What is the maximum retention level? It all depends on the model you choose. We provide barriers from 6-79 inches. The dam is effective from the first inch of water. admin2020-01-19T09:03:46+04:00January 19th, 2020|Flooding|0 Comments Share This Story, Choose Your Platform! FacebookTwitterLinkedInRedditWhatsAppTumblrPinterestVkEmail Leave A Comment Cancel replyComment Save my name, email, and website in this browser for the next time I comment.