Flood Management Systems

Two Phase Process:

1. Non – Structural

2. Structural

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Cork City 2009Joe Byrne - DT117 March 2010

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Causes of flooding

Removal of ecosystems i.e. forestry and wetlands

Alteration of the natural environment of rivers

Development on flood plains – Poor Planning

= Lack of natural resistance to flooding

Non - Structural 1990’s the E.U published ‘Best Practices on Flood Prevention,

Protection and Mitigation Directive

In Ireland Office of Public Works (OPW) was given the responsibility to implement its requirements;

1. Undertake a preliminary flood risk assessment

2. Prepare flood hazard and flood risk maps

3. Establish flood risk management plans.

Move away from structural flood defence barriers to a more risk management

Flood Maps & Warning System• Catchment Flood Risk

and Mgt Study (CFRAMS)

– Strategy to manage flood risk

+

• Flood Mapping

– X-section Thru River

– Survey + Maths equation = water levels

Warning System

– Level sensor warns of

high water levels

Combination = Flood Mgt Strategy

Structural Flood Mgt Systems Sustainable Urban Drainage Systems (SUDS) -

strategy for Flood prevention

1. Stormwater Attenuation Tank

2. Filter strips and swales

3. Permeable surfaces and filter drains

4. Basins and ponds

Domestic / Commercial flood barrier - Self Closing Flood barrier

1. Stormwater Attenuation Tank

• Retain water during peak

storm levels

• Hydro Break MH allows

5 litres/sec/acre approx.

into watercourse

2. Filter strips and swales

Vegetated features which are used to drain water from impermeable areas.

Slows rate of water into watercourses

3. Permeable surfaces and filter drains Areas which have a

volume of permeable material below ground to store water.

Permeable surface can consist of grass, gravel, porous paving etc

Slows rate of water into watercourses

4. Basins and Ponds

Basin

Pond

Takes runoff water during storm periods and are free from water during dry weather conditions

Contain water during dry periods and are designed to hold more when it rains.

Self Closing Flood barrier

Dutch design used to protect premises against flooding

The flood defence device rises from the ground level up to 1m high and lengths of 100m to 1000m

SECTION

Conclusion – Sustainable Flood Mgt