Integrated catchment management: from rhetoric to reality in a Scottish HELP basin
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Transcript of Integrated catchment management: from rhetoric to reality in a Scottish HELP basin
Integrated catchment management: from rhetoric to reality in a Scottish HELP basin
Alan Werritty 1, Chris Spray1, Tom Ball 1 Mike Bonell 1, Josselin Rouillard 1, Alan MacDonald 2, Luke Comins 3 and
Roy Richardson 4
1 UNESCO Centre for Water Law, Policy and Science, University of Dundee
2 British Geological Survey3 Tweed Forum
4 Scottish Environment Protection Agency
Outline
• UNESCO HELP programme: promoting ‘healthy rivers’
• Policy drivers for river restoration: Eddleston Water
• Characterisation and current status
• Proposed measures
• Opportunities, constraints and barriers
• Conclusions
UNESCO HELP programme
• Hydrology for the Environment, Life and Policy (HELP) established by UNESCO in 1999
• Global network of c. 90 basins “delivering social, economic and environmental benefits to stakeholders through research towards sustainable and appropriate use of water”
• Articulation between stakeholders and scientists means breaking the paradigm lock yielding rapid and agreed solutions and, if needed, resetting policy.
• River Tweed designated a HELP basin in 2008 –Eddleston Water proposed for river restoration 2009
Paradigm lock in integrated catchment management
Policy drivers for river restoration: Eddleston Water
Two main policy drivers:
• EC Water Framework Directive => Water Environment and Water Services (Scotland) Act 2003: Eddleston Water characterised as having “poor” ecological status
• EC Directive on the Assessment and Management of Floods => Flood Risk Management (Scotland) Act 2009: section 20 requires SEPA to assess whether the “alteration ... or restoration of natural features and characteristics ... could contribute to management of flood risk” often referred to as natural flood management
Characterisation and current status: topography
Eddleston Water a south-flowing tributary of Tweed draining 69 km2
• fractured greywackes mantled with highly variable covers of till, fluvio-glacial outwash and peat
• annual precipitation: 850 mm (valley floor)-1500 mm (summits)
• steeper slopes east of main stem => flashy runoff: gentler slopes west of main stem => delayed flow. QMED c. 23 m3s-1 , Q10 c. 38 m3s-1
• ideal exemplar of “source-pathway-receptor” flood risk management model
Characterisation and current status: land cover
Km
Land cover
• improved grassland dominate valley floor and lower slopes
• extensive Forestry Commission woodland west side of catchment
• small areas of fen and incipient wetlands adjacent to main stem
Characterisation and current status: landscapesSources
Pathways
Characterisation and current status: channelisation
Main stem sinuous c.1750: but extensively channelised by 1811
Minimal recovery since and main reason for ‘poor’ WFD status because of current hydromorphology
Roy Map
Characterisation and current status: habitat
Bad Moderate GoodPoor Satisfactory Very good
Characterisation and current status: fisheries
Characterisation and current status: hydrometry
Poor current hydrometry: 2 stage only gauging stations and 1 raingauge.
Estimates of bankfulldischarge on tributaries (blue) and main stem (yellow)
Waterheads: c. 3 m3s-1
Eddleston Village c. 10 m3s-1
Peebles c. 19 m3s-1
Characterisation and current status: flood risk
Source: JBA Consulting 2008
Scottish Borders Council identifies 589 properties within SEPA’s 1:200 year flood envelope.
Peebles flooded every 5-10 years.
Currently no structural defences, only flood warning scheme.
Annual flood Return Discharge
risk probability period (yrs) (m3s-1)
QMED 2 22.8
0.2 15 31.7
0.1 10 38.1
0.05 20 47.1
0.02 50 54.8
0.01 100 63.5
0.005 200 73.2
Characterisation and current status: summary
• fails to achieve WFD ‘good’ status –because of ‘poor’ hydromorphology
• channelised reaches of main stem poor habitat (poor mix of channel types, lack of riparian vegetation)
• highest runoff from eastern tributaries and rapid increase in downstream bankfulldischarge
• catchment ideal exemplar for flood risk management measures (source-pathway-receptor) no structural defences
Proposed measures: overall aim
... “to restore river and its whole catchment
whilst at the same time promoting
livelihoods of those who derive income
from the sustainable management of
farms, forests and fishery”:
• improved physical habitat;
• reduction in flood risk;
whilst promoting sustainable management of
farms, fisheries and forestry and recreational opportunities for tourists.
Proposed measures: typology
Groups of 15 measures:
1 and 2 designed to improve habitat (planting riparian vegetation
and restricting stock access to the channel);
3, 4 and 5 create more natural channel morphology (increased
sinuosity with decreased plane beds and greater differentiation into
pools, riffles and glides)
6, 7 and 8 (breaching/removing embankments, planting floodplain
forests, introducing large woody debris) to provide temporary flood
storage, increase roughness and enhance riparian habitat
9 to 15 to reduce flood risk by decreasing the rate at which runoff is
generated in source areas:
• by increasing infiltration and storage of surface and soil water
(9, 10, 11, 12 and 13)
• by slowing rate at which runoff is conveyed via tributaries to main stem (14, 15).
Proposed measures: location
Selected groups of measures:
A: breach/set back embankments, new fence margins, riparian woodland, wet woodland, large woody debris
C: re-meander channel, riparian woodland
L: Reduced stocking density, tributary woodland, floodplain forest
N: create ponds, wetlands, riparian woodland block ditches, large woody debris
Proposed measures: flood storage Site A
• Interviews with key stakeholders: Scottish Govt, SEPA, Tweed Forum, Scottish Borders Council, SNH, Tweed Foundation, Scottish Water, NFU(Scotland), Scottish Wildlife Trust, Country Landowners Business Association.
• Interviews with five landowners (three floodplain and two upland famers) middle-aged, male, long-term landowners in the valley (>30 years) with several sources of income.
Opportunities, constraints and barriers
Opportunities, constraints and barriers: institutional
• Legal constraints: EC Environmental regulation (Water Framework Directive and Habitats Directives) operation of statutory duties by SEPA and SNH;
• Land use policy: high quality agricultural land on floodplains for food or flood control? Delivery of agri-environmental schemes over longer timespans (eg planting woodlands);
• Land tenure: contrasting planning horizons for tenant farmers, owner-occupiers and large estates – value of multiple benefit measures (eg Coed Cymru project in Central Wales);
• Quality of science: nature of science evidence base crucial in persuading land managers;
Opportunities, constraints and barriers: farmers
• understand aspirations and land tenure systems of the farming community – a real opportunity and a threat;
• develop trust and a common vision for aims of the restoration programme;
• role of intermediary, stakeholder-led organisation, via technical and social support networks (Tweed Forum highly valued);
Opportunities, constraints and barriers: farmers
• local expert knowledge must be factored in to any planning;
• financial incentives must be set at the right level – to sustain farm units and to attract engagement;
• long-term, guaranteed contractual arrangements to deliver focused outcomes;
• simplicity in any contractual arrangements.
Conclusions
• Scientists lose some professional autonomy and deliver to agendas set by the stakeholders – this a challenging change;
• Significant time and effort to engage with the local community and landowners in framing project prior to implementation – building up trust key to success;
• “Politics is the art of the possible”. Insights in terms of potential legal, organisational, socio-economic, cultural and scientific barriers should facilitate next phase and increase chances of success;
• Crucial to work ‘with nature’ in ways that sustainably maintain livelihoods of those who derive their living from the river basin.