1.4. Floods

According to the UN, the number of people at risk from floods is projected to rise from 1.2 billion today to around 1.6 billion in 2050 (nearly 20% of the world’s population). [Ref 25]

Floods are natural events that occur along streams over periods varying from several times a year to every few years. However, urbanization of floodplains and manipulation of streams and rivers has increased both the magnitude and frequency of floods in many areas. [Ref 26]

Floods can occur suddenly and recede quickly or take days or even months to build and discharge. While natural floods often occur regularly in the same season, human-induced floods tend to occur at irregular intervals and vary in size, duration and the affected area.

A flood occurs when a stream or river is incapable of containing the discharge. Contributing factors to this condition are heavy rains, rapid snowmelt, steep slopes, dam failure, storm surges, and human manipulation of the landscape, such as deforestation. Heavy rains and rapid melting of snow cover are the most common causes of flooding.

When heavy rainfall lands on slopes that have little vegetation, the water runs off immediately, filling stream channels. This runoff causes erosion and bank collapse, and the overflow spreads across the land as a sheet flow. Flooding is even more serious if the area is bordered by steep slopes because steepness increases the flow velocity.

Urban floods occur when heavy rain is not drained quickly into the ground due to pavement in cities and the sewage system being unable to cope with the amount of water. According to the EEA, cities with more than three quarters of their surface area sealed, such as Paris, Thessaloniki, Bucharest and Barcelona, face the risk that water cannot be absorbed quickly into the ground during heavy rainfall. [Ref 27]

SAI Bulgaria conducted an audit on the development of plans for managing flood risk.

AUDIT CASE 

SAI of Bulgaria audited issues related to the established conditions for the successful implementation of the procedure and effectiveness in the implementation of activities in developing plans to manage flood risk.

The audit relied on Directive 2007/60 / EC and analysed the implementation of long-term planning to reduce flood risks in three stages: a preliminary assessment of flood risk, threat and risk maps, and plans for managing flood risk.

The audit concluded that the procedure is in full correspondence with the European and national policy in the environment area and should contribute to achieving the criteria set in the ‘Environment’ OP. Verification of costs and payments for expenses were generally effective except for a couple of instances of delays in processing payment claims. Too much delay creates the risk that the ministry will have to use funds from its own budget instead of OP funds to cover expenses.

The personnel involved was mostly sufficient in number and in qualifications. In some cases, negative effects on implementation was the result of the lack of experts in public procurements, lack of experts in dealing with EU funding, and frequent changes in directors of the basin directorates.

However, the progress was not fully satisfactory. Some major project activities had not been completed such as developing risk plans for river floods as well as development of digital mapping models of water basins.