A joint study on ground water by the United Nations Children's Fund (Unicef) and World Wide Fund (WWF) has sought a tap on water used in the agricultural sector. The study has also sugested that the revenue from the tax should be retained by the body that manages the water system and arranges its equitable distribution.The body could be the local community or a local institution. Th study says the cost of providing water needs to be recovered. But while industry has to pay for it, irrigation does not (except for the extraction costs). The result is that ground water has come to be regarded as a free resource although it comes from common pool that is further put to misuse by excess withdrawals by rich farmers.