedent summer Q95 flow was identified. Based on multivariate ordination techniques, a statistically and ecologically significant community change was shown to occur as flows fell below 0.861–0.844 standardised flow units. Samples collected when flows were greater than or equal to 0.861 units contained typical chalk stream invertebrate communities, whereas those collected when flows were less than or equal to 0.844 units were already impacted. No samples were available when flows were between 0.861 and 0.844 standardised units. It is therefore not possible to be specific about the impacts of flow within this narrow range.
The community shift that occurs between 0.861 and 0.844 standardised flow units was evident at sites throughout the River Itchen catchment. The shift was primarily caused by a reduction in the abundance of macroinvertebrates that prefer fast-flowing water and are highly characteristic of the typical chalk stream community.
Figure 12.10 summarises the community change that occurs between 0.861 and 0.844 standardised flow units.
Ordination of River Itchen samples highlighting samples (in black) collected when summer Q95 flow was greater than or equal to 0.861 standardised flow units, and samples (in white) collected when summer Q95 flows were less than or equal to 0.844 units. These sample groups were shown to be significantly different (p = 0.001) (Source Exley 2006)
Rights and permissions
Copyright information
© 2018 Springer Science+Business Media B.V.
About this chapter
Cite this chapter
Cox, J., Özdemiroğlu, E. (2018). Water Abstraction from the River Itchen, Hampshire, United Kingdom. In: Lipton, J., Özdemiroğlu, E., Chapman, D., Peers, J. (eds) Equivalency Methods for Environmental Liability. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-9812-2_12
Download citation
DOI: https://doi.org/10.1007/978-90-481-9812-2_12
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-9811-5
Online ISBN: 978-90-481-9812-2
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)