PROBLEMS FROM DEVELOPMENT 99 



charge, will the progressive decline of water level in the well 

 be arrested. 



The areas where significant cones of depression have been 

 formed in the original water surface, whether water table or 

 artesian-pressure surface, are shown on Plate III. The distinc- 

 tion as to whether approximate equilibrium has or has not 

 been reached is strictly tentative, for a substantial increase in 

 draft in any area will result in further lowering of water levels. 

 In several areas, particularly coastal areas, the decline of water 

 levels has been accompanied by encroachment of unusable 

 water into parts of the aquifer. 



Pipeline problems most commonly afflict cities and indus- 

 trial areas that use large quantities of ground water, whether 

 in humid or arid climate. Several of the areas of concentrated 

 draft are within the overdeveloped reservoirs outlined on Plate 

 II, and water levels are declining in them more rapidly than 

 elsewhere in the reservoirs. 



A general lowering of water levels over a broad area has 

 been recorded in some aquifers where wells have been widely 

 dispersed, resulting from a coalescing of the cones of depres- 

 sion formed by the individual wells. The conditions are super- 

 ficially similar to those in overdeveloped aquifers where draft 

 exceeds replenishment. There is the difference, however, that 

 the developed areas are remote from the recharge area and 

 that examination of the recharge area shows no depletion of 

 storage there. The draft from wells, therefore, has exceeded 

 the quantity of water that can move from the recharge areas 

 to the wells, and the inadequacy is in the transmissivity of the 

 aquifer rather than in the recharge. 



The solution to the pipeline problems of apparent or local 

 shortages of water is to bring the rate of draft into balance 

 with the rate of replenishment, either by reducing the draft 

 or increasing the replenishment, or both. Thus the principle 

 is the same as that involved in the elimination of overdraft 

 from reservoirs where long-accumulated storage is being pro- 

 gressively depleted. Since many of the apparent shortages are 

 in humid regions which have water surpluses at least in cer- 



