DRAINAGE FOR YAZOO CLAY

This blog is about residential structures built with slab foundations in central Mississippi but it could also be used for residences with crawl spaces in this area. In this area lies one of the most active expansive clays in the world. It is called Yazoo clay. When this clay surface is above a depth of 10-11 feet of the surface, you should have adequate fall away from the house (positive drainage) on all sides. We often refer to this elevated surface around a residence as a berm. Typically you would need a fall of 8 or 9 inches in a 6 to 10-foot perimeter from the house with a Yazoo clay depth of 8 feet. In addition, the surface water that runs off of this berm must also be properly drained away without ponding. This is so important that it should be part of a local building code. This well-known construction fact is still violated by some home builders. Often the violation occurs on terraced lots where the lot is too small for the house. When this happens it is impossible to construct proper drainage away from the house without expensive retaining walls. These houses are often abandoned by their owners 10 to 15 years down the road when the owners are confronted with the cost of releveling plus a retaining wall and drainage that should have been part of the original construction. 

With less active clays like we find near Dallas and Austin Texas, these same rules would apply except that these less active clays must be closer to the surface than the Yazoo to create this need for good surface drainage. Surface drainage problems often go unnoticed in planting areas next to the residence that are covered with mulch. Typically depressions from erosion occur around the edge of residences that do not have gutters. Sometimes the depressions are inadvertently created when the planting is installed. To discover these areas the mulch must be removed and replaced.

There are 3 ways to improve drainage other than constructing retaining walls. There are two ways to improve surface drainage plus subsurface drainage. Retaining walls can be added to surface drainage to lower the grade and improve slope away from the residence. Surface drainage should be improved when water stands in puddles and maybe when the ground is mushy after rains in the same areas. Surface drainage might be improved by constructing drainage swales through a poorly graded yard. Otherwise, catch basins are installed with drain pipes. There is a significant improvement in quality when smooth pipe and concrete boxes are used. Higher quality systems are required when the ground is flat or there is potential for leaf or pine straw to clog the pipe.

Generally, subsurface drainage in central Mississippi should be designed by a qualified engineer. Subsurface drainage is only installed to remove groundwater. In central Mississippi, this is almost always a perched water table that is created above an impermeable layer like Yazoo clay that should be at least 6 feet deep. If your drain is not as deep as the impermeable layer the groundwater can just pass underneath the drain. Poor subsurface drainage is hard to detect without soil borings. Be very cautious if someone recommends subsurface drainage without the aid of soil borings. If water is not initially detected in the boring then they should be left open for at least 24 hours. You might detect groundwater with hand-dug holes if it has not rained in a week or so. But typically hand-dug holes will not be deep enough. Note that water standing in a hand-dug hole a day or two after a hard rain might just be surface water that has saturated the upper layer of soil and may not be a condition that justifies a subsurface drain. Also if you suspect a leaking water line, you can test the water in a boring for chlorine and sewer bacteria.

I typically recommend drainage repairs when foundation movements are moderate or severe. I also correlate drainage issues with the floor elevations. This kind of evaluation is described in explained in a blog with the title:   Investigating Slab Foundation Failures in Central Mississippi.

How to Find your Family Tree with Ancestry DNA

This blog is about the Ancestry process using DNA that you can use to expand your family tree when you have hit a brick wall or a dead end from genealogical records. It was updated on 8-12-19 on 9-29-2019  and again on 12-4-2019. If you follow this process you could discover an error in your tree or expand it past all known records and then maybe you can become the Einstein of your family genealogy. Now I am assuming you were not adopted, so you know your parents and grandparents. If you were adopted the process is different. In this case, you start with your match list under the DNA tab at the top of the main Ancestry page. This is a list of your closest cousins. This list also shows the size of their family tree. So if you were adopted you begin by looking at the trees of your closest relatives. I will discuss this process in more detail at the end of this blog otherwise, please read on.

After working on my family tree since 2016, I still had two 2nd great-parents without any known parents. Breaking out of this deadlock to me was a huge and exciting advance in the genealogy of my family. In my case, there was a popular family picked by my other Ancestry cousins as the next or the 3rd generation. But no DNA evidence or records surfaced that supported this theoretical expansion of our family. I did not realize that Ancestry was telling us in a very indirect way that our theoretical next generation as we thought was almost certainly wrong. If you have expanded your family tree in error then Ancestry DNA has a way of telling you of your error. You simply have no DNA matches with the part of your tree that is in error.

In the last few months Ancestry has made some improvements that helped, but breaking through came only with a better understanding of how Ancestry was processing my family tree. What I realized was that if I could correctly guess either one of my 3rd great grandparents then there is a very good chance that Ancestry DNA would in-time verify my guess by showing new DNA matches with other cousins related to my new theoretical great grandparents. But the trick is, that if you guess wrong you must abandon that guess if you get no DNA matches with your new theoretical great grandparents. When you guess wrong it is like removing the DNA engine from your car; in-effect Ancestry can no longer help you. This is because Ancestry is trusting your research and attempting to verify it with DNA matches. How long does this process take? I don't really know, but for me, it took about a month for DNA matches to appear once I made a correct guess. An important point is that if you get just a handful or less of DNA matches eventually more will probably appear. This may happen because of improvements in processing or by the addition of new DNA Ancestry members. This is an area where you can help Ancestry by verifying the DNA matches that are flagged "evaluate," These are DNA matches that might be wrong. There is no single tree that makes the connection or used trees have conflicts or possible errors. So here your job is to work your way down as far as you can to your cousin in your tree. This process could help Ancestry find additional DNA matches. Once you do this the "evaluate" flag will eventually go away.

Ok, let's back up a bit. First, before you go this route you need to be sure you have exhausted all your genealogical resources. This means that you have looked in detail at the last known family. This includes all the children as well as the parents. You have no duplicate people and you have a family history up to your dead-end that makes sense.

A lot of times you find one or more children who were born out of the area that the parents were known to have lived. These should be deleted. Be sure all the children were born within the childbearing age of the parents. Once you have done all these it's time to move to the process below.

Ancestry requires 3 things to do what I am talking about. You must make a family tree up to your dead-ends, then you must correctly guess your next generation of grandparents then you must also take an Ancestry DNA test and allow time for Ancestry to process your data. This process should work in most cases out to about 5 or 6 generations or maybe a bit farther. Now we must understand that there may be smaller families of our ancestors who have descendants that have not taken DNA tests. So in these cases, this process might fail. But in order for this to happen, you may need to have 2 or more back-to-back generations with only 1 or 2 children that also had children. Now one last point: how do you guess the names of your missing ancestors?

I start by using the last name only of the last known father. Then I assume he was 20 years old when he had your grandparent. Then I begin searching, changing and adding possible information. As I progress I add to the age in 4 or 5-year increments. Next, I start guessing the state where your ancestor died. Next, I start guessing the state where my ancestor was born. As I progress I make a list of possible ancestors. Start with the state where your known ancestor lived and then progress to adjacent states. When you pick a possible parent, be sure that his age is realistic.

Finally, I  think you know for sure you have discovered your true lost ancestor when you get multiple DNA matches with your new ancestor. The best way to see these is through Ancestry's new ThruLines tool. You have to enable this from the Extras tab in Ancestry (select Ancestry Lab). This tool works out to your 5th great-grandparents. I access ThruLines from the horizontal family tree. Basically, this is a list of DNA descendants of your ancestors. This tool will patch together several people's family trees to show you how you might be related. To be sure this is a DNA match you need to add this person to your tree by working down from the common ancestor. Now if you only have 1 or 2 matches with a theoretical new ancestor you still might be wrong, because it may be that you are really related to these DNA cousins through some other unknown route. Also, note that you may have dead ends in your tree and not realize it. If you built any part of your tree by borrowing other member's trees, you need to use ThruLines to verify your whole tree out to the 5th generation.

Before I conclude there are some good rules to follow when you use Ancestry. You can borrow or import families from other people's trees. But when you do this be selective. I pick the 2 best looking family trees. These are trees with a lot of records but also trees without obvious mistakes like double people. If you import double people by mistake (and you will - do this) you simply merge the 2 people together. Once you import a family, try to verify it with a census, birth, and death records available in Ancestry. Finally, it's easy to forget that you have made a guess about your tree at some point. To help you Ancestry has added TAGs that you attach to a person that indicates to you that this person is a hypothesis. Also, add a comment to the person to tell other cousins what you are doing.

IF YOU WERE ADOPTED

If you were adopted your family history is inverted. From your DNA match list, you know the name of some distant or maybe a close ancestor. So instead of having a family tree, you have some ancestor that you are related to. So you must work from this person down to you discovering all the children of these known ancestors. You are a descendant of this person and if a thorough list of descendants is made you and your parents will appear in this list. You need to carefully watch the TV show "Long Lost Family." This show is sponsored by Ancestry.com. The hosts of this show were adopted themselves and they do the detective work using DNA to help people reunite with their DNA parents. In this show, they emphasize that you need to work with all the information that you know about your parents and your adoption process. On occasion, the breakthrough comes from a long list of possible family aunts or uncles that are contacted one-by-one on the phone. But if you are lucky, one of your parents or grandparents have taken an Ancestry DNA test. So, in this case, your closest DNA match could be one of your parents. I highly recommend that you in your Ancestry profile explain that you were adopted and tell the community your closest known DNA cousins. If you would like to have assistance please contact me.


Note if you see an error in this Blog please do not hesitate to contact me.