Coastal zone groundwater management: Need for legislation

While planning for the coastal zone management, the groundwater component of the vulnerable zone is invariably ignored or neglected, as it is invisible to surface and needs indirect as well as modern scientific technologies to understand. It is needless to say that the Orissa coast is thickly populated and people depend on the groundwater for their domestic use, as surface water is insufficient in summer months, very often polluted, submerged by saline water. Frequent floods and cyclones also contaminate the surface water. The groundwater of the area is contaminated both vertically and laterally by ingress of seawater in various degrees.

Many government and non-government organisations work independently in this area without any co-ordination with each other. Everybody withdraws water from the sub-surface on his or her own will, assuming that the resource is unlimited and without realising the consequences of such abuse to the precious resource. Over the years, the population, industrialisation, demand for non-monsoon irrigation and wastage has increased many fold. This has led to the installation of a good number of high discharge pumping wells, which has put more pressure on the limited fresh groundwater resource. Lack of awareness and management, poor hydrogeological understanding, lack of proper legislation or disregard for legislation and poor enactment has multiplied the problem.

Fresh groundwater is restricted to certain geomorphic features such as beach ridges, natural levees and some palaeo-channels in shallow zone of the coastal area, under unconfined condition, which need to be understood and protected.

The deep freshwater is under hydrodynamic condition and under delicate balance of saline-fresh interface. The ignorance, improper well construction, unregulated withdrawal may disturb the balance and ultimately the whole aquifer may turn saline. The Herzberg principle says there is 40 times rise of saline groundwater for every metre of draw down of fresh water.

Therefore, the available freshwater is precious, needs good groundwater management practice with different protective and corrective measures. Rearrangement of the pumping pattern, safe withdrawal of fresh-water, scientific well design and adequate measures for artificial recharge should be practised in the zone to protect the aquifers from saline ingression. Awareness among the people can also help in better management of this valuable resource.

Legislations should be made and implemented firmly to control indiscriminate drilling, unscientific well design practice and abstraction of groundwater.