Flood risk assessments for Kingston upon Thames planning applications
Kingston's Validation Local List (February 2024) asks for a flood risk assessment on proposals in Flood Zone 2 or 3 or in an area of mapped surface water flood risk, and the council's flood guidance asks for a site-specific one for all development in Kingston Town Centre. We write it for a fixed £395, with the topographical survey and floor levels the list expects drawn in.
Fixed fee from £395 · all prices
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What Kingston's Validation Local List says
The council's Validation Local List (February 2024) asks for a flood risk assessment on all applications other than householder applications on sites of 1 hectare or greater in Flood Zone 1, and for all proposals located in Flood Zone 2 or 3 or subject to Surface Water Flood Risk as designated by the Environment Agency. For the avoidance of doubt, it says a site is in a flood zone if any part of the site within the red line is in that zone.
That red line rule catches owners whose house sits just outside a zone but whose back garden does not. We check the whole site boundary, not only the front door.
Flood Risk Assessments in Kingston upon Thames
from £395
Every price is the full fixed fee you pay. No VAT is charged. Council application fees are paid to the council separately.
What you get
- Your address checked for flood zone and surface water flood risk
- A site-specific assessment to Kingston's Validation Local List
- Floor levels and mitigation shown on your plans, as the list requires
- A topographical survey brief where the list asks for contours
- A basement check against the council's access and threshold rules
- The assessment as a PDF for the planning application
- Flood zone and surface water
Zone 2 or 3, or mapped surface water risk, from the flood map for planning.
- Householder or other
A householder application uses the standard Environment Agency form instead.
- Survey and levels
A topographical survey with contours, and permeable and impermeable areas.
- Write the assessment
Sources of flooding, climate change, tests and an escape plan if needed.
- Build mitigation into plans
Finished floor levels and other measures drawn on the submitted set.
Householder applications use a form
For a householder application in Flood Zone 2 or 3 or at surface water risk, the same list asks that the assessment be provided on the "standard environment agency form". That is a lighter document than a full report, and for a simple scheme you may be able to complete it yourself.
We would tell you so. If the scheme goes beyond a householder application, such as new flats, a change of use or a basement beside a watercourse, the full site-specific assessment applies and that is what the fixed fee covers.
It says basements should not be permitted in Flood Zone 3b, basement dwellings should not be permitted in Flood Zone 3a, and self-contained basement dwellings and bedrooms are not permitted in Flood Zone 2.
A survey, contours and an escape plan
Kingston's list names the drawings behind the report. The assessment should be accompanied by a topographical survey of the existing and proposed sites, with contours demonstrating the flow of surface water across the site, and details of permeable and impermeable land. Mitigation proposed in the assessment, such as finished floor levels and living roofs, must be incorporated in the plans.
Where a safe and dry means of escape cannot be provided, the list says a Flood Evacuation Management Plan will also be necessary, setting out how the building operates safely in a flood. Because we also produce the drawings, the levels in the report and on the plans are set together.
Kingston Town Centre
The council's flood risk assessment guidance says a site-specific flood risk assessment is required for all developments within the Kingston Town Centre area. If you are converting or extending a building near the river in the centre, do not assume your address needs nothing because the flood map looks quiet. The guidance was written in May 2021, so we confirm it against the current Local Plan when we start.
Basements in Kingston
The same guidance says all basement rooms must have internal access and egress to a higher floor above the design flood level, and that basements, lightwells and vents must have access thresholds raised 300mm above the 1 in 100 year plus climate change flood level. It says basements should not be permitted in Flood Zone 3b, basement dwellings should not be permitted in Flood Zone 3a, and self-contained basement dwellings and bedrooms are not permitted in Flood Zone 2.
If you are weighing a basement, those rules can decide whether it is worth drawing at all. Our basement conversion drawings are prepared with that test in mind, and a Basement Impact Assessment signed by a chartered engineer is a separate requirement on the same list.
Fee and next step
The fixed fee is £395, the total you pay, and no VAT is charged. It covers the flood map check, the site-specific assessment and a drainage note for a house, extension or small conversion. The assessment with a SuDS drainage statement is £625. A topographical survey and any specialist modelling are quoted separately. Send the address and what you want to build.
Sources
Every figure on this page, where it comes from and a link to the original.
| Figure | Source | Link |
|---|---|---|
| Surface Water Flood Risk | Kingston Validation Local List (February 2024), Flood Risk Assessment (source wording: "All applications, other than Housholder applications, on sites of 1 hectare or greater in Flood Zone 1 and for all proposals located in Flood Zone 2 or 3 or subject to Surface Water Flood Risk as designated by the Environment Agency.") | www.kingston.gov.uk |
| any part of the site | Kingston Validation Local List (February 2024), Flood Risk Assessment (source wording: "a site is considered to be in a particular flood zone if any part of the site (as identified by the red line area) is situated within that Zone") | www.kingston.gov.uk |
| standard environment agency form | Kingston Validation Local List (February 2024), Flood Risk Assessment Form, for householder applications in Flood Zone 2 or 3 or at surface water risk (source wording: "The Flood Risk Assessment should be provided on the standard environment agency form.") | www.kingston.gov.uk |
| topographical survey | Kingston Validation Local List (February 2024), Flood Risk Assessment (source wording: "Topographical survey of the existing and proposed sites, with contours demonstrating the flow of surface water across the site.") | www.kingston.gov.uk |
| Flood Evacuation Management Plan | Kingston Validation Local List (February 2024), Flood Risk Assessment (source wording: "Where a safe and dry means of escape cannot be provided a Flood Evacuation Management Plan will also be necessary") | www.kingston.gov.uk |
| Kingston Town Centre | Kingston Strategic Flood Risk Assessment, Flood risk assessment guidance part one (written May 2021) (source wording: "A site-specific FRA is required for all developments within Kingston Town Centre area") | www.kingston.gov.uk |
| internal access and egress | Kingston Strategic Flood Risk Assessment, Flood risk assessment guidance part one (written May 2021) (source wording: "All basement rooms must have internal access and egress to a higher floor above the design flood level") | www.kingston.gov.uk |
| 300mm | Kingston Strategic Flood Risk Assessment, Flood risk assessment guidance part one (written May 2021) (source wording: "must have access thresholds raised 300mm above the 1 in 100 year plus an appropriate climate change allowance flood level") | www.kingston.gov.uk |
| self-contained basement dwellings and bedrooms are not permitted in Flood Zone 2 | Kingston Strategic Flood Risk Assessment, Flood risk assessment guidance part one (written May 2021) (source wording: "Self-contained basement dwellings and bedrooms are not permitted in Flood Zone 2.") | www.kingston.gov.uk |
The full guide lives on our sister site
We still prepare this for a fixed £395. The detailed guide to it is on fixedfeeplans.co.uk, part of the same practice.
Questions people ask
Does a Kingston householder application need a flood risk assessment?
My house is outside the flood zone but my garden is inside. What counts?
Do I need a survey?
Can I have a bedroom in a basement in Flood Zone 2?
Will the assessment secure permission?
Photographs: James Emmans (CC BY-SA 2.0).
