The returnees assembled on the banks of the Ahava waterway that flowed through the district of Babylon that bore the same name. The site is presently unknown. [source][source][source]
". . . Babylonia was crisscrossed by a network of irrigation canals that tapped the water of the Euphrates and flowed toward the Tigris, which had a slightly deeper bed." [1][source]
No Levites had volunteered to return to Judah. In view of his plans for the restoration, Ezra needed more Levites than those already in Judah. Due to his recruiting efforts in Casiphia (site unknown, probably a district of Babylon), 38 Levites and220 temple servants joined the immigrants. One writer estimated the total number of men who returned with Ezra as about1 ,700-plus women and children. [2] Another calculated the total number of men, women, and children as between4 ,000,5 ,000. [1][source]
Chronology of Ezra 7-10YearMonthEvent4581Ezra led1 ,700 men out of Babylon ( Ezra 7:1; Ezra 7:8).Ezra"s party left the Ahava waterway.2345Ezra"s party arrived in Jerusalem.Shecaniah proposed a solution to the mixed marriages problem.6789The Jews agreed to dissolve their mixed marriages.101112The Jews finally dissolved113mixed marriages. [source][source][source]