If you are a prospective home site purchaser, that is to say, your objective is to buy a piece of land to build a home on, you need to understand the importance of doing your home drainage homework, prior to choosing and closing on your home site.
This means addressing an issue seldom discussed, home drainage and groundwater removal, as well as groundwater damage prevention methods. Land buyers must have the training to look at a large parcel of land and determine likely groundwater flow patterns that could impact the location for the homes foundation.
If the home is within an area not served by sewer, a contingency within your earnest money agreement must make your earnest money refundable, subject to a satisfactory perk test to establish the ability to get a standard septic permit for a septic system, so you can get the proposed new home financed and built.
There are other topics to discover as well, such as neighborhood and site home drainage considerations. Learning the infrastructure of where all that groundwater goes.
#1. At the head of the list is, looking at the soil grade of the site, with drainage in mind. Other important considerations to study within the due diligence phase of your real estate transaction to buy the land are:
#2. The geology of the underlying area, which is available in the county planning office, or by using US geological survey information, that is public record.
#3. Look for any geotechnical reports that were submitted by the developer, if there is one involved, as part of the satisfaction of county conditions of approval for the subdivision, when the subdivision was originally platted and approved.
#4. Find out if there are any pre-approval requirements of property and homeowner for financing made available for building a home in that area, and the terms that apply to the financing, such as the loan to value requirements, term length, fire safety issues, and other pertinent conditions of approval, made part of the loan program, by the lender.
#5. Write earnest money agreements with clauses to protect your earnest money, should you find disturbing information during your due diligence phase, prior to removing all contingencys and proceeding with the purchase of the land.
#6. Discover and inspect any community groundwater systems that service the community, if the land is within a platted subdivision or minor partition.
Review any easements that may affect your prospective home site. Is the site a servient tenant or a dominant tenant. You must know if you are providing an easement of some sort, or if you are the beneficiary of an easement, in which case you are the dominant tenant.
#7. Scope out the topography of neighboring lots that sit above grade to your home site, and reflect on how they might impact your home, from a groundwater run off perspective, during hard rain periods.
#8. Look for installed road culverts, community drainage systems, and road ditches that were installed to handle groundwater running off ingress-egress roads connecting the subdivision.
#9. Check out the geology reports on any hillsides above grade to your property not built on yet. Slumping is common after trees and shrubs, once holding soil together, are cut down, and big rains pound bare hillsides.
Ask yourself: why has this lot not been built on yet. Ask yourself if the adjacent hillside lots have enough brush and trees, with roots strong enough to bind the soil to the slope during hard rains, preventing this dirt from winding up in your driveway or over your retaining walls.
10. Look for evidence of underground springs, especially if you see them running on the surface of the land you wish to buy in the summer months prior to the rains coming.
They do not have to be large during the summer months to become a real problem during the winter, as they really kick in due to the increased saturation of groundwater and hydrostatic pressure.
Ask the land sellers about the existence of any hand excavated french drains around the site or within the area, and if the seller has ever noticed any groundwater problems at all on the property, or in the general area. And last, but not least, ask the neighbors, as they will be your most truthful source of direct experience on the subject of home drainage in that area. Neighbors will tell you everything about the home and the current sellers, their neighbors. You will get the picture by just having a friendly chat with them.
No doubt this list will take some time to research, but the knowledge you will gain will serve you well.
Go to your zoning and planning department at the county level, after tying up the property on an earnest money agreement, by putting a contingency in the earnest money agreement to provide a reasonable amount of time for research of facts concerning the geology of your site, and the other aspects described above, prior to closing on your land or lot.
County planners can help you in this regard. Review any geotechnical information they may have available on the area. Look for records of any failed septic permit applications for the site. Ask the planning department for assistance in reviewing geo-technical data that is available on the type of soil and rock present within the area, the average well depth, and any past earthquake activity recorded. Ask about any recorded history of ground movement in the area.
Ask yourself questions like, “will the rain water run to my proposed home site, or away from it”? How will my road cuts affect the drainage. Where do I need culverts so drainage can run under roads instead of washing them out during floods.
Determine if this site will require collection for rainwater, do to the fact it is below grade to surrounding areas, other lots, or streets. If the area lacks curb and gutter and your site is below grade to the street, watch out. The lot at the lower end of a cul de sac, with all street areas funneling groundwater to the lower end lot is the one to stay away from, unless it has curb and gutter, and perhaps even then.
You may require hand excavated french drains just to keep your site from washing away. Everything changes once you pave “paradise and put up a parking lot.” Joni Mitchell.
Drainage issues must be in the budget from the beginning to make it all work. If you have not thought of it before, you will not budget it there after. Hire a licensed, bonded and insured professional home drainage contractor in your part of the world, to help you with these issues.
Most professional home drainage contractors will design your groundwater drainage systems for free.
Simply ask them for a free home drainage assessment, and if they are what you are looking for in the way of a contractor, respect the fact that their work is very difficult, hire them, and benefit from what they know that others do not know about hand excavated french drains.
Hire a seasoned home drainage/masonry professional contractor. Make sure your home drainage contractor is familiar with the concepts of groundwater removal that you will see explained in future articles within this home drainage informational web site.
Better yet, from your perspective as a land buyer and future home builder, is to contract directly with a home drainage professional contractor in your area, to install rain drain discharges at an engineered grade instead of installed flat on the outside of the foundation footing, like most still install them when the home is built.
Install hand excavated french drains around the home when the home is built, and get a longer lasting and a much better system.
Exclude the amount of the drainage contractors bid from the price of the home builders contract, and if you get a great deal of guff from the home builder about it, it is probably a good idea to find another builder.
Many contractors say they understand the complex issues of home drainage. In my experience most do not. They huff and puff and threaten to blow the house down when confronted with the issue, but it is your decision.
I have addressed the fact that home builders are not competent to be trusted with the installation of hand excavated french drains, and they almost always lay rain drain discharges and foundation footing drains flat on the outside of the homes foundation footing, without a grade to clean the solid pipe of debris. The flat installed systems plug within months to years.
Many contractors simply have a professional drainage contractor/mason come into the picture from the beginning and contract directly with the homeowner, as they know they do not understand home drainage from their own experience. Landscapers many times say they are home drainage professionals as well, but they almost never are. Most are really just bluffing it with a pick-up truck and a trailer with a few lawn mowers and rakes.
My experience has been that most landscapers do not understand the degree to which hand excavated french drains need to be engineered and installed.
This is the pacific northwest of the United States, Oregon specifically, and this is where home drainage problems separate the men from the boys, when it comes to the installation, design, and perforamance of hand excavated french drains.
Many websites addressing home drainage installation are posted by landscapers, home repair advice writers, tv shows, and other non full time professional home drainage contractors and are not even close to reality. I do not agree with most of what they say, or their definitions of french drains, and/or their proposed groundwater solutions, for that matter.
It is for this reason, as well as others, that this forum on home drainage is being offered for your review and consideration. Study of this website will put you in a knowledge based position to hire a professional home drainage contractor and know who you are talking to and their likely abilities, as well. Don’t be fooled again.
Many homeowners will use the information to help them install their own hand excavated french drains. Many other readers will use our telephone consultation service or on site supervision service to help them design and manage the installation of the appropriate home drainage system in their area of the world.
Most of our readers will be Oregonians with home drainage problems, that will have come to this site as a choice, and not by any mistake. These readers know what they are facing, and have been lead to this informational source for a very important reasons. Study. Arm yourself with knowledge.