IMPACT OF URBAN EXPANSION ON WATER DEMAND The case study of Nakhonrachasima city, Lam Ta Kong Watershed

Abstract

This research analyzes the urban expansion of Nakhonrachasima City, the regional center
of Northeastern Thailand, in terms of water demand and water usage in the Lam Ta
Kong Watershed. Lam Ta Kong Watershed has had a severe water shortage problem for a long
time. Nakhonrachasima City is a small city with 172,387 persons. The results show that the
urbanization effect on changing land use rapidly and increases water consumption. The trend
of the water consumption rate in Nakhonrachasima increases at a high rate. Presently, water
consumption in the city is 64,336 cu m/d and the water consumption rate is 358 lcd, which is
high when compared with the standard water supply design of Thailand. In terms of urban
expansion, the agricultural area decreases by 2.76 sq km/yr on average and may soon be spent.
The population decreases while the water usage tent to increases. Moreover, the urbanization
also affects water usage in the city. The water consumption level per person in Nakhonrachasima
City in 2024 was 513 lcd, which was a very high rate, 1.48 times higher than the standard water
supply design of Thailand. Although the current water usage of Nakhonrachasima City is only
22.16 % of the overall usage of the Lam Ta Kong Watershed and will be 35 % in the future.
However, the water allocation policy in Lam Ta Kong Watershed is set the first priority for
Nakhonrachasima City will cause a conflict in water usage between the urban and the agricultural
sector in the watershed and these problems may encourage to social conflict later.