Flexible fluid reservoirs with closures and structural members

A fluid reservoir, comprising:

• a 3-D formed first sheet and a 3-D formed second sheet, wherein the 3-D formed first sheet and the 3-D formed second sheet are sealed together at least partially around respective perimeter edges thereof to define an internal space for fluid storage, and wherein the 3-D formed first sheet and 3-D formed second sheet have different shapes that when sealed together define a curved vertical profile of the fluid reservoir;
• a first opening defined between the 3-D formed first sheet and the 3-D formed second sheet at a first end of the fluid reservoir, wherein the first opening is fitted with a first plate sealed to the 3-D formed first sheet and a second plate sealed to the 3-D formed second sheet to define a fill port configured for filling the fluid reservoir with fluid;
• a second opening defined between the 3-D formed first sheet and the 3-D formed second sheet at a second end of the fluid reservoir opposite the first end, the second opening having a fluid exit port seam-welded to the 3-D formed first sheet and the 3-D formed second sheet and configured for allowing fluid to exit the fluid reservoir;
• at least one collapsible baffle formed of a web of flexible material, the collapsible baffle being positioned within the internal space and having a first end welded to the 3-D formed first sheet and a second end welded to the 3-D formed second sheet, wherein the 3-D formed first sheet and 3-D formed second sheet have a continuous outer profile on respective outer surfaces thereof in areas adjacent the first and second ends of the baffle.