we have rain coming in under our garage door. what can be done

Assuming that you have gutters going to a down pipe on the garage. I would suggest installing a slot drain similar to Aco Hex drain or Aco Doorway Drain. This would be placed in front of the door. the outlet would connect to the down pipe below ground level Via a sump unit to collect any debris. Regards Garry Howe

Fit an alco drainage channel along the front of opening, and run it into storm water drain or soakaway, via 100mm under ground drainage.

knock the garage down and rebuild it higher than the outside ground !!!! or you could consider installing an aco drain system between the garage and driveway, which should have been installed as standard practice if driveway slopes towards the garage. water has to drain off somewhere and that is usually the nearest rain water gulley/downpipe.