The disclosed water barrier systems may include a first mobile water barrier, and adjacent second mobile water barrier, and a translation mechanism for translating the first mobile water barrier and the second mobile water barrier toward each other. Lowering mechanisms may be configured to lower sidewalls of the mobile water barriers. The mobile water barriers may include sealing elements to form water seals between the adjacent mobile water barriers and between the sidewalls and a surface. Related methods of forming a water barrier assembly are also disclosed.