▁means ▁of ▁q an ats ▁they ▁transfer ▁this ▁water ▁to ▁a ▁distance ▁of ▁ 5 0 ▁or ▁ 6 0 ▁kilom eters ▁or ▁sometimes ▁further ▁down stream . ▁No ▁nation ▁in ▁the ▁world ▁can ▁comp ete ▁with ▁the ▁Iran ians ▁in ▁recover ing ▁and ▁transfer ring ▁ground water . ▁They ▁make ▁use ▁of ▁ground water ▁in ▁ir rig ating ▁their ▁far ml ands , ▁and ▁they ▁construct ▁q an ats ▁almost ▁everywhere ▁and ▁always ▁succeed ▁in ▁extract ing ▁ground water .” ▁ ▁The ▁dynast y ▁of ▁Q aj ar ▁ruled ▁Iran ▁from ▁the ▁ 1 6 th ▁century ▁to ▁the ▁early ▁ 1 8 th ▁century . ▁According ▁to ▁G ob lot , ▁the ▁time ▁of ▁Q aj ar ▁can ▁be ▁considered ▁as ▁the ▁he yd ay ▁of ▁q an ats , ▁for ▁the ▁q an ats ▁could ▁fl our ish . ▁Ag ha ▁Moh amm ad ▁Khan ▁the ▁founder ▁of ▁the ▁Q aj ar ▁dynast y ▁chose ▁Te h ran ▁as ▁his ▁capital ▁city , ▁a ▁city ▁where ▁there ▁was ▁no ▁access ▁to ▁a ▁reliable ▁stream ▁of ▁surface ▁water ▁and ▁it ▁had ▁to ▁rely ▁on ▁ground water . ▁The ▁rich ▁supply ▁of ▁ground water ▁and ▁suitable ▁ge ological - top ographical ▁conditions ▁of ▁Te h ran ▁allowed ▁this ▁city ▁to ▁house ▁many ▁q an ats ▁whose ▁total ▁dis charge ▁amount ed ▁to ▁ 2 0 0 0 ▁lit ers ▁per ▁second . ▁H aj ▁Mir za ▁Ag has i ▁( r uling ▁between ▁ 1 8 3 4 ▁and ▁ 1 8