An apparatus for preventing a fluid from entering a basin, the apparatus comprising: a containment tube (310; 400) configured to fit within the basin and receive a filling fluid, further comprising: a top portion (140, 140A) that is suitable to fit within and span substantially all of a cross-section of an opening of the basin, the top portion (140, 140A) assembled piecewise from a plurality of pieces of material and having waterproof seams that connect the plurality of pieces of material; a base portion that is suitable to fit within and span substantially all of a cross-section of a bottom of the basin; and a side portion that connects the top portion (140, 140A) and the base portion, wherein a part of the side-portion is suitable to be in contact with part of one or more walls of the basin, wherein the top portion (140, 140A) is sealed to a first side of the side portion and the base portion is sealed to a second side of the side portion, and wherein force applied to the top portion (140, 140A) is re-distributed evenly when the containment tube (310; 400) is within the basin and filled by the filling fluid; wherein the containment tube (310; 400) is water-tight. a containment tube (310; 400) configured to fit within the basin and receive a filling fluid, further comprising: a top portion (140, 140A) that is suitable to fit within and span substantially all of a cross-section of an opening of the basin, the top portion (140, 140A) assembled piecewise from a plurality of pieces of material and having waterproof seams that connect the plurality of pieces of material; a base portion that is suitable to fit within and span substantially all of a cross-section of a bottom of the basin; and a side portion that connects the top portion (140, 140A) and the base portion, wherein a part of the side-portion is suitable to be in contact with part of one or more walls of the basin, wherein the top portion (140, 140A) is sealed to a first side of the side portion and the base portion is sealed to a second side of the side portion, and wherein force applied to the top portion (140, 140A) is re-distributed evenly when the containment tube (310; 400) is within the basin and filled by the filling fluid; a top portion (140, 140A) that is suitable to fit within and span substantially all of a cross-section of an opening of the basin, the top portion (140, 140A) assembled piecewise from a plurality of pieces of material and having waterproof seams that connect the plurality of pieces of material; a base portion that is suitable to fit within and span substantially all of a cross-section of a bottom of the basin; and a side portion that connects the top portion (140, 140A) and the base portion, wherein a part of the side-portion is suitable to be in contact with part of one or more walls of the basin, wherein the top portion (140, 140A) is sealed to a first side of the side portion and the base portion is sealed to a second side of the side portion, and wherein force applied to the top portion (140, 140A) is re-distributed evenly when the containment tube (310; 400) is within the basin and filled by the filling fluid; wherein the containment tube (310; 400) is water-tight.