Flood and coastal erosion risk management funding for local authorities
Published 25 March 2024
Summary
In 2020 the National Audit Office recommended that Defra “develop a clear understanding of whether flood risk management funding for local authorities is adequate to cover the level of flood risk individual authorities face”.
This report has been prepared in response to this recommendation and analyses local authority spend on flood and coastal erosion risk management (FCERM).
The analysis considers the total amount of current revenue spending by Lead Local Flood Authorities (LLFAs) on FCERM in relation to risk. The analysis shows between 2008 to 2009 and 2021 to 2022 revenue spend by local authorities on flooding and coastal erosion risk management (FCERM) increased from £90 million to £134 million. This is almost 50% in nominal terms.
This report does not consider whether this spend is sufficient to meet a LLFA’s risk management needs. This depends on local objectives for managing risk, which differs between authorities. LLFAs are required to set objectives for managing local flood risk as part of a local strategy. Local objectives vary based on local priorities and circumstances. This means there is no definitive quantitative measure of how much a LLFA should spend to meet their statutory flood and coastal erosion risk management duties. The level of risk and the opportunities to manage risk will vary by authority based on a number of factors. This includes geography, the presence and condition of flood assets and number of properties at risk.
Average revenue spend by LLFAs between 2015 to 2016 and 2021 and 2022 was modelled against risk and institutional factors. This analysis found LLFAs spend on average per year:
- £559,000 on flood risk management with an additional £15,000 in the case of Unitary authorities
- £21 per property at significant risk of flooding from surface water and £29 per property at significant risk of flooding from the rivers and the sea
- £1,100 for every kilometre of ordinary watercourse
The analysis also found that LLFAs in more deprived areas spend more on flood and coastal erosion risk management. A higher Indices of Multiple Deprivation number means a local authority is less deprived. On average, local authorities in a particular deprivation decile spend £55,000 more on flood and coastal erosion risk management than local authorities in the next deprivation decile up (meaning local authorities in less deprived areas).
The top 10% of LLFAs who spent the most on FCERM spent around £437,000 per year more than the average local authority (or 77% more).
By comparison, the 10% of LLFAs who spent the least on FCERM spent around £354,000 per year less than the average local authority (or 63% less).
Differences in spending between individual authorities could reflect a range of factors. For example, the frequency and severity of flooding within a local authority, associated repair and reporting costs during the period covered by the analysis, or differences in local priorities.
Local spend on flood and coastal erosion risk management shows volatility and can change abruptly from one year to the next depending on recent flood events and other factors.
The final local government finance settlement for 2024 to 25 makes over £64.7 billion available. This is an increase in Core Spending Power of up to £4.5 billion, or 7.5% in cash terms from 2023 to 24. Also, the Government announced another £3 million in grant funding for 2024 to 25 to support local authorities that are severely impacted by the increase in levies from internal drainage boards.
The majority of local government funding is not ringfenced, recognising that local authorities are best placed to decide how to meet local priorities in their areas, including on flood risk management.
The government is committed to making sure that funding allocations for councils are based on an up-to-date assessment of their needs and resources.
Other sources of funding
Outside the scope of this analysis, the government is investing a record £5.2 billion between 2021 and 2027 in flood and coastal erosion projects to better protect communities across England. And a further £200 million to support over 25 local areas over 6 years to take forward wider innovative actions that improve their resilience to flooding and coastal erosion.
Flood infrastructure is also eligible for capital funding from the government’s Levelling Up Fund, Shared Prosperity Fund and Rural England Prosperity Fund, where that infrastructure meets the wider objectives of the Fund.
Next steps
The government is committed to supporting local authorities to bolster skills and capacity, so that every community can improve local resilience to flood and coastal erosion risk.
The government will keep the findings of this report under review as more data emerges.
Introduction
The government’s 2020 Flood and Coastal Erosion Risk Management (FCERM) Policy Statement included a commitment to review local government funding for statutory flood and coastal erosion risk management functions. This includes the way it is allocated, to make sure that it is fair and matches the needs and resources of local areas, recognising that areas face different risks.
In November 2020, the National Audit Office recommended that government “develop a clear understanding of whether flood risk management funding for local authorities is adequate to cover the level of flood risk individual authorities face”.
Then in February 2021, the Public Accounts Committee issued a recommendation to ”identify areas where there is likely to be a shortfall in local authority resources and private sector contributions to ensure the effective management of flood risk in local areas”.
In February 2023, the government confirmed that a Review of Relative Needs and Resources and a reset of accumulated business rates growth will not be implemented in this Spending Review period. The government remains committed to improving the local government finance landscape in the next parliament.
This report responds to recommendations made by the National Audit Office and the Public Accounts Committee to better understand the current local government FCERM funding environment and inform future policy.
Understanding risk
Local authorities in England have significant variations in both their physical geography (such as coastal, rural, urban, mountainous, flat) and human geography (such as population density, deprivation, economy). They also face different types of flood risk at varying degrees of severity. For example, an area may be at risk from surface water flooding while also being at risk from fluvial (river) flooding. Local authorities with coastlines must also manage risks from coastal flooding and erosion.
The Environment Agency has a statutory duty to produce an annual Flood and Coastal Erosion Risk Management report. This report sets out the current level of risk and investment in flood and coastal erosion risk management in England.
The report sets out the number of properties in England at very low, low, medium or high risk from river and sea flooding, and from surface water flooding. The data shows the number of residential properties at risk under each category, and the total number of properties. The data also shows the number of properties at risk from both surface water and river and sea flooding. The data provides a national picture of risk in England.
As set out in the Environment Agency report, the number of properties at risk from flooding and coastal change in any given year and in any given location will change over time due to a range of factors. This includes the impacts of climate change and investment in building and maintaining flood defences.
The Environment Agency uses flood mapping and modelling to understand the risk of flooding at national and local levels. The EA’s National Flood Risk Assessment shows there are 77,000 fewer properties with a medium to high risk of flooding from rivers and the sea in 2021 to 2022 compared with 2015 to 2016 (a medium or high risk is equal to or greater than 1% annual likelihood of flooding). This indicates an 8.5% reduction in risk across the nation (there was a change in methodology between 2015 to 16 and 2021 to 22 which may impact on this figure).
More detailed local assessment of risk is set out in Flood Risk Management Plans (FRMPS) and Local Flood Risk Management Strategies (LFRMS). Each Lead Local Flood Authority (LLFA) has a Local Flood Risk Management Strategy. Both FRMPS and LFRMS include requirements to consider funding sources for actions set out within plans.
Skills and capacity
Local authority skills and capacity to manage local flood risk may also affect spend. In 2019 to 2020, almost a third of LLFAs in England did not have an up-to-date register of flood risk assets available to the public, despite this being a statutory requirement under the Flood and Water Management Act 2010.
In 2019, the Government commissioned an independent review into surface water flood risk responsibilities. The review looked at the profile of the workforce dedicated to flood and coastal erosion risk management.
As part of the review 95 of the 152 LLFAs in England, responded to a survey as to how many posts there are within their LLFA teams. The answers ranged from 0 to 38. The mean average was 5 and the median average was 3. The numbers that were given most frequently were one and 2 (21 answers for each). The review acknowledged that some authorities rely upon partnership, agency, or contractor arrangements and that LLFAs are also of significantly differing sizes, with significantly differing scales of task to cover.
A 2021 survey of Local Authorities, sponsored by the Local Government Association, showed that there are capacity challenges in preparing for a range of climate risks and impacts, including flooding and costal erosion. The most frequently reported barriers were:
- amount of funding (97% to a great or moderate extent)
- accessibility of funding (94%)
- lack of workforce capacity (92%)
- conditions of funding (87%)
- internal skills and expertise (77%)
- and reliability of funding (74%)
Government action
The Environment Agency’s FCERM Strategy Roadmap to 2026 provides a range of actions to support local authorities to build skills and capacity. The roadmap includes actions to:
- provide training, tools and support to help practitioners develop skills and capabilities to prepare and adapt to flood risk
- provide ‘green finance’ training to develop the skills and capabilities needed to build new finance partnerships and secure extra funding for projects
- develop best practice and digital tools to equip risk management authorities with the skills to include adaptive approaches into their projects, investments and strategic plans
- work with planning authorities to ensure that spatial plans and growth strategies reflect adaptation
- support lead local flood authorities to promote best practice in incorporating sustainable drainage systems for new development
- create new engagement skills courses for practitioners to build capability in collaboration and enhancing public understanding of a range of flood resilience actions
The Environment Agency is currently developing a new National Flood Risk Assessment. This will provide a single picture of current and future flood risk from rivers, the sea and surface water. It will use both existing detailed local information and improved national data.
The new risk assessment will be available as open data. It will provide risk management authorities, infrastructure providers, insurers and members of the public with more accessible and trusted data and information for making good investment decisions. It will be available by the end of 2024.
The government is taking steps to support local authorities to improve their management of local FCERM assets. This includes a review of the statutory powers and responsibilities to map, monitor, inspect and maintain all assets. The review will examine the extent of statutory and non-statutory powers, and responsibilities associated with FCERM assets and their maintenance across all flood risks and coastal erosion, to explore if they are effectively understood, enacted and regulated.
To further support LLFAs, the government provided £3.5 million (£2 million in 2019 to 2021 and £1.5 million in 2022 to 2023) to increase surface water flood risk mapping in 59 lead local flood authority areas. These new maps provided 4.6 million people with more detailed information.
Looking ahead, government has committed to reform local flood risk management planning by 2026. This is so that every area of England will have a more strategic and comprehensive plan that drives long-term local action and investment.
Local government funding for flood and coastal erosion risk management
Variations in levels of risk, physical and human geography inform how much revenue a local authority might choose to spend on FCERM. Local authorities apply revenue funding to fulfil their statutory FCERM duties. These duties are set out in the Flood and Water Management 2010 Act and include the need to:
- develop, maintain, apply and monitor a strategy for local flood risk management in its area
- cooperate with other relevant authorities in the exercise of their flood and coastal erosion risk management functions
- record, investigate and publish reports on flooding incidents in the county and make the results available to the public
The Flood and Water Management 2010 Act also includes the need to establish and maintain a register of structures or features which, in the opinion of the authority, are likely to have a significant effect on flood risk in its area. It also requires a record of information about each of those structures or features, including information about ownership and state of repair.
To fund these duties a new burdens assessment was completed as part of the implementation of the Flood and Water Management Act 2010. This was reflected in the local government settlement.
The final local government finance settlement for 2024 to 2025 makes over £64.7 billion available. This is an increase in Core Spending Power of up to £4.5 billion or 7.5% in cash terms from 2023 to 2024. The Government also announced an extra £3 million in grant funding for 2024 to 2025, to support local authorities severely impacted by the increase in levies from internal drainage boards.
The majority of local government funding is not ringfenced recognising that local authorities are best placed to decide how to meet local priorities in their areas, including on flood risk management.
Local government spending on flood and coastal erosion risk management
The amount of revenue local authorities spend on FCERM can be found in the Department for Levelling Up, Housing and Communities (DLUHC) annually published Revenue Outturn. It is broken down by the following service areas:
- defence against flooding
- land drainage and related work (exclusive of special levies)
- land drainage and related work – special levies
- coast protection
- Environment Agency flood defence levy
The annual Revenue Outturn publication does not breakdown the spend lines by source of funding. It is therefore possible that outturn for Environment Agency flood defence levy spend includes some double counting. This is due to the fact that Regional Flood and Coast Committees partially redistribute this revenue back to local authorities to support capital programme construction.
Local authorities can also spend money on other activities which provide FCERM benefits but which are captured in other lines of expenditure (such as street cleaning, clearing of gullies). This type of expenditure is not captured in this analysis.
The average annual local authority revenue spend nationally on FCERM between 2015 to 2016 and 2021 to 2022 was £129.6 million in nominal terms. This consisted of:
- £28 million on defence against flooding
- £22 million on land drainage and related work (excluding special levies)
- £30 million on land drainage and related work, which are special levies
- £13 million on coast protection
- £37 million on Environment Agency flood defence levy
Between 2008 to 2009 and 2021 to 2022 local authority annual spend on FCERM increased by about 50% in nominal terms with 3 distinct time periods emerging (look at figure 1).
- Between 2008 to 2009 and 2016 to 2017 spend increased by 45%, from £90 million to £130 million
- Between 2016 to 2017 and 2018 to 2019 spend decreased by 7%, from £130 million to £122 million
- Between 2018 to 2019 and 2021 to 2022 spending increased by 9% from £122 million to £134 million
The significant increase between 2008 to 2009 and 2016 to 2017 could be due, in part, to the introduction of more statutory duties for local authorities as part of the Flood and Water Management Act 2010.
Figure 1: Local authority FCERM revenue spend between 2008 to 2009 and 2021 to 2022
Other funding sources available to local authorities
As well as local government funding, local authorities also have access to a range of capital funding sources to support local flood and coastal erosion risk management.
Local authorities are important delivery partners and benefit from the government’s flood and coastal defence investment programme. Defra invests Grant in Aid wherever flood risk is highest across the country and where it will benefit the most people and property. Defra uses a consistent set of criteria to fund schemes proposed by all Risk Management Authorities (RMAs), including local authorities. This approach is set out in the government’s Partnership Funding Policy.
Between 2015 and 2021, Government invested £2.6 billion in a floods capital programme. The Environment Agency and partners, including local authorities, completed more than 850 projects to better protect more than 314,000 homes, nearly 600,000 acres of agricultural land, thousands of businesses and major pieces of infrastructure.
Of the £2.6 billion Defra funding, approximately £540 million was allocated to local authorities for their defence improvement projects. In addition, through the Partnership Funding policy, over £632 million of contributions from private and public sources were generated to complement government’s investment over this period.
The government announced in March 2020 that the amount invested in flood and coastal erosion schemes would be doubled in England to £5.2 billion between 2021 and 2027, to better protect communities across England. Every English region is forecast to get more investment in flood and coastal defences in this programme compared to the previous 2015 to 2021 investment programme. As of the end of September 2023, the EA and other Risk Management Authorities, including local authorities, have successfully secured £579 million in partnership contributions to complement government investment.
Figure 2: Table showing investment from the £2.6 billion floods capital programme and the first year of the £5.2 billion floods capital programme. These figures are broken down by Office of National Statistics (ONS) regions.
ONS Region | £2.6 billion capital programme average annual investment 2015 to 2021 (£millions) | £5.2 billion capital programme investment 2021 to 2022 (£millions) |
---|---|---|
East Midlands | £47 | £71 |
East of England | £50 | £73 |
London | £25 | £32 |
North East | £13 | £13 |
North West | £55 | £108 |
South East | £72 | £115 |
South West | £44 | £94 |
West Midlands | £21 | £39 |
Yorkshire and the Humber | £88 | £130 |
As well as the government’s £5.2 billion investment, we are also investing £200 million to support over 25 local areas over 6 years to take forward wider innovative actions that improve their resilience to flooding and coastal erosion. This funding is directly supporting local authorities.
More widely, flood infrastructure is eligible for funding from the government’s Levelling Up Fund, Shared Prosperity Fund and Rural England Prosperity Fund, where that infrastructure meets the wider objectives of the Fund. These Funds can
be used to support local partners to meet their flood and coastal erosion risk management commitments.
Figure 3: Table of funding sources available to local authorities which can support local flood and coastal resilience (depending on fund rules, eligibility criteria and awarding of funding)
Funding source | Amount (in billions)* |
---|---|
Local Government Finance Settlement | £64.7 (2024 to 2025) |
Flood defence capital programmes | £1.5 (2005 to 2010) £1.7 (2010 to 2015) £2.6 (2015 to 2021) £5.2 (2021 to 2027) |
Partnership funding contributions | £0.6 (2015 to 2021) |
£0.6 (2021 to September 2023) | |
Flood and coastal resilience innovation programme | £0.2 (2021 to 2027) |
Levelling Up Fund | £4.8 (2021 to 2025) |
UK Shared Prosperity Fund | £2.6 (2022 to 2025) |
Rural England Prosperity Fund | £0.1 (2023 to 2025) |
*The majority of funds in this table are capital with the exception of the Local Government Finance Settlement. Some capital funds may include a small amount of revenue to support delivery. Figure 2 does not provide a complete list of capital and revenue funds available to local authorities.
Lead local flood authority modelled spend
There is no definitive quantitative measure of how much a LLFA should spend to meet their statutory flood and coastal erosion risk management duties. The level of risk and the opportunities to manage risk will vary by authority based on a number of factors. This includes geography, the presence and condition of flood assets and number of properties at risk.
Methodology
Available data can be used to estimate the level of risk faced in each LLFA (some risk data is only available for LLFAs so other local authorities are not included in this analysis). This can be compared to the actual revenue spend taken from annually published DLUHC data, which provides a breakdown of local authority spending on different local services.
Analysis can estimate which factors LLFAs consider when deciding how much to spend on FCERM and how much they spend on average depending on these factors. For example, whether LLFAs consider the number of properties at risk and, if they do, how much they spend, on average, per property at risk. The factors that this analysis has found to be more influential on local spend on FCERM are risk factors and institutional factors.
Risk factors are the:
- number of properties at significant risk of flooding from surface water
- number of properties at significant risk of flooding from rivers and the sea
- length of ordinary watercourse – defined as every river, stream, ditch, drain, cut, dyke, sluice, sewer (other than a public sewer) and passage through which water flows and which does not form part of a main river
Institutional factors are:
- Unitary authority
- deprivation
The revenue spend for the 152 LLFAs, averaged between 2015 to 2016 and 2021 to 2022, was then modelled against the risk and institutional factors. This shows that LLFAs spend on average per annum:
- £559,000 on flood risk management with an additional £15,000 in the case of Unitary authorities
- £21 per property at significant risk of flooding from surface water and £29 per property at significant risk of flooding from the rivers and the sea
- £1,100 for every kilometre of ordinary watercourse
The analysis also found that Lead Local Flood Authorities in more deprived areas spend more on flood and coastal erosion risk management. A higher Indices of Multiple Deprivation number means a local authority is less deprived. On average, local authorities in a particular deprivation decile spend £55,000 more on flood and coastal erosion risk management than local authorities in the next deprivation decile up (meaning local authorities in less deprived areas).
This average spend is then compared to the risk and institutional factors. This is to model the amount local authorities are spending above or below the average of other local authorities with a similar level of risk. This is by reference to the number of properties at significant risk or the length of ordinary watercourses within their boundaries.
For example, according to the model an average unitary local authority with 5,000 properties at significant risk from the rivers and the sea would be spending £679,000.
£559,000 base spend for all local authorities, plus £15,000 for unitary authorities, plus £21 for each of the 5,000 properties at significant risk of flooding from rivers and the sea = £559,000 + £15,000 + (£21 x 5,000) = £679,000.
An authority which spent £747,000 would be spending 10% above the average of local authorities with an equivalent level or risk.
Figure 4: Table showing the distribution of LLFA revenue spend compared to the average broken down by percentiles.
Percentile | Revenue spend compared to the average (in thousands of pounds) | % above or below average |
---|---|---|
Highest 10% of spenders | £437 | 77% |
Highest 25% of spenders | £146 | 26% |
Middle 50% of spenders | -£54 | -10% |
Lowest 25% of spenders | -£209 | -37% |
Lowest 10% of spenders | -£354 | -63% |
As figure 4 shows, the highest 10% of spenders spend about £437,000 more than the average local authority (or 77% more), where as the lowest 10% of spenders spend about £354,000 less than the average local authority (or 63% less).
There are a number of caveats to this analysis. The analysis excludes capital spend. In addition, LLFAs’ revenue spending will depend on local objectives for managing flood risk. The analysis compares revenue spend against the average level and therefore does not account for local authority risk appetite or local priorities.
The analysis considers historic revenue spend which does not directly relate to future spend. If there is a major flood in the future, a LLFA’s revenue spend will likely increase due to having to make repairs to damaged flood risk assets, produce extra reports on the impacts caused by the flooding, and local expectations.
The analysis demonstrates that local spend in flood and coastal erosion risk management shows volatility and can change abruptly from one year to the next depending on the weather and other factors.
A 7-year average is a relatively short period and big differences between actual and modelled spend after a major flood event tend to gradually disappear with time.
The analysis considers the total amount of current spending by LLFAs on FCERM in relation to risk. The analysis does not consider whether the total or the average is sufficient to meet a LLFA’s risk management needs, as this would depend on local objectives for managing risk which may differ. LLFAs are required to set objectives for managing local flood risk as part of a local strategy. Local objectives will differ based on local factors and priorities.
The method used in this report only takes account of the factors outlined above. It is estimated this accounts for 55% of modelled spending on FCERM by LLFAs. The remaining 45% of modelled spending on FCERM by LLFAs will be influenced by other factors. For example, LLFAs that have been recently flooded will tend to spend more than the model predicts in the years immediately after the flood event. LLFAs that have not been flooded recently will tend to spend less than the model predicts. Because of this, the model has a 22% margin of error.
Finally, the data used for risk is not exhaustive. For example, although LLFAs are required to have a register of up-to-date flood risk assets, there are some data gaps. This means understanding of flood risk assets and associated maintenance costs is partial.
Alternative datasets could be used as a proxy for the level of risk faced in an area. This may result in a different level of risk and so modelled spend for an area.
Conclusion
The report provides an analysis of the amount individual local authorities spend on flood and coastal risk management activities, relative to their level of risk. This analysis shows LLFAs spend on average over £559,000 per year on flood risk management.
Comparing the average LLFA spend to their risk and institutional factors shows that the top 10% of highest spenders spend about £437,000 per annum more than the average local authority (or 77% more). Where as the lowest 10% of spenders spend about £354,000 per annum less than the average local authority (or 63% less).
The difference between individual authorities could be due to the frequency and severity of flooding within a local authority, and the associated repair and reporting costs during the period covered by the analysis. It could also reflect differences in local priorities and circumstances.
Local spend on flood and coastal erosion risk management shows volatility and can change abruptly from one year to the next depending on the weather and other factors. LLFAs are required to set objectives for managing local flood risk as part of a local strategy. Local objectives will differ based on local factors and priorities and this will impact spend.
The report also considers trends in the total revenue spend on FCERM by all local authorities across England, including LLFAs. The report found that local authorities across England spend, on average, around £130 million each year on FCERM.
In addition, between 2008 to 2009 and 2021 to 2022 revenue spend by local authorities on flooding and coastal erosion risk management (FCERM) increased from £90 million to £134 million – almost 50% in nominal terms. However, ‘Core Spending Power’ was created as a comparable measure of local government funding for the multi-year settlement in 2016 to 2017, with 2015 to 2016 as the base year. Due to changes in the function and financing of local government, comparable data is not available prior to 2015 to 2016.
It was government policy from 2013 to 2014, for government to stop collecting all national non-domestic rates centrally to distribute that out via the Revenue Support Grant. Instead the government would allow councils to retain 50% of their non-domestic rates locally. The shift to business rates retention directly contributed to the drop in the Revenue Support Grant. But councils were still funded in line with their settlement funding assessment and had access to other resources such as council tax. For these reasons, wholly accurate comparison of the current Local Government Finance system and before 2013 to 2014 is not possible.
It is important to note that capital funding available to local authorities is outside of the scope for this analysis. The analysis is focussed on revenue spend and therefore does not represent the full picture.
On average between 2015 to 2016 and 2021 to 2022 revenue made up 44% of local authority spend with the remaining 56% being capital. However, this does not include direct spend within an authority by the Environment Agency through programmes like the £5.2 billion capital investment programme. In 2021 to 2022 this totalled around £742 million across England.
Next steps
The government will keep the findings of this report under review as further data emerges.
The government is committed to ensuring that funding allocations for councils are based on an up-to-date assessment of their needs and resources.
The local government finance settlement for 2024 to 2025 makes over £64.7 billion available. This is an increase in Core Spending Power of up to £4.5 billion or 7.5% in cash terms from 2023 to 2024. In addition, the Government announced an extra £3 million in grant funding for 2024 to 2025 to support local authorities severely impacted by the increase in levies from internal drainage boards.
The majority of local government funding is not ringfenced, recognising that local authorities are best placed to decide how to meet local priorities in their areas, including on flood risk management.
Alongside the local government finance settlement, Defra and the Environment Agency are taking forward a range of actions to further support Lead Local Flood Authorities in the delivery of their flood risk management duties. The FCERM Strategy Roadmap to 2026 published in June 2022, sets out a number of actions to further support local authorities to manage local flood risk.
The Government announced in March 2020 that the amount invested in flood and coastal erosion schemes would be doubled in England to £5.2 billion between 2021 and 2027 to better protect communities across England from flooding and coastal erosion. Local authorities can apply for capital funding to develop flood risk management schemes from the government’s flood and coastal erosion risk management investment programme.
Additional funding of £200 million over six years is supporting over 25 local areas to take forward wider innovative actions that improve their resilience to flooding and coastal erosion.
Taken together, the government is committed to supporting local authorities to bolster skills, capacity and resources so that every community can improve local resilience to flood and coastal erosion risk.