Difference between revisions of "Redrawing Parcels"

Parcels were originally created by tracing over paper maps with a digitizing tablet. Many of these original parcels shapes remain and are easy to spot for their not-straight lines and disagreement with the aerial imagery. DCAD's parcels are of similar quality. It's ideal to redraw full blocks of parcels. If DATE_EDITE for the parcels is older than 2013 then there is probably room for significantly improvement.

Traverse Tool

This is the tool for entering metes and bounds. When you enter a full circuit in the traverse tool you can check the "closed loop" box and then click the "Closure..." button, which is extremely useful for checking if you mis-entered any numbers. If the values for "Misclosure as X/Y" are greater than .01 feet, double check your work. Then click the adjust button and hit ok so that it will adjust all of the metes so that the start and end point match. This feature only works if you create the whole thing with the traverse tool, which is sometimes difficult, but it's very useful for catching data entry errors.

Plats

If ABSTORSUBN doesn't start with an 'A', check the ABSTORSU_1 field and look up the plat in the Utilities Laserfiche under Design > Plats. Start with the newest and work backwards until you've entered all of the subdivision that is in the block you're working on.

Enter the plat and block boundaries as temporary parcels, then redraw the parcels inside of it. A plat boundary is the only part of a plat that is certain to have complete measurements, including full descriptions of any curves. These temporary shapes then serves as a framework that makes filling in the individual parcels easier.

If you are entering a plat boundary, you might not want to adjust it because then all the parcels will be 79.998' wide instead of 80'. I prefer to delete the last mete after checking the closure and then finish the shape instead of adjusting it. This will concentrate all of the mismatch in a single parcel, so it will be 79.9' and all the rest will be 80'. I'd rather have more parcels be exactly to spec than have all the parcels be equally off. It's personal preference, really, so don't worry too much if this isn't making sense.

Deeds

For parcels with an abstract for their subdivision, do a property search on dcad's website using PROP_ID, view the details, then hit end to scroll to the bottom where there is usually a Deed section. Instead of going back to the search page and clicking through to the details every time, you can just replace the number at the end of this URL : https://www.dentoncad.com/index.php?option=com_content&task=view&id=100&PropertyID=173423

Next go to the county clerk's document search site (http://216.60.44.147/TX/Denton/D/Default.aspx) The first dropdown should have "Real Property" selected. The document will be referenced in one of two ways:

Document Number

Ex: "2014-92284" Select "Document Number" from the second dropdown, enter "92284" and search, then click the result from 2014.

Volume and Page

Ex: "1034-678" Select "Volume/Page" from the second dropdown, enter "1034" in the first box, "678" in the second, search, and there's usually just one result to click

Then you have to click the "View Image" tab above the document info on the right. The metes and bounds of the tract are usually on the last or second to last page.

Use the newest and work backwards if necessary until you find a readable document with a good description. Sometimes metes will have errors introduced when they are copied to newer deeds, so if a shape is not closing well, check older documents for differences.

Fitting Everything together

When you're done redrawing each individual plat or deed you'll be left with a bunch of parcels that don't neatly fit together. The parcels will need to be rotated to fit together and some of them will need their geometry tweaked. Use the most accurate parcels in the block as a base. The most accurate will be ones that were recently GPS'd. The least accurate will be handwritten and use varas instead of feet.

The first step is to rotate parcels so they have the same orientation. When one document says "N 88-49-50 E" and another describes the same segment as "N 87-56-14 E", you'll need to rotate one. There is an excel spreadsheet set up as a Rotation calculator. This is a bit cumbersome, hopefully future versions of ArcMap have a better rotate tool.

When you have everything rotated the same, things will still not fit together. This is the difficult and frustrating part. Start making judgement calls and moving vertices around, but try to limit the number of times you change any given parcel. If you move a vertex half a foot to match an adjacent parcel, that's not a huge deal, but if you keep coming back and moving it another half-foot then the accuracy will start to take a real hit.

Rotating a feature is non-destructive of the basic geometry and necessary for almost every parcel, so try to get things to match as closely as possible with rotations before doing the final step of adjusting individual vertices.

Now symbolize the parcels as just a thin black outline and turn off all other layers. This will let you see where you have mismatched vertices on boundaries between parcels. These lines will appear thicker in places because they will alias differently due to not being perfectly identical. Add and adjust vertices until it looks clean.

Save periodically if you're working on a large block. When you're satisfied with a block, delete any temporary features you made in the process, commit the changes, then export the block and send it to DCAD so they can benefit from your improved parcel geometry. This means you need to improve on DCAD's parcels for this to be worth doing.

General Notes

• The older the measurements, the more they need to be corrected by rotating them counterclockwise. Newish stuff often needs rotating a little too.
• Sometimes GPS coordinates will be wildly wrong. Coordinates from 2013 and later seem to be accurate