Flood Risk Report

Chartered Town Planner
5 Polwithen Road
Penzance
Cornwall TR18 4JS

Tel.: 01736 369874
Email:  HYPERLINK "mailto:jonpender@hotmail.co.uk"
jonpender@hotmail.co.uk


LAND S.E. OF UNIT 24, MARSH LANE INDUSTRIAL ESTATE,
HAYLE TR27 5JR

CONSTRUCTION OF AN INDUSTRIAL BUILDING

M S and D Ltd

CORNWALL COUNCIL ref. PA19/06344

FLOOD RISK ASSESSMENT

August 2019

INTRODUCTION

This document has been prepared by Jon Pender, Chartered Town Planner, for M S and D Ltd for their sole use in relation to land south-east of Unit 24, Marsh Lane Industrial Estate, Hayle TR27 5JR. No responsibility is accepted for liability arising to any third party from the unauthorised use of this material.

THE SITE AND ITS SURROUNDINGS

The application site is on the eastern side of the Marsh Lane Industrial Estate, at the end of its adopted cul-de-sac road. The Estate covers an area of over 5 hectares on the eastern edge of the town of Hayle, bounded by the Hayle rugby ground on the west and Marsh Lane on the north, with the A30 trunk road some 150 metres to the west. The Estate was developed from 1990 (see planning application ref. W1/90/P/0843 for laying it out, submitted by the former Penwith DC) and a 2005 aerial photograph on Cornwall Council’s Interactive Map shows that just over half of it was then developed by a range of commercial buildings and uses.

The application site has an area of about 0.2 hectares, and is one of only two parts of the Estate remaining undeveloped. The site and the rest of the Estate are not subject to any landscape designations and are not liable to flood.

THE APPLICATION

Full permission is sought to erect a standardised industrial building similar to many others on the Estate. It measures 29.8 metres by 10 metres and 6 metres to its roof ridge and will be built in the southern part of the site, with a parking and turning area between it and the end of the Estate road.

POLICY BACKGROUND

The main, national policy document for Flood Risk Assessments [FRAs] is in paragraphs 155 to 165 of the Government’s National Planning Policy Framework [NPPF] (February 2019), supplemented by the companion Technical Guidance published in March 2012.

The Environment Agency’s Flood Map for the area of the application site shows that, like the rest of the Estate, it is outside Flood Zones 2 and 3. It is therefore in Zone 1. National planning guidance in respect of flooding says that all uses of land are acceptable in this Zone where FRAs are not normally required for proposals on the small scale put forward in the application.

The application needs a FRA only because the Environment Agency’s May 2015 document indicates there may be drainage problems in a Critical Drainage Area [CDA] identified on a 1:20,000 scale plan - the site just inside its north-eastern boundary.

ASSESSMENT

The proposal is assessed as follows against all possible flooding mechanisms, as advised in paragraph 6 of the NPPF’s Technical Guidance.

Rivers

The nearest watercourse to the application site is a small stream running westwards to the sea over 0.2 kilometres to the north. The Environment Agency’s Flood Map shows the application site to be outside its flood plain and the site is higher than and distant from the likely extent of any flooding along this minor watercourse. Therefore, there is no risk of fluvial flooding affecting the site.

Sea

The application site lies over 1 kilometre from the coast and at an elevation of 30 metres AOD. Sea levels are currently estimated to be increasing in the order of 1 metre in 100 years. The proposed development is consequently well outside any areas of current or anticipated tidal flooding.

Groundwater and the land

The application site is not close to the nearest watercourse. The topography in this locality means that the application site is on land sloping northwards. The land uphill of the site is mostly undeveloped and so capable of absorbing rainfall. There is no history of flooding from this source.
Sewers, reservoirs, canals and other artificial sources
There are no such potential flood mechanisms near and uphill of the application site.

LIKELIHOOD OF FLOODING AS A RESULT OF THE PROPOSAL

The site is currently undeveloped and disused, but clearly part of an industrial estate promoted by the Local Authority and established over the last 30 years. The current application will bring the Estate near to completion. There have been no flooding objections to any of the long series of previous planning applications to construct similar commercial buildings on the rest of the Estate.

The proposed building has a “footprint” of almost 300 square metres. However, the majority of the application site will stay undeveloped so that there is ample space on-site to dispose of surface water runoff. The application includes a parking and turning area but it will be surfaced with a non-permeable material so that it will not affect the current absorption of rainwater directly into the ground.

As a result, the current application will not alter the present pattern and volume of surface water run-off.

The slope of the land at the application site means that it will avoid inundation from any shallow overland flooding that might conceivably occur at times of extreme rainfall, whose frequency is expected to rise because of climate change.

Consequently, the proposal will have no flooding impact on sites downstream.

CONCLUSION

The application site is in Flood Zone 1 and is not at risk of flooding from any source. As far as the CDA designation of Hayle is concerned, additional surface water runoff from the proposed building can be disposed of on-site. It follows that there is no risk of significant flooding downstream as a result of the current amended proposal.

In conclusion, the present application is acceptable with respect to flood risk and so satisfies CLP policy 26 as well as the NPPF and its companion Technical Guidance.


via http://planning.cornwall.gov.uk/online-applications/files/04B3585C867261...