DONNA, Texas (NEXSTAR) – Border Patrol officials are building yet another tent facility to house incoming migrants near the Donna-Rio Bravo International Bridge — adding to the current two tents that have opened in the past two months and doubling it in size — to meet the demands of immigrants arriving in the Rio Grande Valley.

Officials testifying before a joint House committee in Austin on Friday on immigration and border security announced the construction, telling lawmakers of the expansion of the tent city for migrants at the Donna encampment, as well as an additional tent facility being built in Tornillo, in West Texas.

Border Patrol officials told Nexstar that the facility will add 1,000 beds and should be complete by month’s end. That’s about as quick as the previous two tent facilities went up at the same Donna site. The first tent at the 40,000 square-foot tent encampment took just 13 days to build and opened in early May with 500 beds. A second similar facility was then built and opened in June, also with 500 beds. Both tents are air conditioned, have showers and are equipped with medical facilities.

“Due to the unprecedented number of illegal aliens in custody in the Rio Grande Valley Sector, U.S. Customs and Border Protection have allocated resources to further expand the Donna holding facility by constructing an additional soft-sided structure. The construction of the additional facility is scheduled to be completed by the end of the month and will increase the holding capacity by 1,000,” according to a U.S. Border Patrol statement.

On Monday, heavy equipment could be seen from the nearby highway moving dirt mounds, near the shell of the future tent. Giant white plastic strips hung from scaffolding and wooden beams and blew in the stiff wind as construction trucks came in and out of the compound.

Border Protection officials have said these facilities are not designed for long-term use and are intended to house arriving migrants — including families, unaccompanied children and single adults — as they are being processed by Customs and Border Protection, usually for up to 72 hours.

The growing encampment in Donna is now being referred to by some locals as the “migrant compound.” It is situated 20 miles southeast of McAllen, right next to the international bridge, and should help alleviate the overwhelming flow of migrants that Customs Border Protection agents are struggling to process at the McAllen detention facility.

Prior to the recent expansion, The New York Times reported that the Donna and Tornillo facilities cost about $40 million. Border Patrol officials would not comment on how much the new expansions at both sites are expected to add to the costs.