The number of families relocated from Tokwe-Mukosi to Chingwizi in Mwenezi has more than doubled to about 1 500.
Efforts are now underway to allocate them temporary plots to ease overcrowding.
Last week only 600 families were at the holding camp.
The increase in population at Chingwizi comes as the Tokwe-Mukosi relocation co-ordinating committee has dispatched soldiers and police into the basin to urge those remaining to accept evacuation.
An average 120 families are being relocated everyday.
Chairperson of the Tokwe-Mukosi relocation co-ordinating committee and Masvingo provincial administrator Mr Felix Chikovo yesterday said some families in the basin were reluctant to be relocated.
"We have so far relocated 1 471 families to Chingwizi and we dispatched security forces further into the dam basin to convince them to leave because there are some who are now waiting to harvest their crops first.
"We are saying all those who were assessed should be relocated because water levels in the dam might increase again in the event of more rains," he said.
Mr Chikovo said some families were now reluctant to move as rains have briefly stopped.
He said primary school pupils at Chingwizi were expected to start lessons this week as construction of a temporary satellite school was almost complete.
There are 790 primary school pupils at Chingwizi.
The health delivery service at the holding camp was also expected to improve as 10 volunteer doctors and six nurses are on the ground providing assistance.