Preparing for the big melt

February 25, 2015 10:09 AM

There's tons (literally!) of snow on my little lot--right up against the house, up to and passing the sills of the first floor windows (not physically touching though). It will melt eventually. Obviously it's going to be a wet spring, but is there anything we can/should be doing in advance to mitigate the chance of basement flooding?

We have a sump pump, and during a big rain (3+ inches over the course of one day), the pump kicked in and did heroic work pumping out the sump pit and keeping our basement dry. Obviously, the snow is not going to melt all at once.

I don't know how old the pump is, and there currently isn't a battery backup redundant second pump. In addition, the pump is pumping into the basement sink, rather than pumping outside, so there's a limit that it can pump out at once. This is not code, and I will have that fixed in the spring, probably adding a dry well and definitely upgrading the pump.

So, the pump situation is not ideal, and this snow is going to melt. Is there anything we can do to minimize the chance of flooding given our pump situation?

Should we dig out the house as best we can? Use the snow blower to move snow to far corners of our lot / closer to the storm drain?

Does it make sense to upgrade the pump and re-route it now to a corrugated pipe outside and deal with digging after the ground thaws?

Bonus: who deals with sump pumps? Better to get a plumber or one of those basement waterproofer companies?

posted by Admiral Haddock to Home & Garden (9 answers total)

To be clear, the big rain that set off the sump pump was in December, and entirely unrelated to the snow. More of an anecdote to suggest that ground saturation has threatened my basement in the past.
posted by Admiral Haddock at 10:15 AM on February 25, 2015

The biggest problem with melting snow are slush/ice dams (not the roof kind). As the snow melts you HAVE to keep the drains and gutters clear. So, starting at the street, work backwards toward your house and make sure the path that water takes to run away from your house is clear of unmelted snow and ice. This will be an ongoing job as slush will continually clog up the path.
If your gutter in the street is clogged don't what for the city to clear it-get out a shovel and work on that. If enough snow has melted you can use your car to crush/move the snow by driving slowly along the gutter with the tire right against the vertical part of the curb.

Snow has a water capacity of basically 12 inches of snow equals 1 inch of rain. plan accordingly.
posted by bartonlong at 10:18 AM on February 25, 2015

If possible, create a channel for the melting snow's water to flow away from your house. This will of course depend on the topography of your land, whether or not this is even a possibility.
posted by oceanjesse at 10:48 AM on February 25, 2015

+1 about drains and gutters. Just like leaves, slush will block drains and cause backups--not to mention all the stuff that gets carried along in the melt.

Thinking long term (not just about this winter), it's worth looking at the grading of your property as well. You want the water to flow away from your house, not towards it, and if your property slopes so that the water will pool against the foundation that can be a problem.

Obviously, the snow is not going to melt all at once.

Don't be so sure. It is a lot of snow, but some years all it takes is 2-3 unexpectedly warm March days to cause an almost complete melt, and resultant flooding. It might happen slowly, or it might come pretty quickly, hard to predict.
posted by epanalepsis at 10:50 AM on February 25, 2015

In general, melting snow does supply water much more gradually than a good downpour (unless you have a jump from freezing to, say, 70° F, which seems a bit unlikely to happen).
The usual problem is gradual water built-up in not properly cleared areas. Determine the general direction of water flow at crucial house-endangering points, and make sure to bust through any snow walls that prevent proper draining.
Also: tale notes, make a plan for re-landscaping during the summer. Your next winter will be much more relaxed.
posted by Namlit at 11:31 AM on February 25, 2015

We had new-home-owner excitement when our sump pump failed a couple of years ago. Of course it did so during a big rain, when everybody wanted pumps, so we had to call 3 different stores before we found an appropriate replacement in stock. If you know the pump is old, consider having a backup on hand to swap in. Also, if you put at least one battery-powered water alarm in the basement, you'll know when you need to spring into action, before you just stumble into 2 inches of water when you go downstairs to do laundry.

Thanks to other posters for the snow advice; I may try some of that myself.
posted by aimedwander at 12:36 PM on February 25, 2015

I would definitely move the snow away from your house and I might even think about putting down tarps near your house along the roof dripline, if the gutters get iced up or overloaded (which is bad as it can also lead to roof leaks...) so that the water is forced to run further away from your house before it soaks into the ground. You don't want the water backing up to your house and running vertically down the exterior surface of the foundation.
posted by Kadin2048 at 1:12 PM on February 25, 2015

Maybe this is obvious, but make sure everything in your basement is off the floor too. Ideally you wouldn't have anything stored down there in case of flooding, but if you don't have alternate storage space then at least invest in wire shelving and plastic bins, rather than cardboard boxes stacked on the floor.
posted by vytae at 2:56 PM on February 25, 2015

The snow is not going to melt all at once unless there is a huge rainstorm. Even then, snow holds the water so it drains rather to wherever. I have a less than $100 electric pump designed to pick water off a flat floor when it's only a quarter inch deep. It exhausts thru a garden hose (to your sink or out a window). Something lime that could be a cheap backup.
posted by SemiSalt at 4:20 PM on February 25, 2015