Rapid Assessment for Resilient Recovery and ... - GFDRR

How to Strengthen the Ring’s Dike – Industrial Estates
o The total dike length around the 7 industrial estates is about 200 km.
o Typical height of the dikes is 2–3 meters, steep slopes 1:2 – 1:3, typical crest width
1–2 m; typical footprint is 10–15 m.
o Inundation depth at estates was 1.5–3 meters, for example at Rojana/High Tech.
o Tentative estimates of the return period of this event are in the order of 1/50 – 1/100
year.
Some dikes were raised just before the flooding to prevent the areas from flooding (which in the
end happened due to breaches in the dikes at some locations and also overflow at low spots).
This raise was carried out with material just next to the dikes (poor quality). These dikes need a
substantial re-design/re-construction since most of the material being used was not appropriate
for levee construction.
Tentative cost: THB 15 billion (for a protection of 1/100 year flood)
The required level of protection depends on measures upstream/along the Chao Phraya River
Basin. If the dikes along the river system are strengthened/raised, then the industrial estates
could have lower dikes for the same level of protection and vice versa. Another thing which
may form part of the solution is the inclusion of temporary flood defenses (e.g. sand bags but
also other temporary flood defense systems). If the option is being considered to raise the dikes
around the estates north of Bangkok substantially to get, say, a 100-year level of protection,
thorough analysis of the entire river basin should be part of the initial assessment.
It is also important that the government study how to protect the homes of the employees of
these estates.
Institutional and Policy Recommendations
All recommendations for institutional and policy recommendations are bound up in
reviewing and passing through parliament the new water bill. This would institutionalize
and strengthen the integrated water resources management approach and produce the
most strategic and holistic changes for the sector. Specific recommendations for consideration
in this review include:
• Establish an effective river basin model that follows best practice and
institutionalizes the River Basin Organization structure for each main and
sub-basin.This model would provide a basis for all modeling, water resources
management activities and related development activities in the basin.
• Appoint a high-level “champion” for water management to bring all
stakeholders together and move the existing water basin authority to a central
position under the champion.
• Accelerate the implementation of the Royal Initiative for Flood Management
considering social impacts and land use compensation
84 THAI FLOOD 2011 RAPID ASSESSMENT FOR RESILIENT RECOVERY AND RECONSTRUCTION PLANNING