1. Pima County Parcel Fabric - Tips for Staging and Loading Parcels
Thank you for your attendance and your willingness to allow me to share some Tips for preparing and loading data into the Parcel Fabric. My process relies upon familiar tools for parcel fabric development, but facilitates the Parcel Fabric development in sequence with existing GIS parcel data processing.
Presented By:
Jack L. Avis, PLS , GISP
AGIC 2017

2. Quality of your Source parcel data and its GIS usage
What type of Source data do you have CAD or GIS
Close examination of exiting CAD or GIS layers
Clear understanding of how the Source data was created
Is the data used to support the existing GIS Enterprise.
As with any migration a clear understanding of how your Source CAD or GIS data layers are used is vital to your migration process.
Your CAD data may contain several CAD layers that can be transformed into not just Parcels, but Public and Private Roadways, Easements, Common areas, and Public Land Survey System Boundaries.
How your source data was created is important, was it digitized, or create using Coordinate Geometry?
Identification of a source for Parcel IDs is vital to the parcel fabric development process.
Your migration process will likely take several months, so you will need to consider what impact this may have on existing enterprise resources and GIS applications that rely upon existing GIS Parcels.
AGIC 2017

3. Categorization of Parcels by Type
Use of the Local Government Information Model (LGIM)
PLSS, Tax Parcels, Subdivisions, Lot & Units, Encumbrances
Type
Description 1
PLSS Township 2
PLSS Section 3
PLSS Quarter Section 4
Special Survey 5
Simultaneous Conveyance 6
Conveyance Division 7
Tax 8
Ownership 9
Encumbrance 10
Separated Right 11
Other 12
PLSS Second Division
Sublayer
Parcel type
Historic Parcels
Type = 7, 9, 6
Cadastral Framework
Type = 1, 2, 3
Subs and Condos
Type = 5
Tax Parcels
Type = 7
Lots and Units
Type = 6
Encumbrances
Type = 9
The Parcel Fabric data model is a collection of parcels that are classified by Parcel Type or use. We found that our CAD data had a few basic types of land parcels that we could load. (Click)
Tax Parcels will be the majority of what you will be loading from your source, but other parcel types may be available or identifiable from other sources, such as subdivisions, floodways. (Click)
The Parcel Fabric data model supports common workflows, and specific parcel editing tools for maintenance of the Parcel Fabric and including tracking of parcel history.
A quick comment on ROW as Parcel Type, ESRI recommends that ROW parcels be loaded separately or not loaded at all do to there complexity. Unless your data is coming from very clean cogo line work, segmentation violation errors will occur when loading.
We were able to create a separate feature class of our public ROW as part of our migration process.
AGIC 2017

4. Public Land Survey System (PLSS) and Control Layers
PLSS Framework as a Parcel Type
GIS Section Conners as Control Points from source & Surveys
Sets the stage for future Parcel Fabric Adjustments
Because our CAD Parcels are maintained as (9300) individual Public Land Survey Section level drawings we were able to capture the PLSS boundaries and the End Points of these boundaries as GIS Section Corners (GISSC) points shown as Gold Triangles. Each have a Unique Identification.
(Click )Having the GISSC as a starting point for adjustment of parcels is important. When we find the our GISSC source differs from Field Survey positions of the PLSS Section Corners, this will allow for adjustment process to be used. Resulting in a better spatial position and “Self healing of parcels” This adjustment can be used when working in areas were poorly positioned source data is know or discovered.
In this control adjustment example the digested GISSC points differ by several feet from the true Section Corner position, providing us with the potential to improve the spatial position and graphic representation of these parcels.
AGIC 2017

5. Processing Tools & Topology Rules
Create a Work Plan, then Modify, and Adjust as needed
Automation of data migration process using Models & Scripts
I don’t expect you to read thought this Work Plan, but instead want you to think about the bigger picture here.
A good work plan is evaluable as you develop and adjust your Parcel Fabric data migration process. Its also serving as source for your metadata for recording your processing steps. Simple put migration can be a complex, but doable process with a plan.
Here are a few key components of our plan: Our CAD data is edited and used on a daily basis, so the key to our migration process was to develop nightly parallel processing with two Parcel Fabric QC steps. (Click)
Outlined in the gold box there are several processing Tools and Steps that are automated. We utilize AutoCAD and SQL Server to track daily CAD edits, followed with Python scripts and models to process the daily CAD edits and assemble these edits into Township level feature classes ready for loading as edits occur each day.
Also, we are able to produce a complete County wide GIS parcel feature class from the 278 Township feature classes each day to support or Enterprise GIS parcel needs. Outlined in the green box
Meeting the enterprise's parcel needs allows us to continue to work toward our ultimate parcel fabric solution. It also allows for training staff in parcel fabric editing tasks, by migrating and batch loading of several Townships at a controlled pace outlined in the blue box.
AGIC 2017

6. Processing Tools and Add-ins
Tools for cleaning up Multi-Segment Lines
Curves and Lines (Add-in)
ESRI has provided several processing tools to aid in the cleanup of your source data prior to loading. If your source data was digitized then you likely have Multi-Segmented Lines. Multi-Segmented lines are lines with multiple vertices combined along lines and or curves.
If your Source is made up of clean COGO line-work then you will see far fewer multi-segmented lines.
The Parcel Fabric expects the lines and curves to have a single beginning and ending point for each segment.
The Curves and Lines Add-in tool bar is very helpful in identify and cleaning up multi-segment lines. It allows you to split these segments into individual lines and curve segments.
AGIC 2017

7. Processing Tools and Add-ins
Cleaning up Multi-Segment Lines
These tool allow you to select the Multi-Segment lines or curves within your extents and perform an cleaning action. (Click)
They allow you to specify lateral offsets and minimum distances for cleaning up combined line segments. (Click)
You can also work with curves separately and fit a curve based upon the known quality of curves in your source data.
By using these tools you will improve you’re the quality of your pre-parcel fabric data and prepare it for applying the required Topology Rules (Click)
AGIC 2017

8. Required Topology Rules and Validation prior to Loading
[Line feature class] Must Be Covered By Boundary Of [Polygon feature class]
[Line feature class] Must Not Self-Overlap
[Line feature class] Must Not Self-Intersect
[Line feature class] Must Be Single Part
[Line feature class] Must Not Intersect Or Touch Interior
[Polygon feature class] Boundary Must Be Covered By [Line feature class]
Script your Topology Rules, Validation process, & Reporting
These required topology rules prepare the Parcels to be loaded into the Parcel Fabric. If there are any topology errors in the polygon feature class the parcels can not be loaded into the Parcel Fabric.
As you prepare and organize your parcel data, I advice you to scripts the topology rules and validation process as a QC step, for reporting any errors prior to loading. Your data can then be staged at the Township, or subdivision level containing between 20,000 to 40,000 Parcels for batch loading.
Only consider automating the batch load process for those areas that are assembled, cleaned, and topological validated.
AGIC 2017

9. New Parcel Fabric Tools
During the last year ESRI has released a number of new Tools related to the Parcel Fabric. These tools are not part of your standard ArcGIS install package.
The Link at the top of the slide will take you to a download and Install site explaining how these Toolboxes can be added to the ArcMap Toolboxes.
There are a several helpful Scripts here that you may be able to take advantage of. With the potential to customize and prepare your Parcels for loading. I our case these scripts have come a bit to late as most of our automated processes were in place at the beginning of this year.
The take home message here to investigate these tools and other tools for automation were it meets your needs for the initial data migration from CAD or Feature Class to the Parcel Fabric.
AGIC 2017

10. Develop Process to Track Parcel Changes
Allows for a phased transition and staff training
Part of our shared responsibility with the Assessor’s Department is the tracking of daily edits and adding them to our Parcel Fabric as part of our phased transition.
Here we are able to take advantage of nightly processing where we can identify the recent splits in CAD coming from the Assessors. The single dashed red line exists in our GIS feature class for Parcels. Along with the parcel codes used for the split in the table shown at the bottom. Click
Parcel Fabric Editors can add the new split by using one of the ESRI pre-defined Parcel Split Workflows. (Read)
AGIC 2017

11. Take Home Messages
Get to Know your source data strengths and weaknesses
Identify and load sources parcels by parcel type
Devise a Work Plan for the migration processing steps
Plan for the GIS Enterprise’s parcel needs while transitioning to the Parcel Fabric
Automate steps from source data to the Parcel Fabric
Use Parcel Fabric Tools & Add-ins to clean lines & Load Data
Create environment for staff training Parcel Fabric editing
Devise a plan for tracking parcel splits & use ESRI workflows
AGIC 2017

12. Thank you! Are There Any Questions?
Contact:
Jack L. Avis, PLS, GISP Pima County, Arizona
AGIC 2017