The Water Resources of the State are defined as all waters, surface or sub surface, existing within the state or passing through the state in any and all drainages and aquifers within the state. The geographical area of Maharashtra state is 308 lakh ha and its cultivable area is 225 lakh ha. Out of this, 40% of the area is drought prone. About 7% of the area is flood prone. The highly variable rainfall in Maharashtra ranges from 400 to 6000mm and occurs in a four month period between June - Sept with the number of rainy days varying between 40 and 100. The estimated average-annual availability of water resources consist of 164 km3 of surface water and 20.5 km3 of subsurface water.

In Maharashtra, of the 5 river basin systems, only 55% of the dependable yield is available in the four river basins (Krishna, Godavari, Tapi and Narmada) east of the Western Ghats. These four river basins comprise 92% of the cultivable land and more than 60% of the population in rural areas. An approximate 49% of the area of these four river basins consisting 43% of the population is already considered as deficit or highly deficit in regard to water availability. The size of these deficit areas is likely to increase steadily with increasing population and economic growth in the years to come.

Maharashtra’s share of the inter-state rivers has been decided by various tribunals appointed by the Government of India.

* 45% of state's water resources are from West Flowing Rivers which are mainly monsoon specific rivers emanating from the Ghats and draining into the Arabian Sea. This water cannot be fully utilized as the average altitude west of the Ghats (Konkan) is 60 metres above sea level; the average height of the Ghats is more than 600 metres above sea level. Affordable engineering solutions for lifting and transporting water from west to east are not yet available.