1. Eric Loecher GIS Specialist Linn County, Iowa
Parcel Genealogy
Eric Loecher
GIS Specialist
Linn County, Iowa

2. What are the goals of Parcel Genealogy?
To keep track of changes to parcels
A digital archive for faster researching
A way to keep track of how many Geo-Referenced Parcel Numbers (GPN) are deleted each real estate year
Keep it simple.
How many times a week do you get a call asking what did this parcel come out of? We get quite a few calls a week. This will hopefully allow us to answer those questions faster.
We also wanted to think how this could be helpful for those people who use transfer books.
Every year, we count how many parcel numbers have been deleted and how many numbers have been added to our system.
Keep it simple…Consider the person or workgroup is going to maintain the data.

3. Things to Consider Who is going to maintain the data?
What is going to drive the data?
Access or ArcGIS?
Maintenance: It needs to be quick and easy.
Simple copy and paste operation with little data entry would be ideal.
Maintenance: We have five possible editors.
So we’ll need to make this something many people could use at once. Access is great if you have one person. Since we have at least two people making changes all the time, ArcGIS and SDE allows more editors.
I didn’t want to make this painful.

4. Maintenance and How this works for our Editors.
Solutions:
A simple copy and paste the retired parcel into the new layer.
Little attribution as possible. Keep it Simple!
Using domains to reduce typing and errors.
Less key strokes the better.

5. Geodatabase Design Created a polygon layer in ArcSDE. Fields: GPNNUM
BOOK
PAGE
RECDATE
REYEAR
REASON
Domain: Subdivision, Plat of Survey (P.O.S.), Spilt, Combination & Condo
GPN is our parcel number
Book and Page of the recorded document are entered.
RECDATE is the date of the recorded document.
REYEAR is the real estate year when the change happened.
REASON explains what caused the change.

6. Example
This is an overview of my work area in Robins (north of Cedar Rapids).

7. The green hatched areas represent a new subdivision
The green hatched areas represent a new subdivision. Usually, I like to draw my new plat in first to see which parcels will be affected.

8. I copied the parcels into the parcel genealogy layer and attributed them with the plat information. Any parcels with a remaining acreage will have a new GPN number assigned to it.

9. Using my construction layer and topology tools, I created and attributed the new parcels.

10. Now, if you identify the Parcel Genealogy layer, then it will drill down through the polygons in this dataset. This allows you view the lineage of an area.

11. Thinking Forward How can the data be made better?
Include Deed Holder Names
Include Right of Way Acquisitions
Linking Worksheets with the Data
Time
Technology
Other layers of interest:
Annexations
Current Subdivision Layer
History Spatial Databases
Names would be helpful.
Right of way acquisitions is now in the works.
Attaching worksheets to see a digital paper trail.
Time will make this much more helpful.
Technology: New methods to manage history: New real estate system or SQL Server 2008 with managing spatial data.
Annexations have been helpful in researching. We also break this down by real estate year. It allows us to see what parcels were annexed along with the recording information.
The Current Subdivision layer is helpful because of the book, page and date information. It gives a starting point for a particular subdivision.
Historical Databases: These are basically just a snap shot at the end of a real estate year.

12. Questions, Comments or Concerns
Eric Loecher
GIS Specialist
Linn County GIS
Phone Number: