Abstract:
The estimation of residential water demand is the essential
part for water supply management and planning. Currently,
the Metropolitan Waterworks Authority (MWA) applies the
average water demand of 250 l/cap/day for the planning and
design. This value is inaccurate from the actual water use
behavior of the population, which is a result of various factors
such as income status, living conditions, housing characteristics
and land use. etc. Thus, this study assesses MWA water
demand of residential water users (M1) by analyzing the water
consumption data based on the 7-year recoded water user
database (2012-2018). The estimation has been classified by
area / district, with the concerns of the numbers of registered
population, property (vertical / horizontal) and the latent
populations in the form of service business labor in 62 areas
(50 in Bangkok, 6 in Samut Prakan and 6 in Nonthaburi).
The residential users is divided into 6 groups, which are
Group.1 : the old town area, Group.2 : business areas and
vertical accommodations, Group.3 : small horizontal residential
areas, Group.4 : medium-sized residential areas, Group.5 : largesized
low-rise residential areas and Group.6 : industrial areas.
The results show that the average water consumption rate of
the residential groups of MWA is 125-263 l/cap/day; in which
the lowest and highest water demands are found in Group.1
and Group.5, respectively. In addition, Group.3 : a small
horizontal residential area which covers Khlong Sam Wa, Bang
Yai and Bang Bua Thong districts has the greatest growth rate
of the water user. This may affect the excess of future water
demand that MWA had previously predicted. The results of the
analysis of sub-spatial water usage behavior which are in line
with the urban development model will support the water
management planning for consumption to be more accurate.