Home Depot offers the Quick Dam 17-Foot Water Activated Flood Barrier for $22.28. (Amazon charges the same.) Choose in-store pickup to dodge the $5.99 shipping fee. That's the lowest price we could find by $6. It's reusable and works to absorb and divert water.

Update: The price has increased at Home Depot; however, Amazon still offers it for $22.28 with free shipping for Prime members.