Surface runoffs that are used for artificial recharge usually contain a lot of suspended particles. These particles enter the artificial recharge installations by water and after sedimentation , cause a low permeable layer or move into deeper parts of soil and cause reduction in infiltration . This clogging phenomenon is one of the limitations for development of artificial recharge projects . In this research, the effect of clogging in Ramsheh and Kohroyeh artificial recharge projects in Isfahan Province and the effect of concentration and grading of suspended materials was studied. The results showed that average infiltration rate in recharge ponds of Ramsheh project decreased from 2 m/day to 0.5 rn/day and that of Kohroyeh project decreased from 1.5 rn/day to about 1.0 m/day in five months of the first operating period. The concentration of suspended materials in the water is the main factor which causes clogging and their grading had little Influence on the trend of this phenomenon. Removal of settled sediment layer (in laboratory study) was not very effective in restoring original infiltration rate. Primary settling of water to eliminate entering sediments can reduce the damaging effects of clogging
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