Water & Environmental Management
Key water and environmental management services in a little more detail.
Flood Risk Assessments
NPPF / SPP7 / PPS15 / TAN15 Flood Consequence Assessment
Increase your chance of planning success with a professional Flood Risk Assessment & Report by RPM Water Management Ltd.
We are experts in Flood Risk Assessments, dedicated to maximising planning application success.
At RPM Water Management we possess specialised skills in precisely evaluating and handling flood risks. We cater to a wide range of clients, from small-scale residential projects through to large-scale commercial contracts, providing them with a comprehensive and value-based approach.
When choosing our services, you can rest assured knowing you are receiving the best service in the sector. Our Flood Risk Assessment reports will provide you with a detailed analysis of any flood risks, along with comprehensive advice on how to mitigate that risk, maximise safe development potential, and ensure the safety and value of your development is protected, whilst meeting necessary planning guidelines.
A Flood Risk Assessment (FRA) is a report that evaluates the impact of flood risks to a site. Flooding can occur from different sources such as rivers, the sea, sewers, groundwater, reservoirs, and as a result of surface water run-off. Flood Risk Assessments are used to support planning applications to demonstrate that both the development, and occupants will be safe during the lifespan of the property. The report must include an assessment of the relevant risks, and a suitable and compliant mitigation strategy.
An FRA should evaluate the risks to a site from all of these sources and, where feasible, provide recommendations for mitigation measures to alleviate the impact of flooding on a site and its surrounding area.
An FRA is generally required to be submitted as part of a planning application for all potential site developments proposed in designated flood zones.
When are Flood Risk Assessments Needed
To satisfy national planning policies, if you are planning a development within a flood zone, you will be required to undertake a Flood Risk Assessment (FRA). Requirements for an FRA differ between Scotland, England, and Wales where planning matters are devolved.
A Flood Risk Assessment in England is required when:
- In flood zone 2 or 3, including minor developments and changes of use.
- More than 1 hectare (ha) in flood zone 1.
- Less than 1 ha in flood zone 1, including a change of use in development type to a more vulnerable class (for example, from commercial to residential), where they could be affected by sources of flooding other than rivers and the sea (for example, surface water drains, reservoirs).
- In an area within flood zone 1 with critical drainage problems (as notified by the EA and local authorities).
Factors that can influence flooding?
Flooding can be influenced by various factors including:
- Surface water run-off
- Proximity to rivers and coasts
- Current land usage
- Local topography
- Vegetation cover
- Existing drainage
- Hardstanding
- Groundwater
- Rainfall levels
- Quarries
- Geology
- Mines
Outline Drainage Design Strategy?
Often, one of the most important requirements of a Planning Application is to ensure (and be able to demonstrate) that the proposed development will not lead to an increase in flood risk elsewhere.
In this situation, an Outline Drainage Strategy is likely to be requested by the Local Planning Authority.
This can include sites which are not located in a floodplain (river or coastal).
It is requested to ensure that subsequent run-off from the proposed development will be mitigated.
RPM Water Management has extensive experience with drainage outline drainage strategies forming a major part in flood risk assessments.
Our team of highly qualified and experienced engineers can deliver outline and detailed design strategies for all types of development. Both outline and detailed design will cover foul and surface water drainage detail with each site having its own specific and often challenging site characteristics to overcome.
Outlines strategies often form part of a Flood Risk Assessment or form standalone reports to support a planning application. Here many of the site characteristics are considered such as how surface water, usually caused by rain, affects a site and the surrounding area. It establishes how water behaves on a site, and determines the runoff rate, flow pathways, connectivity to exiting sewers, watercourses and infiltration potential.
It then investigates what effect the development will have on these things, and outlines measures the developer can take so that runoff rates meet the requirements for the site set by national and local planning policy.
Sustainable Drainage – Detailed Drainage Design
- An assessment of suitability for infiltration based on soil types and geology.
- Evidence of infiltration tests, particularly at the location of any intended infiltration device, and groundwater level monitoring is also required.
- A Detailed SuDS Design Statement,
- A Method Statement detailing how surface water arising during construction will be handled.
- Confirmation of land ownership of all land required for drainage and relevant permissions.
- A SuDS Management Plan.
- Foul drainage proposals.
- Where required for major developments or phasing of minor developments a plan showing each development plot (e.g. a development block of houses) which shows the allocation of volume storage and discharge rate given to that plot as part of a wider SuDS strategy.
The following applications are not considered to have a significant impact on the sites surface water drainage Therefore the Lead Local Flood Authority will not be providing bespoke comments unless the site sits within a Critical Drainage Area (CDA), as defined in the Surface Water Management Plans (SWMPs).
- Minerals extraction
- Greenfield development that doesn’t increase impermeable land by more than 0.5ha
- Brownfield development that doesn’t increase the impermeable land by more than 0.1ha
Hydraulic Modelling
- Flood Mapping
- Flood contouring
- Flood plain compensation schemes
- River Realignment
- Bridge and Culvert Crossings
- Design of Ponds and other Landscape Features
- Flood Levels Assessment of river levels
- Land Acquisition Studies
- Flood map challenge
This is carried out to check the veracity of the flood mapping used by the authorities. It is usually considered when the client has local knowledge which leads the client to requiring the mapping to be challenged based on local knowledge that this is wrong. In these cases, because of the expense, we operate a staged approach.
Firstly we ask the relevant authority to send us their flooding modelling and data upon which this is based in order to check it for its veracity. We then report back to the client on our findings.
If, as a result of that, the client wishes us to go further then we basically strip down the modelling by computerisation and check its detail and accuracy. A further report is then sent to the client on our findings and recommendations.
Property Level Flood Protection
Environmental Assessments
- Environmental Impact Assessments
- Non-Statutory Environmental Assessment
- Water Quality Monitoring
- Soil Quality Monitoring
- Biodiversity Monitoring
- River Restoration
- Habitat Creation/ Renovation
As environmental specialists, we can offer a variety of environmental surveys and assessments for our clients. These environmental assessments can be used to obtain planning permission where environmental concerns have been cited, reduce the costs associated with rejected planning applications, and gain environmental credits towards BREEAM certification.
Our industry experience has given us an in-depth knowledge of national and regional policies, as well as nature conservation legislation relating to all areas of development. Combined with our state-of-the-art survey data, our environmental assessments are industry leading in both speed and accuracy.
The environmental assessments and surveys we offer:
- Flood Risk Assessments
- Drainage and SuDS
- Civil Engineering
