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Comments on River Wey Catchment Vision: Consultation Draft (June 2014, Wey Landscape Partnership)
From: Greening Godalming. Contact: Heather Hullah (heather.hullah@zen.co.uk), cc. Alan Hamilton
(alanchamilton@btinternet.com)
Date: 14 July 2014
1. This is a response by Greening Godalming to a request for comments on a Consultation Draft of a River
Wey Catchment Vision (June 2014). Greening Godalming is a community group concerned with the
impact on our community of climate change, including raising awareness within the community of
steps that they might take to help combat it. Our comments here are specifically on flooding, especially
with respect to Godalming and predicted climate change. Godalming is bisected by the River Wey. The
southeast of England received its highest winter rainfall ever recorded in the winter of 2013/4 and
endured its worst ever winter flooding. 160 properties in Godalming and Guildford (downstream) were
flooded1.
2. The need to consider climate change in the Vision is recognised in the Consultation Draft (Sections 1.4,
7.3 and 7.6), but not specifically in relation to flood risk. The reality of human-made climate change is
accepted by a global scientific consensus2. The Met Office (UK) estimates that temperatures will be up
to 30C warmer in the south of England by 2100 compared with today and that there will be an increase
in the frequency of rainfall extremes; an increase in winter rainfall is predicted and an increased risk of
winter flooding3. A recent assessment by the Met Office (June 2014), using finer-scale modelling than
hitherto, concluded that flood risk will become greater in the summer (as well as the winter), due to an
increase in localised heavy summer downpours4. We conclude that flooding in Godalming on the scale
of the 2013/4 event has a high probability of recurring and, indeed, becoming more severe. We
recommend that the flood risk aspects of the Consultation Draft be revised, taking account of
predicted climate change.
3. The principal remark in the Consultation Draft on flood risk is: “Extreme weather, existing buildings in
floodplains and limited funding mean flood incidents in Surrey can’t be stopped.” (Section 6.5). We
recommend that this statement be revisited taking a more proactive attitude to containing flood risk.
The sooner steps to combat the consequences of predicted climate change are taken, the easier and
cheaper they are liable to be.
4. The main measure to reduce flood risk mentioned in the Consultation Draft is through increasing water
storage in the catchment through restoration of flood plains (Section 11). Dredging of the river channel
can also influence flooding, though may merely serve to “speed the problem to another part of the
catchment” (Section 6.5). How weirs are manipulated along the river will also influence whether and
where flooding occurs.
The Consultation Draft states that “main river flooding [is] the responsibility of the Environment
Agency” (Section 7.7). A River Wey Flood Risk Management Strategy was published by the Environment
Agency in 2012 aimed at managing flood risk over the next 100 years5. A principal recommendation in
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Surrey Advertiser 13 June 2014.
http://www.climatechange2013.org/images/report/WG1AR5_SPM_FINAL.pdf
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http://www.metoffice.gov.uk/media/pdf/t/r/UK.pdf
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Kendon, E.L. et al. (2014). Heavier summer downpours with climate change revealed by weather forecast resolution
model. Nature Climate Change 1 June 2014. DOI:10.1038/NCLIMATE2258.
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https://www.gov.uk/government/publications/river-wey-flood-risk-management-strategy/river-wey-flood-riskmanagement-strategy
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this Strategy was that the Environment Agency should continue to maintain the existing flood risk
assets that were built as part of a River Wey Improvement Scheme in the 1930s. However, an update
on the strategy subsequently posted on the Environment Agency website (presumably following the
serious flooding along the river in the winter of 2013/4) states that “the existing River Wey
improvement scheme has little flood management value” and therefore that “the Environment Agency
has decided to find a more sustainable solution”. Greening Godalming supports the decision of the
Environment Agency to find a more sustainable solution to the management of flood risk along the
River Wey.
The River Wey became a pilot catchment area to trial a catchment-based approach to water
management in 2012. This approach to water management is now required of Member States under
the EU Water Framework Directive (adopted by the EU in 2000). A further EU directive (Directive
2007/60/EU), dealing specifically with flood assessment and risk, was adopted by the EU in 2007. It
requires Member States to assess water courses at risk from flooding, to map the flood extent and
assets and humans at risk in these areas and to take adequate and coordinated measures to reduce this
flood risk. This Directive also reinforces the rights of the public to access this information and to have a
say in the planning process. Greening Godalming agrees that a catchment-based approach is
appropriate for water management along the River Wey.
Various management measures that could have an influence on flood risk are mentioned in the
Consultation Draft, but these relate only to the river itself (including its banks) and flood plains. We
urge the Environment Agency to take the whole catchment into consideration in assessing flood risk,
meaning the entire catchment, not just the probably less than 1% of the total area covered by the river
and its flood plains. This could reveal more avenues of intervention to reduce flood risk than are
presented in the Consultation Draft. The Consultation Draft mentions that, of 557 reaches in the Wey
system used for a survey, “44 % are bordered by pasture and grazing, 25% by woodland, 25% by
suburban, urban, recreation/mown, industrial or derelict land and 2.1% by wetlands” (Section 4.3.3.).
The relevance of these figures to flood risk is not clear. The lengths of ‘stretches’ are not given and may
be variable, so the figures may not be indicative of the linear extent of these land types. The
relationships between lengths of stretches and aerial extent of land types is not stated and, further, it
not clear whether distance from the river of a given area of a particular land type is significant.
Both surface water and groundwater flooding occur in the River Wey catchment. A Flood Risk
Assessment Report for the Waverley part of the River Wey catchment reported 26 incidents of flooding
between September 2000 and March 2004, 9 attributable to surface water flooding and 14 to
groundwater flooding6. The flooding involved ‘waterlogged or flooded gardens or properties’, with no
incidents of house flooding being specifically noted. We urge the Environment Agency to consider
both surface water flooding and groundwater flooding in its assessments of future flood risk.
If a whole catchment approach is taken by the Environment Agency to flooding and, considering the
need recognized by the Agency to find a “more sustainable solution” to the management of flood risk,
then the Agency may need to revise its hydrological modelling of the River Wey, taking account of how
land in the catchment as a whole is used. If so, we urge the Environment Agency to undertake the
analysis at an appropriate level of detail with respect to all the major categories of land use
identified (e.g. agriculture, forestry, urban). For instance, it may be that the hydrological
characteristics of agricultural land that is left bare over winter (for spring planting of crops) may be
different from those of permanent pasture, with higher surface run during extreme rainfall events with
the former.
If it is found that the way that the land is managed in the whole landscape has a significant influence
over flood risk, then we urge the Environment Agency to review its links with relevant government
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Flood Risk Assessment submitted to Surrey County Council in 2009 to inform its Surrey Mineral Plan.
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agencies (e.g. perhaps DEFRA, Forestry Commission; Planning Departments, as appropriate) to
ensure that these organizations are aware of the implications for flood risk of their policies and adopt
mitigation measures, as needed.
The Draft Consultation states that components should be selected that provide ongoing monitoring
variables and/or measurable outcomes to assess success (Section 12). We recommend that, if
necessary, the Environment Agency revises the variables that it monitors in the catchment relevant
to flood risk prediction.