California has seen heavy rains, leading to flooding. Many cities have offered 10 to 20 sand bags per home.
Does this work?
Source: Sandbags to Protect Your Home From Flooding
It takes up to 100 bags to cover all potential water entry areas. If just one area leaks, water will gradually find its way into the home. For many people, 10 to 20 bags is likely to be insufficient to block all ingress points.
Bags with sand typically weigh about 35 pounds each and take 2 to 3 people to fill and deploy. It is said that it can take two people about an hour to fill and deploy a dozen bags. Perhaps a full day to surround all points of a home that needs all sides to be covered.
Bags and sand can not generally be reused. Flood waters are assumed to contain numerous pollutants, including raw sewage. Once this enters the sand, the sand will need to be disposed after the flooding.
The UK Environment Agency thinks other approaches should be used, including a special “FloodSax” brand alternative which is lightweight and easy to deploy. The FloodSax absorbs water and forms a 44 lb gel, per bag.
As that link notes, the Queensland Disaster Management authorities in Australia, and Lewis County, Washington State says sandbags are unreliable.
This is an interesting subject – it seems sandbags can be helpful in delaying intrusion of water, if properly used, but will generally leak, are difficult to deploy in sizeable numbers, and have issues with disposal after the flood is gone. What is your experience?
