Just this one at Calexico, CA is currently going. Twenty miles just West of El Paso, including the Santa Teresa Border Crossing, has had the contract awarded, so they should start construction in the next few weeks. Both of these project are estimated to complete in about a year from start.
Now that the new money has been released, contracting actions should be under way (not public, just among pre-approved vendors from last year's preparations) for more segments. Contracting could take anywhere from a few weeks to six months.
Fourteen miles of double barrier (14 x 2) was authorized in San Diego, but Trump may hold that up to pressure California politicians. Five miles goes to El Paso itself, and there is about twenty miles that I am unsure of (Santa Teresa?). The big effort in this group will be the Rio Grande Valley.
28 miles of levee wall with bollards in Hidalgo County, plus eight more in neighboring Starr County, will fill in the existing gaps to completely wall/fence off the McAllen Texas metro area (except for the Santa Ana Wildlife Reserve outside of town, which will take any flooding that occurs). It will be a big fortification of the Rio Grande Valley, where the most crossings occur.
When these projects get underway later this year there will likely be a half dozen or more crews working at once. There are still lots of variables, especially if Trump shifts the San Diego effort elsewhere.
