For Stage 1 the number of people affected varies from 3,000 for the flexible option. For Stage 1 the amount of land acquisition required is about 95 ha for the flexible line. People affected will either need to be resettled or will continue to be vulnerable to flooding. Estimates for Stage 2 have not been completed.
Estimates have not been made in this way. This will determine after completion of inventory and socio-economic survey planned to be implemented through a consultancy team from University of Colombo
It will be decided when preparation of RAP together with all stakeholders including affected people
It will decide at the finalization stage of RAP in consultation of stakeholders and affected people
It will adopt all possible means and ways to find special scheme for this project to offer more attractive compensation package
Concrete walls can be constructed in smaller spaces, and therefore fewer people would be affected. They are somewhat more difficult to construct and unfamiliar to Sri Lanka, so may require international contractors for designing and construction.
Earthen embankments need a much larger land area (more than 3 times as much) and so more people are affected. They are simpler to construct and are well known in Sri Lanka, so local construction contractors can do them.
It has been agreed by both World Bank and Asian Infrastructure Investment Bank (AIIB) to cofounding for CRIP II.
The embankments are only possible in areas where a 50 foot space is available and about 30% of the total length is fall in to flexible.
The concrete wall type is mainly for the flexible line very much closer to the river banks.
Not in detail at this time, it will cover under detail designing stage. However, all local floods, drainage etc, will be managed with a combination of embankments, gates and pump houses constructed in the surrounding areas where necessary. The detailed design will try to minimize pump use where possible.
With an average annual expected damage of LKR 7,800 million, this would be approximately the level of damage annually if the project does not go ahead.
Project is planned to launch a comprehensive communication campaign to provide all information on proposed project, educate people and, communicate various stakeholders, political authority, government officials, private sector people and people in the target area.
National and district level awareness programme are conducted by the Project Management Officer and divisional and village level awareness programme will be conducted by a team of consultant deployed by University of Colombo.
The EIA will be completed by hiring a consultancy team and they will identify mitigation options.
1) Flood embankments from Hanwella to the river mouth, with gates and pumps where necessary for protection and draining of tributaries.
Embankment will establish as flexible line in between 0 to 50 m stretch of river ban depending on available space, this embankment will protect people and properties from 1:50 return period.
2) Upper basin reservoirs to capture flood waters from the upper basin and raise the total level of protection to 1:100 year return period
1) Detailed hydro-logical analysis
2) Cross sectional surveys
3) Flood modelling based on two types of flood model
Counterpart staff (staff of Irrigation Department and Sri Lanka Mahaweli Authority)
Many options were considered, both structural and non-structural
A 1:50 year event is one that would happen once every 50 years on average. A 1:100 year event, is one that would happen once every 100 years on average. However, as this is a statistical definition, such an event could happen at any time.
No. For the period of time that only embankments are protecting your house and land (prior to construction of the reservoirs) if a flood event higher than 50 years return period occurs there will be flooding. Similarly, once reservoirs are constructed, it is possible that a flood event greater than a 1:100 year return period can occur. However, in both cases, the extent of flooding and amount of damage to homes and land will be less than without the flood protection.
It is necessary to construct both the embankments and the reservoirs because neither can protect to the 1:100 year return period on their own. Constructing embankments take much less time than constructing reservoirs, so having two stages allows a good level of protection fairly quickly.
No, it is not. 1) reservoirs are not of sufficient volume to have an impact, 2) the CEB reservoirs cannot be drawn down (water levels) quickly enough in the event of a flood forecast.
The positive impact of the construction of new upstream reservoirs and flood embankments will be protection from all flood events up to the 1:100 year return period. In addition the reservoirs will be developed as multi-purpose, being able to enhance water resources for interbasin transfers to dry zone basins, bulk water supply for domestic and industrial water, hydropower generation.
Yes. It raises flood levels and this has been factored into the embankment heights.
Yes. There is no impact
No. It is too far away for impact.
These issues have been studied to find solutions
Details will be worked out at detail design preparation stage.
Yes. It has become evident that this is not an issue.
Yes, this is part of Stage 2.
Yes. The land use management of the upper basin is reasonably good and therefore not a significant factor in flooding.
The ‘minor flood protection works’ will be incorporated into the design of the Kelani Flood Mitigation Strategy and will no longer be “minor’.
Implementation of Stage 1 could start as early as the end of 2018. Construction could be completed as early as end of 2021. Implementation of Stage 2 could start as early as and of 2019. Construction could be completed as early as 2025.
Stage 1 costs range between LKR 37,060 to LKR 42,670 million for the flexible line. These costs are a combination of construction and land acquisition and compensation.
Stage 2 costs have not been determined. Stage 2 is being analysed now.
For Stage 1:
flexible line: LKR 42,670 million, benefit LKR 7,800 million, EIRR 19%
For Stage 2: not yet determined
During construction the embankments will be protected with geotextiles and other forms.
For larger return period events there will be areas of the embankment designed to be slightly lower as overflow sections.
Not at all, all the operation, regulation and maintenance will be done by the ID. However, requirement for computerized system for integrated reservoir operation and flood management is currently discussing.
Do not allow people to settle or resettle in the unprotected areas through new legislation and O&M standing orders.