Every year flood converges firstly to the Northern districts in Dong Thap Muoi, starting from the beginning or mid August and lasting to November. In this time, the rain has the biggest flow and intensity, causing difficulties for production and life. Flood in Long An province is slow and its level is not deep as upstream but it lasts for longer time.
The
frequency of high flood tended to reduce from 1 time for 8 - 10 years
in the past, to 1 time for 3 - 4 years (1961, 1966, 1978, 1984, 1991)
and high flood had occured for 3 consecutive years (1994, 1995, 1996),
especially, flood was very high in 2000.
- Flooding levels according to the natural area in 1996 were as follows:
+ Below 50 cm with flooded area of 50.294 ha, accounting for 13,2 % of the natural area.
+ From 50 - 100 cm with flooded area of 72.360 ha, accounting for 18,99% of the natural area.
+ From 100 -150 cm with flooded area of 63.830 ha, accounting for 16,75% of the natural area.
+ From 150 - 200 cm with flooded area of 94.840 ha, accounting for 24,88% of the natural area.
+ From 200 - 250 cm with flooded area of 66.720 ha, accounting for 17,50% of the natural area.
+ Over 250 cm with flooded area of 33.070 ha, accounting for 8,68% of the natural area.
- Flooding duration:
+ Less than 3 months with 305.757 ha, accounting for 69,91% of the natural area.
+ From 3 - 5 months with 64.724 ha, accounting for 30,09 % of the natural area.
Especially, flood of the year 2000 was the biggest in decades and the
long flooding period caused great damages to production and life of
people. The highest water level in Moc Hoa (Long An) was 3,27 meter, 41
cm higher than flood peak in 1978. Flood run strongly to the South,
resonating with hurricane tide, causing deep and wide flooding in
300.000 ha of natural area, including 132/188 communes, equivalent to
12/14 districts of province. The average flood was from 1,5 - 2 meters,
some regions had deep flood of over 3 meters. Total damages to property
were about 650 billion dong.
At present, the province has co-ordinated with flood control programs of
the Central level to build sewer and dyke system to control closely and
effectively flood, i.e. with small flood, try to keep water, with high
flood, use for washing alum to transform the land. Invest in building
186 residential clusters to ensure the stable and sustainable life in
flood season. In construction, should choose the elevation exceeding the
flooding level of the year 200