How about something like these plastic jersey walls? You can move them around easily when empty then fill them with water (and calcium chloride to prevent freezing).
You can get them in any color you want. We use them at work.
http://www.plasticjersey.com/plastic-jersey-model-comparison/
You can get them in any color you want. We use them at work.
http://www.plasticjersey.com/plastic-jersey-model-comparison/