Remaining Water Resources Potential

Surface Water Potential

In terms of the quantum of the surface water resources, the flows of Indus and its tributaries, available to Pakistan, are the most significant. The meager and highly variable flows of all other streams, offer only, a limited potential for adding to the stock of water.

Season wise the situation is that during Rabi all the natural river flows are captured, and the diversions are augmented from the storage releases. The out flow to the sea during this season is negligible. During Khairf, however, the river flows exceed the diversion by highly variably amount and end up in the sea.

The water out-flowing to the sea, amounting to 50.60 BCM (41.02 MAF) thus represent a potential source for the future development of the water resources. 

Apart from the water going to the sea, there are large water losses in the irrigation systems. These losses are due to conveyance losses in the distribution system which are lost to evaporation and due to seepage from the conveyance channels and from the fields which constitute groundwater recharge. The seepage that takes place in areas where the groundwater is brakish is not retrievable for reuse and its saving can add to the water resources. 

Groundwater Potential

Recent estimates of the availability and use of groundwater of an acceptable quality indicate that this resource has been heavily exploited. There are indications that in some areas, the annual groundwater pumpage exceeds the safe annual yields and the water table is declining. It is only in small area and under restrictive conditions, that additional use-able groundwater can be exploited. 

In an overall context, the safe groundwater yield is estimated to be 67.85 BCM (55 MAF), whereas the extraction is of the order of 59.21 BCM (48 MAF). Thus the remaining groundwater potential is about 8.63 BCM (7 MAF) representing a possible increase of about 14 per cent only.