Rapid Assessment for Resilient Recovery and ... - GFDRR

water intake structures (THB 28 million) and water treatment plants (THB 31 million) in
urban areas. Almost all damage in the sanitation sub-sector occurred in connection with
urban wastewater treatment plants (THB 1.6 billion). For the purpose of this analysis,
individual household septic tanks and related damage and losses are included in the
housing sector, impacts of water quality on public health such as increased prevalence of
water-borne diseases are calculated under the health sector, and impacts on environmental
pollution through wastewater is included in the environment sector.
In the rural water supply sector, damage is estimated at approximately THB 1.8 billion. The
reason for this relatively high value of damage compared to urban water supply is the
almost exclusive reliance on wells or small-scale surface water supply systems (65 percent
of which are groundwater wells and 35 percent surface water sources). Whereas some of
this damage refers to damaged pumps or other control panels, some wells were damaged
to such an extent that they needed to be shut down and replaced with new wells 85 . An
example of types of damage is given in Table 27. Due to a lack of further data, estimations
from damage and losses in two provinces (Nakhon Sawan and Chai Nat) were extrapolated
to other flood-affected provinces.
For urban water supply, damage is estimated at THB 70 million. This assessment is
based on information received by the Provincial Waterworks Authority at central level,
the Metropolitan Waterworks Authority for Bangkok metropolitan area and observations
made during field visits to Nakhon Sawan province as well as the largest MWA facility in
Lak Si district of Bangkok. For public or private municipality-run water supply systems, no
actual information on damage or losses was available at the time of the assessment at a
central authority 86 . In order to include an estimation of the damage and losses incurred,
the following estimate served as basis: 75 percent of urban water schemes outside the
Bangkok metropolitan area are managed by the PWA, whereas 25 percent are managed
by the municipalities (or respective private operators). The amount of damage and losses
incurred per province was then calculated as an additional 33 percent of those estimated
for PWA-run systems.
Due to sufficient prior warning and preparation time, MWA managed to protect all four
Bangkok-based water treatment facilities 87 from major flood impacts. The October –
November 2011 floods in Thailand reached the largest of the four facilities in Bangkok in
mid-October. The last time the MWA had to prepare for a serious flood was in 1995; the
2011 floods are assessed as much more extensive.
85 About 35 percent of the wells were completely broken and need to be replaced. The cost of replacing these wells represents
about 80 percent of the total cost of repair.
86 The number of municipalities within the affected provinces is not quite clear, but estimated to be at least several dozen.
During the assessment, the team did not receive information by any central government agency on damage and losses
among these municipalities. It was also not possible to contact each individual municipality for data.
87 The water treatment plants (WTP) in Bangkok (all MWA managed) are: 1) Bangkhen WTP, with a maximum capacity of
3.6 m3 per day; 2) Samsen WTP, 550,000 m3/day; 3) Thonburi WTP, 170,000 m3/day; 4) Mahasawat WTP, 1.2 m3/day.
THAI FLOOD 2011 RAPID ASSESSMENT FOR RESILIENT RECOVERY AND RECONSTRUCTION PLANNING
89