Surface water management planning: guidance (2018)
Guidance to assist the responsible authorities in preparation of Surface Water Management Plans (SWMPs) to help with the management of surface water flooding.
6 Setting objectives
| Setting objectives: considerations and example outputs | |
|---|---|
| Considerations | Example outputs |
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6.1 Initial objectives
The FRM Strategies contain high-level objectives for surface water management. In general, these are:
- To avoid an increase in surface water flood risk (applies everywhere including SWMP areas).
- To reduce surface water flood risk (applies to SWMP areas at the town and city scale).
More detailed and localised objectives for reducing surface water flood risk should be set in line with responsible authorities’ assessment and understanding of flood risk ( Figure 6.1 and Table 6.1).
Table 6.1 Objectives for SWMPs
| Objective | Example |
|---|---|
| Reduce surface water flood risk | Areas where the greatest risk of surface water flooding has been identified (flooding hot spots) through modelling or historical flood events. Areas where there are specific facilities or infrastructure that carry a significant risk, e.g. hospitals or roads. |
| Accept flood risk and maintain existing actions | Areas where there are existing actions (mainly structural) to reduce surface water flood risk that require maintenance. |
| Improve understanding of surface water flood risk | Areas where further modelling is required to understand flood risk and decide if action needs to be taken to reduce it. This can apply to the whole urban area or to more localised areas, depending on the outcome of the validation stage ( Section 4.4). |
Indicators for objectives
The indicators for the flood risk objectives will generally be the at-risk receptors at different spatial scales, summarised under the understanding of flood risk stage (i.e. the flood risk statistics for the SWMP area and more localised areas). By monitoring and reviewing these indicators, the success or otherwise of achieving the objectives can be assessed ( Table 6.2).
Other indicators could be used to monitor how sustainable the actions are or how many multiple benefits are being realised through joint projects. Possible examples include the development of green and blue infrastructure and networks, area of impermeable surface changed to permeable, and volume of surface water stored above ground and below ground. Further information on monitoring actions is given in Chapter 10.
Prioritising objectives
Prioritising objectives will help to clarify which factors need to be dealt with first, in the short term, and which can be tackled in the longer term ( Figure 6.1). Exact timescales are not required initially, but can be refined once options have been identified and more information on funding and implementation becomes available.
Initially objectives should be prioritised, in consultation with relevant authorities, on the basis of flood risk. These initial priorities may nevertheless change where opportunities for co-ordination or joint working arise.
When prioritising, a number of criteria can be used. There is no single, recommended method but factors to consider include:
- Surface water flood risk (using information on impacts of flooding).
- Surface water flood risk to priority receptor groups, e.g. homes at risk in more socially vulnerable areas.
- Locations with a history of flooding.
- Areas where there is no history of flooding but which are predicted to flood and should therefore be treated with caution, particularly where more detailed models are not available. It is sensible to balance predicted and actual flooding information when prioritising.
- Locations where there are opportunities for joint working (e.g. making management more cost-effective and delivering multiple benefits).
Figure 6.1 Example of prioritising objectives in the SWMP
Table 6.2 Example of initial objectives and indicators for an SWMP
| Location / hotspot | History of flooding Confidence in data | Initial objective | Initial priority | Objective indicators | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Annual Average Damage ( AAD) (all return periods) | Businesses 1:200 yr | Homes 1:200 yr | Homes in socially vulnerable areas 1:200 yr | Community facilities 1:200 yr |
Listed buildings 1:200 yr | Infrastructure 1:200 yr |
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| Whole Town | History of surface water flooding. | Avoid an increase in surface water flood risk in Whole Town. | High | £395,000 | 25 | 90 | 65 | <10 | 0 | <10 electricity sub- stations, 1.5km road |
| Reduce surface water flood risk in Whole Town. | ||||||||||
| Neighbourhood A | History of significant surface water flooding but modelling shows low risk. Poor confidence in modelled data. | Improve understanding of surface water flooding in Neighbourhood A. | High | £1,000 | 0 | <10 | 0 | 0 | 0 | 100m road |
| Burn B | Observed flooding matches modelled data. Good confidence in modelled data. | Reduce surface water flood risk from Burn B. | Medium | £80,000 | 0 | 25 | 15 | 0 | 0 | 10m road |
| Burn C | Observed flooding in area but existing structure to manage risk not shown in modelled data. | Maintain existing structure at Burn C. | On-going | Existing structural action reduces flood risk – provides 1:100 yr standard of protection, £20,000 AAD damages avoided, 20 homes protected 2 businesses protected |
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| Neighbourhood D | Observed flooding matches modelled data. Good confidence in modelled data. | Reduce surface water flood risk in Neighbourhood D. | High | £90,000 | <10 | 20 | 15 | 1 Hospital | 0 | 1 electricity sub-station, 20m road |
| Road E | No history of surface water flooding but area could be at risk. Medium confidence in modelled data. | Reduce surface water flood risk at Road E. | Medium | £10,000 | <10 | <10 | <10 | 0 | 0 | 500m road |
6.2 Consultation and co-ordination
Consultation at this stage is important for identifying other projects that could be co-ordinated or implemented jointly with surface water flood management to aid delivery and realise multiple benefits (e.g. urban regeneration, green networks and Scottish Water work). At this point the local authority will understand where surface water flood risk is greatest and have prioritised objectives in place (priorities which may change after consultation).
Information from all stakeholders should be shared and communicated clearly. Providing this information in maps and GIS formats will also help stakeholders to identify opportunities for joint working or co-ordination. Information on what data to share can be found in Table 3.1.
6.3 SMART objectives
Objectives should be updated with more detail on timescales (i.e. made SMART) after actions have been identified and funding and implementation have been confirmed. This information should form part of the final action plan (see example in Table 8.1).
If, after undertaking the action appraisal, it is not feasible to reduce flood risk in any locations then the priority for dealing with the risk can be lowered (e.g. it may become feasible in the future through other projects or opportunities). Alternatively, the ‘reduce’ objective could be removed from the SWMP, leaving in place the ‘avoid’ objective where non-structural actions, e.g. land use planning, will still apply.
Table 6.3 Definition of SMART objectives
| Specific | Objectives relating to high-risk areas or specific receptors. |
|---|---|
| Measurable | Key flood risk indicators that show what is at risk in each SWMP area/flooding hotspot, or the specific receptor at risk. |
| Achievable | Tied to responsible bodies’ capacity and the level of funding at local and national level. |
| Relevant | Having the aim of reducing overall flood risk. While multiple benefits are a key part of sustainable flood management, they will not form part of the objectives. Rather, they will be considered as part of the selection criteria of the appraisal method. Other objectives can be used to determine the sustainability of actions or their ability to link in with other processes, e.g. green and blue network development, volumes of water stored above ground, area of green space created, or volumes of water reduced in the combined sewer. |
| Time-Bound | Where appropriate, deadlines will be set for achieving objectives. Deadlines can be set in line with FRM planning cycles, i.e. 2021, 2027, 2033 etc. |
Contact
Gordon Robertson: Flooding_Mailbox@gov.scot
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