Over 90 % of the area in the watershed is either used for agriculture or covered with forest. Agricultural land is generally concentrated in the southern sub-basins and the majority of forest cover occurs in the north.
In recent years there has been steady encroachment of people into forest areas which has led to conversion to agricultural land, whereas land close to urbanised areas has been converted for residential or industrial purposes. The need to protect the upper catchment of the Chao Phraya basin from degradation and soil erosion has been identified as a priority by government.