Strategic Flood Assessment for the World Bank in Nigeria

www.ambiental.co.uk | info@ambiental.co.ukShaping Flood Modelling Decisions Globally

Bringing peace of mind to Ibadan communities

In response to devastating floods in 2011, the World Bank commissioned Ambiental to carry out an urgent, strategic flood risk assessment for the city of Ibadan in Nigeria. We were tasked with developing a long term flood risk management plan to ensure the future security and safety for large sectors of the communities which currently suffer regular and damaging flooding.

As a fundamental part of the study, Ambiental developed a city-wide numerical flood model allowing simulation of a range of return periods and future scenarios. This helped quantify the level of current and future risk, and scientifically assess the benefit of a range of mitigation options.

Key Outcomes 3 Saving lives 3 Reducing cost of flood damage 3 Enabling better decision-making 3 Increasing recovery rate following floods

3 Providing peace-of-mind and security 3 Improving overall quality of life. 3 Improved and continued economic growth

Ibadan, Nigeria context and problem at a glance

Situation• City of Ibadan, Nigeria

(population ~ 5m) • Frequent flash flooding• In 2011 over 100 people killed

and multi million dollar damage during 1 in 10 year flood event

Problems• Uncoordinated urban growth• Poor urban drainage• Complex river networks• Risk from reservoirs• Frequent flash flood incidence • Vulnerable communities living

in areas of high risk.• Lack of awareness of flood risk• No means of warning public of

impending floods• Piece-meal approach to

managing flood risk within local government

This was one of the most rewarding projects we’ve undertaken in Africa.

“ “

Scott FergusonTechnical Director – Flood Risk Management, Ambiental

info@ambiental.co.uk www.ambiental.co.uk

UK Head Office +44 (0)1273 704 441

Asia/Australasia +61 (0)420 834 080

The Sussex Innovation Centre, Science Park Square, Brighton, BN1 9SB, UK

Overall solution and recommendations provided by Ambiental• Identified and co-ordinated requirements for urgent repair work on a large

dam and associated reservoir just upstream of the city.

• Identification and design of priority works to be carried out on the many bridges and river crossings damaged during recent flood events.

• Recommendations regarding flood mitigation through a wide range of structural and non-structural capital schemes and investments for improved drainage and flood protection throughout the city. These were designed to be both sustainable and cost effective, ensuring ongoing environmental, social and economic benefits.

• Design and Implementation of a flood forecasting and warning system, coupled with planning, preparation and improved emergency response. Our fully integrated technical solution included:• 1D/2D city scale urban drainage model with simple visual displays

and animations of forecast flooding,• Latest X Band Doppler weather radar technology providing real-time

rainfall input,• Pre-defined warning threshold with automated alarm trigger and

event management,• The latest technology to provide accurate and timely flood warnings,

training, planning and preparation in order to better respond to impending flood events,

• Public education / awareness raising to increase responsiveness and agility of emergency services, safeguarding lives and property.

Ambiental offer a wide range of strategic flood consultancy, flood planning and global flood models. For more information, or to discuss your specific requirements, simply contact Ambiental in your region.

Strategic Flood Consultancy & Global Flood Models