Dear Arun,

Eucalyptus is also known to cause a number of environmental hazards like depletion of groundwater, dominance over other species by allelopathic effects, loss of soil fertility and negative impacts on local food security issues. A study initiated to document and quantify the adverse impacts of growing Eucalyptus in Kolar district of Karnataka state in India indicated that 20 years of continuous cultivation of Eucalyptus in private and public lands deepened the water level in freshly dug bore wells to 260 m, as compared to the mean depth of water level in bore wells (177 m) in the study area of 21 villages of Kolar district. The distance from the eucalyptus plantation had negative correlation with the depth of freshly dug bore wells. The bore well yields were reduced by 35 to 42 per cent in the study area during the span of 3-5 years, when they were located within a distance of 1 Km from Eucalyptus plantations. The reduction was to the tune of 25 to 37 percent, when bore wells were located within a distance of 1-3 Km from such plantations. These observations were recorded under identical set of soil, rainfall, rock formations and cropping patterns. Reduced irrigated area, reduced profitability, increased cost of lifting the water and resorting to digging more bore wells (with a blind hope that farmers may strike more water in new bore wells) are recorded as prominent negative impacts of growing Eucalyptus continuously for the last 20 years

With my best regards

Prof. Bachir ACHOUR 

Yes. Mr. Arun Kumar.

Because of this nature, this excotic species are mainly recommended in saline/dry areas to curb the water from nearby areas. 

According to my knowledge, any tree species consumes water depending on its vegetative mass and effective or active depth penetration of the root system. Though there is a general belief that Eucalyptus trees consume more water, there are reports contradicting the same, stating that there are more than 20 species of Eucalyptus & not all of them consume same amount of water. The only argument against growing Eucalyptus is that it should not be done in water scarce region, as these trees can be grown in any dry areas or saline pockets or water logged areas. Other reasons against growing Eucalyptus trees are the ecological & soil fertility problems. As far as Kolar region is concerned, the area is water scarce and experiences recurring drought and hence definitely not advisable to grow any water intensive crops/trees.