Hello again. I have another question regarding the construction of a house. I have a stream about 1-2 feet wide going down the left third of my property (5-6 acres). Looks a little busy right now with spring run off but also looks like it could dry out during summer. I don’t want to depend on that so I would want to plan my house with the thought that this stream is around all year. Sort of a worst case scenario (I do like streams tho).
I know I don’t want to replicate Frank Lloyd Wright’s Falling Water house in PA, so how close can I build to the stream ( I have about 100-200 ft leeway) and still be safe (i.e water free in my basement)?
Any special precautions I should be looking for now while planning this house build (we’ll start in a bout a year) or special considerations for the foundation? At the very least I would be planning for tarring the outside of the foundation, installing crushed stone at the footings and covering a drain pipe with additional crushed stone and a filter membrane (or hay) before backfilling a foundation. Probably would have the pipes drain off to a drywell or some such.
Any input and insights people have is appreciated.
Thanks in advance as usual…
Michael
Replies
I think that you are talking about too different things.
The stream is surface water and it would cause a problem if it flooded. I would check with some locals to ask about that. An 8-12" rain fall in a day or two might change that trickle to large roar.
Waterproofing and drains won't help with flooding.
Those help with sub-surface water and that has little direct relationship to the creek.
You need to be looking at thinks like slope, soil, and rock conditions.
Do local zoning restrictions apply? In my town, the stream (even seasonal), would likely be classified as "wetands" and I'd have a 75' setback. Not from the stream itself, but from the edge of the wetlands, wherever that may be. Example, the edge of the wetlands may be 50 or 75 feet from the centerline of the stream itself.
As far as water in your basement, test holes would certainly help define the water table. Now is the time, when the stream is at it's heaviest, to defiine the worst-case scenario as far as water levels. Test/perc holes will also help in your selection of a location for your septic field, if you'll be on your own, that is.
You're smart to address water/foundation concerns while still in the planning stage. I just returned from a just-completed house in Colorado that's on the Eagle River. Lot prep alone for water came to well over six fugures, and a crawlspace was built instead of a full basement. Not to be used as a comparison, as it was an excessively large house...but you can't fool Mother Nature. You can only try to appease her.
Thanks for the reply. We are in the process of having a perc test done on the land. I'll let you know what I find. I just don't know if this will prevent me from building a full basement or just a slab.
My guess (truly uneducated, but I am sure with the snow in the NH mts this stream is at it's height) is that now is the time to be looking at this.
I'll find out what the setback requirement is for wetlands.
Again, you guys are great. Thanks for the tips.
Michael
Most areas have flood plain maps. Check with your insurance office, real estate office, or local building official. They all usually have the maps. In some areas you can't build in a flood plain. My understanding is that the thing to look at is the size of the area drained by that creek (AKA: size of the watershed). If you can, you'll pay forever in higher insurance rates. If you're building with your own cash you could bear the risk yourself and not insure for flood damage, but any lender will require it.
On a side note: Always take as much time as possible between buying land and building on it. Spend time there in all weather and in all seasons. Check out the sun angle at different times of year (creek too, of course). There is quite a bit to be learned about every site. IMO if you ignore site specific conditions you'll usually pay for it in the long run.
Good luck on your project!It doesn't matter how fast you get there, it just matters that you go in the right direction.
You may also need to check with multiple jurisdictions as far as the setback is concerned. I also have a small creek (100 year flood plane as luck would have it) running through my property and EPA mandates (I think) 15' buffer. But my city recently passed an ordiance that increases the buffer to 75' but with what appears to be fairly liberal variance. The builder was operating within the EPA rules when they planned the subdivision and actually lost a couple of lots when the city passed its setback ordinance. They were pretty steamed about that.
Check the latest geologic survey and maybe invest in soil sampling. Both can give you an idea of the maximum size of the stream in rare, 100+ year, situations. You also might want to look upstream for a considerable distance and see if anything, or anyone, might alter the terrain and change the natural cycles. Sometimes people can add culverts or redirect tributaries that seem benign but can cause problems for a long distance downstream.
Stating the obvious some tiny trickles of streams can become wide raging torrents after staying small for decades so be careful. That said I have a distant relative who lives in a house that straddles a tiny stream coming from an artesian well. It is a major feature of the house. It stays constant year round and comes out cold. A fine spot for keeping the fresh caught fish and a six pack.
"You also might want to look upstream for a considerable distance and see if anything,or anyone, might alter the terrain and change the natural cycles. Sometimes people can add culverts or redirect tributaries that seem benign but can cause problems for a long distance downstream."
I think this is a very important point. Sometimes I think that the only thing people do is increase drainage.
Any and every kind of development upstream will almost certainly increase the amount of water running through your stream.
Rich Beckman
Another day, another tool.
Flood damage to your future house is only one consideration. The local enforcement agencies will have some guidelines for you.
Here, another concern is the erosion you make possible by disturbing soils on your lot so there are restraints on various types of activity within 50', 75', and 250' of differing bodies of water. for perennial streams it is 50' setback, horizontal distance. steep slopes can modify that upwards.
From a design and planning perspective, consider whether you might someday want to build a pond in your watershed and be sure to stay far enough back to allow for that.
Excellence is its own reward!