it ain't no trick to get rich quick if you dig dig dig with a shovel or a pick

March 17, 2012 7:42 AM

Backyard drainage/flooding issues: please help me choose an excavating contractor and get the job done right.

My backyard is a swamp! It's all settled over the decades and water doesn't run off into my neighbor's yard (and through there into the city sewer) the way it was originally designed to. Neighbor and I are at the low point in our immediate area. We get about 3 weeks in July when we can walk across the backyard to the garage without workboots. It's great for the loveliest willow tree ever (my backyard) and a half-dozen happy chickens (his backyard) but not so great for dogs and kids and people who want to use the yard without needing to be hosed down afterward.

So I'm getting estimates from excavators. This is not your typical home improvement job so I have no idea what I am looking for, what I am asking for, what it should cost, and how I will know it was done right. Everyone has a plumber to recommend, but there's little word-of-mouth for residential excavating work. I'm looking at the yellow pages and craigslist.


First guy comes, looks around, and says "yeah I can bring in a truckload of dirt and build your yard up." Not inspiring confidence. A week later he drops off a hand-drawn sketch on the back of an envelope with the word "estimat" on top, wants $2,500 to run french drains from one side of the yard through the neighbor's yard to the ditch.

Second guy came last night, said I need a "dry sump" ~15-ft. deep plus a few french drains from the edges of the yard that route into the pit, is putting together 2 estimates, 1 for me alone and 1 to share with the neighbor if he wants to extend the pit into his yard to help with his drainage issues as well. His off-the-cuff estimate was $3,500 depending on the cost of gravel on the day of the job. Labor=1 day to dig/fill, 1 day to fill low spots around the yard using the dirt from the dig.

This is a lot of money. And like I said, I have no idea how even to evaluate the estimates or the quality of the work. Second guy sounded like he knew what he was talking about, but then he also wanted to know who else I was seeking bids from and proceeded to tell me not to hire guy x and guy y because they'll give me lowball bids and then bury me with add-ons outside the contract ("oh we didn't expect tree roots" or "gas prices went up" or whatever). So I've got that added scare (what good is a contract if they can change it?) but also it's a red flag to me when someone puts down a competitor in order to build himself up. I get that contractors do it all the time but it makes me question their integrity.

So if you are in the business, or if you have had this kind of work done, what should I be looking for/asking for/paying? What should I be looking out for/wary of?

I'm in Roanoke VA, property is less than 1/4 acre and it's only the backyard, the area has some limestone but there's no expectation of them hitting bedrock or anything like that, 1 overhead power line to clear but otherwise nothing above or below to worry about (but we'll have Miss Utility out to mark lines). Guy2 said we wouldn't need a city permit due to the property size.

posted by headnsouth to home & garden (6 answers total)

Guy2 said we wouldn't need a city permit due to the property size.

I'd check with the city directly on that.

The best way to get a recommendation for someone in the trades is to ask someone else in the trades. So if you have a plumber that you trust, or a friend who is a general contractor, or whatever, you should be asking them for the name(s) of a good excavation guy. They all overlap on job sites, and they learn who has a clue and who doesn't.

If the problem is settling, you probably want to build things up, but of course the devil is in the details. Best would be to coordinate this with your neighbor so you don't get one of those uncomfortable situations where you've now routed the entire neighborhood's drainage into his backyard.
posted by Forktine at 8:02 AM on March 17, 2012

Yep, have asked my electrician, have asked around as much as possible, posted on local forums, talked to the commercial contractors who are renovating our building at work, etc. No word-of-mouth on this one. Neighbor and I are working together (which is why I asked guy2 for 2 estimates so neighbor can address his water issues too, and my #1 priority is to not cause problems for someone else. This is something I'm concerned about, however, & is part of the reason for my question. I don't know how to evaluate either the estimate or the work and don't want to wait until the next big storm to find out we've caused another problem (or not alleviated the existing one).
posted by headnsouth at 8:09 AM on March 17, 2012

Guy2 said we wouldn't need a city permit due to the property size.

I would be very surprised that you wouldn't need permits, since your are altering local drainage. Municipalities tend to care very much about those things.

I suggest you ask a large landscaping/landscape archicecture business about these things.
posted by Thorzdad at 8:12 AM on March 17, 2012 [2 favorites]

I am an engineer for a city at the other end of the nation from you, however most of the regulations about this kind of thing are in federal code and so should still apply. Drainage issues are pretty much the whole reasons civilization and my profession exists and public works departments are really, really concerned about this. You can NOT just push the water flowing onto your lot (as the low lot in an area you are kind stuck with it) onto someone else's lot.

The two options you have are to 'dispose' of this water is to get it into the cities storm water system (if such exists near you) or to get it to soak into the soil and the aquifer faster. One option is a swale or raingardern. OSU publishes a really good guide for it (and an extension service near you probably does to but this is the one I know about). Most of the time this doesn't require a permit and you might even be able to do this yourself.

If you don't have the right kind of soil (and you may not from your description) you can get a drywell installed (I think this what the second contractor is talking about). A drywell is a hole that is dug down directly into the aquifer if shallow (say less than 15' down) or into a soil layer that can accept a lot of water. In a lot of cases the low spot in an area was historically wetland and as such usually has a thick layer of organic debris that function as clay and once wet water can get through a clay layer (skips a long drawn out explanation). This is probably what is going on in your case and underneath this top impermeable layer the water will just drain away. So a drywell will probably work but since the ground water can get contaminated easily this way you usually have to register them with the local Department of Environmental Quality (or whatever VA has).

You should start this process with a conversation with your local public works department to determine the best approach for you. Depending on this you might need to hire an engineer first than a contractor once you get some idea what your site conditions are. If you can just put in a drain and hook into the city stormwater system you can hire a contractor and just put in some pipe-but guaranteed you will need a permit.
posted by bartonlong at 8:53 AM on March 17, 2012 [2 favorites]

Seconding what bartonlong said and adding this: Everybody downstream from you may be able to look to you for damages from flooding if you do not go to the city for permits (and even if you do). All of the stuff about environmental quality can come back to bite you as well. A dry well is an ideal way to solve the problem BUT only if it is done right and does not end up having to be mitigated because the city decides it should have been done differently or not at all. That experience can get very expensive. Start at the city. Explain the problem. Ask their advice and see if you want to go the the expense of doing it right. If not, buy a lot of boots. Those are your only options.
posted by Old Geezer at 7:45 PM on March 17, 2012

Thank you bartonlong. I appreciate your response. I called the city today. All three of the affected neighbors are on board with doing this right, sharing costs, etc. Being in the middle and not having access to the sewer (and my front yard is a smidge higher than the back), I think I will bear the most cost, but we all want to be able to use our yards.

Guy2 did give me a formal quote, but I told him I am starting with the city and we'll see what happens. He seemed really eager to get me locked in before I got additional bids, telling me his big jobs usually started in April so we only have a week or so before it'll be hard to fit my small job in. I'm sure he's legit but it's too aggressive for my comfort.

I like the swale idea but would still have to have a pro do it, as currently the lowest point is right where we want to be walking and it would all have to be regraded.

We'll see how it goes. Thanks again.
posted by headnsouth at 3:00 PM on March 19, 2012