The clogging of pipe drainage system by iron compounds is a complicated and not yet fully recognized process. There are two ways of iron sludge formation in pipe drains: chemical and biological. Chemical formation of iron sludge follows in result of oxidation of Fe/HCO₃/₂ and its turn into insoluble iron precipitation called ochre. Now, the biological way consists in fixing iron by bacteria. Stickiness of the ochre formation is very high, but it can be conquered by 100-200%o pipe drain slopes. To find out the means for protecting pipe drains against iron clogging the content of iron dissolved in ground water should be determined. Iron clogging of pipe drains can be prevented using prophylactic means as well as by mechanical or chemical removal of ochre deposition.