Many different systems were evaluated. A barrier dam solution needs vertical elements (visual disturbance) or they could be hydraulically lifted, but it is difficult to create a water-tight seal. Also, the pressure of holding back water above three feet becomes difficult. Even if barriers are erected around the house, once the water rises above 4-5 feet, the pressure would push the water below the barrier system and the water would rise on inside the barrier. Cofferdam systems would work below grade but would need a an above grade curb along with a very complex system of hydraulically raised walls tied to the below-grade cofferdam that would rise up to form the above-grade dam that would somehow have to be sealed to the curb and to the adjoining elements. Rubberized plastic barriers that are inflated with water are not designed for these heights of water and they are not anchored. These systems are not designed for quick response. Limited staff capacity dictates that any new system can be activated by one person in less than two hours during poor conditions. The costs of these systems have not been estimated and the site aesthetics would be compromised.