When buying or building a home in a subdivision, whether it is an existing home, one built on spec, or one you are contracting to have built, research the home drainage conditions of approval for the subdivision or minor partition that you intend to buy into.
You may find out some interesting things to consider, depending on where your prospective lot is located in the area, and the topography at the building site. Get a copy of the conditions of approval for the development, that was originally mandated to be complied with by the developer prior to the developer selling the lots or land.
The list of conditions of approval should have been completed prior to preliminary plat approval, which is required in most areas for the developer to sell the lots to the public, and not just take reservations on them, not legally binding. Not really an option, but pretty much the same effect. Conditional legalities may vary on the subject, from state to state as well.
The conditions of approval are mandated by the county or city, to be completed prior to the first lot being offered for sale by the developer. Look into this information closely, especially when looking at waterfront, 100 yr. flood plane, and other low lying lake areas, as well as steep hillside communities with switch back road systems going up and down hills.
Look into everything closely within private gated communities as well. Some of this information make look extensive, and it is, but you can get free help translating it at the city planners and permitting office in your area, in most cases.
Look into the need for flood insurance as well, if you think it could impact your prospective lot and home.
The larger and more expensive the neighborhood, the more you should research the conditions of approval . Ask the next door neighbors about any home drainage problems they may have, and if they have any information with respect to the home drainage health of the neighboring home you are looking at. You would be surprised how many times I have hit a home run with that one.
Neighbors will tell you everything. They may not even like the current homeowners, and are happy to fill in the blanks for you. Just ask nicely.
What does the neighbor say about the drainage in the neighborhood in general that you are thinking of buying a home in? Do they have stories of underground rivers and springs in the area, where almost everyone has a sump pump installed and almost everyone still has groundwater problems and damage to their homes as a result.
Ask a few of them to tell you their stories of underground rivers and springs. Ask them if the source of the story was someone without hand excavated french drains installed. Probably.
Until a developer satisfies the conditions of approval for the subdivision and actually completes the work that corresponds to the conditions of approval, the developer can only sell reservations on the lots, subject to the final completion of the preliminary plat approval and the satisfaction of the conditions of approval.
The developer in Oregon is prohibited from advertising the lots or land for sale prior to satisfying the conditions of approval for the subdivision. This is true in most states in the U.S.
Make sure the developer actually installed the community home drainage systems that were mandated. Some developers get away with not doing anything much at all in boom markets by cutting corners or buying off the inspector. When no one is looking, weird stuff happens.
This is especially true in small rural residential areas where a particular developer is in great control of the county government, inspectors and the real estate sales marketing process in general. Some old bubba who hands out spiffs to everyone to keep the power base working well. Sounds like the mob, right?
“Look for a bear behind every tree”, I say, when it comes to home drainage. Especially on the larger macro level, like due diligence for verifying the installation of community drainage infrastructure.
In many cases a developer can save hundreds of thousands of dollars not doing work such as major groundwater removal and storm retention facilities. Developers may do the big stuff alright, like the storm water retention pond itself, but look for some slip sliders to cut out many of the more functional, precise, and expensive small groundwater collection systems along homes and streets, that were meant to feed that retention pond with groundwater during hard rains.
When you enter a subdivision with standing street water during hard rains it may be normal but if the groundwater is still there a day after it rained, you have a problem.
Inspect the conditions of approval list, a document of public record, to see what was mandated for drainage in the area you wish to buy into. You can do this with free help at the planners office in the county or city you are dealing with.
The short list is: Determine if the developer actually completed the road drainage culverts, storm water retention ponds, etc. and if so where are they? Find out if the stormwater retention ponds were even excavated and where they are. Find out where the road drainage ditches are and where they go.
Ask yourself if the drainage along the roads has large stable rock lining the trench that is the structure of the road drainage ditch. Are there large culverts under the roads where they intersect, where groundwater can run under the road instead of over it. Are there retaining walls along hillside bank cuts to prevent slumping of perhaps freshly cut hillside bank onto people or roads at some time in the future, when rain is coming hard and even huge trees are falling from the groundwater saturation.
Does the subdivision contain low point drains, street low point drains, bio-swales, road grate drains, curbs and gutters, sidewalks, and other items that may be on the list of conditions of approval for the subdivision. Included is usually the creation of playground areas and other common areas to the subdivision or minor partition. What is the drainage plan for the common areas and playgrounds. What safety features were mandated, if any, for creation and installation of the playground, and was the frame work followed properly.
Ask yourself where the groundwater from the low point drains, streets, roofs, lawns, culverts and ditches vent to? Where does it all wind up. In a stormwater retention pond or lake, or a storm sewer?
Ask these questions at your local bureau of buildings planning and permitting department. They can provide answers in most cases without as much work being put into this process as you think. Perhaps a 20 minute conversation.
Find out if any community drainage or domestic water source pipes, usually of large diameter, like storm sewers, have easement to, and indeed do pass through the lot you are looking at? How large are they, where are they located. How old are they? What is the systems maintenance schedule and who does it and pays for it. Who repairs your entire back yard after someone from the city digs it all up to get to some failed community storm sewer system or the like.
Will you be required to allow access to a clean out in your rear yard somewhere that belongs to some community groundwater system? What does the easement language say about it if it does, and where is it located?
While this may seem excessive, it is not. A home is probably your most expensive possession. This subject is very important.
I spent 25 years selling land to developers before starting this company many years ago. I have spent two professional careers involved with the land acquisition and permitting process, as well as home drainage science.
Home drainage is a real sleeping giant. It can reward you when it is well done, and damage your home when it is not done well.
Consult a licensed, bonded and insured home drainage contractor in your part of the world to help you figure out your home drainage problems. A professional home drainage contractor will offer you a free evaluation of your land or home and probably spend hours with you talking about what you need to learn about.