CCMA ARTICLE


CAD vs GIS


In June 2004 Kim Ballachey, a Cadastral Mapping Technician II at the Sonoma County Assessor’s Office, solicited advice and opinions from other counties regarding their use of AutoCAD versus ArcGIS software products for cadastral mapping.

The questions were as follows:

1. Is your GIS parcel base accurate enough for you to update and maintain your Assessor’s parcel maps?

2. Who created your Assessor’s parcel layer for GIS?

3. Are you still using AutoCAD? If so, what are the reasons?

The 21 responses below may have been edited for clarity, spelling and grammar, and although I’m not an English major, I’m a pretty good spellerer. Each response represents the sole opinion of its author, and any references to private companies, consultants or contractors also reflect the sole opinion of the author.

This article was compiled and edited on August 4, 2004 by Jim Isbell, Engineering Technician II for the Kern County Assessor’s Office.


ALAMEDA COUNTY

We just signed on a contractor to convert our CAD base map data to an ESRI format, and thenceforth we will work in that new ESRI environment. There are several existing base map databases available to us, once we begin conversion. We have never used AutoCAD. The new system will be highly customized to look and feel like our current GDS CAD system, but with the power and versatility of the new ArcGIS 9 system. It's just the very beginning of a huge change for us, so I can't contribute very much constructive information. Good luck.

By: John Thomson, Mapping Technician III


ALPINE COUNTY

Our GIS parcel base is not very accurate, due to stretching (rubbersheeting) of the parcel base. Most of it was created from the AutoCAD map drawings. We are still using AutoCAD to maintain the integrity of the parcel maps.

By: Donald O’Connor, Assessment Office Specialist


AMADOR COUNTY

I created Amador County’s GIS Assessor parcel layer. It is not accurate enough to use as our Assessor parcel maps, nor does it have enough detail. I digitized the base map and rubbersheeted parcels to section corners, initially. Now, as I process recorded maps, I adjust the parcel lines in the changed areas to align with road centerlines (from GPS) and aerial imagery. We did not have any of that when we first digitized the parcels.
Yes, I am still using AutoCAD for our Assessor plat maps. Yes, I make the changes twice, however, the GIS is only parcel lines, with no annotation. We use the Autodesk MapGuide products for our GIS. It does all the things the ESRI products do, but our county uses Megabyte, and the Autodesk products link directly with Megabyte. Data updates are available immediately.

By: Denise Tober, Cadastral Drafting Technician II


BUTTE COUNTY

We have entered maps entirely from recorded information, so yes, our maps are definitely accurate enough to update and maintain. We have also “rubbersheeted” maps together to form a county map.
We have pretty much created our own parcel base, one map at a time. We still have a thousand or so maps that need to be converted, but we do them on demand or as time allows, and this has worked very well in our situation. We concentrate on converting “hot spots” for development within the county, and do the rest during the “lulls”.
We are currently using the 2000 release of Autodesk Land Desktop with the Survey and Civil Design programs. Since we started with AutoCAD (due to the fact that ESRI was not accurate enough for our needs at the time), we have simply continued with it because all we have to pay for is the upgrades every three or four years. I have not kept up with the ESRI products over the years, but AutoCAD serves us VERY well and is extremely accurate and easy to use. We do have an old version of the ESRI product and did not find that it was as user friendly as AutoCAD and seemed to have a higher learning curve. The newer versions of AutoCAD have proved to be tailored specifically for the mapping industry and have been very easy to learn and incorporate into our workflow. We also weighed in the fact that most other counties were also using AutoCAD and that it was easier to share information, programming and learning tips with other counties. It is also the preferred programming for the State and for our own Planning and Roads departments, so there are the ease and compatibility factors, all over again, with them.

By: Dorothy Balaz, Cadastral Drafting Technician


CONTRA COSTA COUNTY

The Assessor's GIS parcel base map originated as the Contra Costa County Public Works base map, which was maintained in MicroStation. In 2002, it was converted into a GIS format by our consultants, Vestra Resources, Inc. of Redding, California. Over the next year, the GIS base map was "cleaned up" to more accurately reflect information found on the Assessor's parcel maps. Updates and maintenance of the Assessor's parcel maps is now performed on both the GIS layer and the MicroStation drawings. We still use MicroStation to create separate Assessor's parcel maps in addition to the seamless GIS parcel layer.

By: Lynette Stone, GIS Intern


KERN COUNTY

Our GIS data is, we feel, not quite ready for prime time for use in published assessor maps, but we have acknowledged that is the future direction we want to go in. We would love to make our assessor maps with ArcGIS, but there are a few pieces still missing from our puzzle. Actually, there are areas where we could test the idea; we just need to find the time to experiment.
We created our own parcel dataset in 2001, using data from two sources: the City of Bakersfield GIS parcel dataset, and the Valley-Wide GIS Project parcel dataset completed in 1998. We have cleaned up the data and continue to maintain it in ESRI shapefile format. We still produce the Assessor’s maps with AutoCAD.
We use a combination of Autodesk Map, ArcView 3.2, and ArcView 9.0. Our AutoCAD and ArcView 9 licenses are on subscription/maintenance plans, so we always have the latest versions (although we don't always upgrade immediately upon receiving them). We use each product for fairly specific purposes, leveraging their respective strengths. We also utilize custom programming and scripting, so our productivity is enhanced, while still using off-the-shelf (standard) solutions, and avoiding third-party packages.
We find AutoCAD is still a strong tool for editing geometry, and it imports and exports shapefiles fairly well. It's our "old reliable." We don't know if the Assessor will ever spring 19 grand per seat for 5 seats of ArcInfo (doubt!), so we use what we can convince them to buy, and for editing geometry, it's got to be either AutoCAD or ArcInfo. If you have ArcView, you probably know how inadequate its editing tools are. And I'm not familiar with ArcEditor, but I have a gut feeling that it may not be worth considering for the long-term job we are faced with. One of our main concerns is using software AND procedural solutions that make sense for the long-term. For this reason, we are wary of even ESRI products, and hope to see the ArcGIS product development become more stabilized. As you may be aware, ArcGIS is built on the development framework known as ArcObjects, which is Component Object Model (COM) architecture. But at the same time, Microsoft is now abandoning COM in favor of its Dot Net (.NET) framework. In spite of Microsoft's claims that .NET is compatible with COM (for now), we hate to see such a departure, and are forced to wonder what the future holds for COM-based products, unless Microsoft continues to support it.
NOTE: Shortly after writing the previous paragraph, I have since come to realize that ArcGIS 9 now has a development interface for Microsoft’s .NET framework. After a brief review of the documentation provided, however, there is a stated caveat that developing with .NET could possibly have a negative performance impact, due to an additional layer of program interpretation built into the .NET framework. It appears that .NET is compatible with COM, but only because of a framework component that maintains this “bridge.” My earlier evaluation remains the same, however. The architecture of ArcGIS seems to be founded upon a technology that has a dubious future, or at least it seems that way for now, pending further research. I admit that AutoCAD fares a similar fate with its VBA interface, but AutoCAD also incorporates AutoLISP as an internal product component that does not rely on Microsoft or any other outside support, and AutoLISP is used almost exclusively for customization in our shop. Also, Autodesk has shown a solid willingness to continue supporting AutoLISP indefinitely in its products.
So for now, we also continue to use AutoCAD for our published Assessor’s maps, as well as editing geometry, and we will watch with a wary eye towards ArcGIS, waiting for stability we can trust for the long haul. At the same time, there are still some functions that are easier and faster to perform in ArcView 3.2. ArcView 8/9 is great for general viewing, overlaying, and auto-labeling, but a few things changed drastically enough that I now have to learn to program (using ArcObjects) my own custom tools to do the same things that were built-right-in to ArcView 3.2. These specific issues are few, however, and are caused largely by the methods I've developed, i.e., the way I use the software's features to accomplish my tasks. I feel that ArcGIS is a far stronger product overall, but now I must develop new procedures and programs to do the same work, using a far more complicated platform.

By: Jim Isbell, Engineering Technician II


LAKE COUNTY

ARE YOU MAINTAINING AND UPDATING YOUR ASSESSOR’S PARCEL MAPS IN THE GIS PARCEL LAYER?
Yes, I am. I update it and then export it to the IT Department, where the GIS Specialist puts it out to the intranet, where the other county departments can view and make copies of the updated map. I update the map, and then Lon updates the CPL layer.
IS YOUR GIS PARCEL BASE AS ACCURATE AS YOUR PREVIOUS ASSESSOR MAPS?
Yes, with ArcGIS 8.3. It has the capability to enter COGO distances and bearings, whereas the ArcView 3 version didn't really have that capability. We wanted something that was accurate, and this works well. Actually, our maps look really good, once updated. The old vellum maps - which have been scanned - aren't as nice, but the old CAD drawings still look great.
WHO CONSTRUCTED YOUR GIS PARCEL BASE?
Vestra Resources, Inc. They also customized it for us.

By: Kelli Brown, Cadastral Mapping Specialist


LASSEN COUNTY

We are maintaining the base layer map of the new GIS. At this time, because we feel that the accuracy of the GIS data is not consistent with our Assessor’s plat maps, we are maintaining both. Maybe someday, with a lot more time and corrections, we will go GIS all the way – it is amazing!
I understand that Orange, Lake and Los Angeles Counties are using only GIS. We contracted with Vestra Resources, Inc. at 963 Maraglia St., Redding, CA 96002. You can contact them at (530) 223-2585.

By: Carole Dustin, Senior Cadastral Drafter


LOS ANGELES COUNTY

IS YOUR GIS PARCEL BASE ACCURATE ENOUGH FOR YOU TO UPDATE AND MAINTAIN YOUR ASSESSOR’S PARCEL MAPS?
Yes, we maintain our maps using GIS. To be more specific, we created a geodatabase using SQL Server and SDE to maintain our parcel boundaries and polygons, TRA lines, and polygons from which we produce City boundaries and polygons.
WHO CREATED YOUR ASSESSOR’S PARCEL LAYER FOR GIS?
So far we have converted the entire County to a geodatabase, but only about 10% (out of 110,000) of our map pages are in digital form. We do not produce manually drawn pages anymore; everything is done digitally from our GIS base. If a job has to be done on a page that is still on paper, we convert the entire page to a digital one. So, our GIS base is always up to date, and our GIS-derived maps are being converted simultaneously.
ARE YOU STILL USING AUTOCAD? IF SO, WHAT ARE THE REASONS?
The GIS base was constructed entirely in our Mapping & GIS Services unit. We did not start from scratch, though; we used data already created by the Department of Public Works (not in GIS format, but as CAD files), since they had started their house-numbering maps for the unincorporated county areas, plus some contracted cities. We also took source data from cities like Los Angeles, Burbank, Alhambra, Glendale, Torrance and Long Beach. We did fill some holes, but mostly our main task was to standardize all those data sets, clean them up and update them. We finally converted them from thousands of CAD files into a single, seamless geodatabase in GIS format.

By: Emilio Solano, Supervising Cadastral Engineer III


ORANGE COUNTY

We do not use ESRI GIS software; we use Bentley MicroStation. The Orange County GIS database is maintained by the Public Works/Surveyor's Office. We are not part of it; we have inquiry access only. Our Assessor’s parcel maps are maintained independently of the county’s GIS system.

By: George Eachus, Chief of Mapping Division


PLACER COUNTY

Automated Mapping Services (AMS), from Carson City, Nevada, originally built our GIS base map. By the time the map was completed, it was nearly four years out of date, and we contracted with another company, Geographic Resource Solutions (GRS) to bring it more current and resolve some outstanding issues with the AMS work.
Because of the way the map was constructed, it has been used extensively to build and maintain the assessor map pages. While we are currently still utilizing AutoCAD to maintain the 11x17 Assessor’s map tiles, we are in transition to utilizing ESRI ArcGIS 9.0 to do much of this in the future. Our main reason for continuing with AutoCAD is that we still receive the engineers' and surveyors' drawings in this format, and it's easier to use it prior to importing the final drawings into ArcGIS.
For more specifics on the building of the base map, I would suggest you contact Mr. Ken Strump of GRS. We are very happy with the mapping he delivered and he will be very helpful if you are considering a transition from AutoCAD to ArcGIS. His phone number is (707) 822-8005 or you can email him at: grs@grsgis.com. In order to make sure we develop some efficient work processes and get some specific training to do the work that will be done by this department, we are in the process of hiring Vestra Resources, Inc. This company has already had some great successes with Calaveras and Santa Clara Counties and we are expecting the same. They can be reached at (530) 223-2585 or you can e-mail Dean Angelides at dean@vestra.com.

By: Gary Powell, Assessment Manager


RIVERSIDE COUNTY

We maintain and update the Assessor's GIS layers with our own mapping staff. Our GIS parcel data is as accurate as our previous Assessor maps, since most of our parcel layer was digitized from our manually drawn maps.
If I had to do it over again, we would have waited for the Survey Department to put in more survey data for street centerlines, section corners and monuments, so we could have tied our parcel layer to them for better control. We are now forced to go back and correct the GIS line work to be more accurate. Sooner or later, you will have an aerial photography layer, and you need to be able to overlay each, and they should match.

By: Doug Vierra, Chief Mapping Technician


SAN BERNARDINO COUNTY

Yes, we are maintaining and updating our Assessor maps in the GIS parcel layer. Our GIS parcel base is more accurate than our previous Assessor maps.
We contracted with ESRI to finish our parcel base map project. We started converting Assessor books into GIS format here in our office, but we just didn’t have the staff to complete it and still get our normal work done. The project should be done by April of next year.

By: Bret Keesler, Mapping Services Supervisor


SAN LUIS OBISPO COUNTY

IS YOUR GIS PARCEL BASE ACCURATE ENOUGH FOR YOU TO UPDATE AND MAINTAIN YOUR ASSESSOR’S PARCEL MAPS?
No.
WHO CREATED YOUR ASSESSOR’S PARCEL LAYER FOR GIS?
Barclay Map.
ARE YOU STILL USING AUTOCAD? IF SO, WHAT ARE THE REASONS?
Yes.
1. Lack of accurate base map.
2. Current workload/staffing.
3. Cost to migrate.

By: Steve Wolfinger, Cadastral Mapping Systems Supervisor


SANTA CRUZ COUNTY

The County of Santa Cruz, California established its GIS in the early 1990’s. The original system was based upon digitized Assessor’s maps, maintained in AutoCAD and housed on a mainframe platform. The data was distributed via mainframe applications and as shapefiles that had been converted from the AutoCAD files. The mainframe platform was not able to support the relational database functionality offered by new GIS applications, such as those developed by ESRI. In order to take advantage of the relational database technology and ESRI’s Geodatabase model, the County decided to change from the mainframe platform to a Geodatabase stored in a SQL/SDE database system. The conversion process began early in 2003 and is now near completion. This has not been a simple process, and we have had to overcome many obstacles. The base layer for the GIS system is the cadastral layer and our initial challenge was to develop maintenance and tracking procedures for the Assessor’s Office to replace the existing CAD-based editing.
This migration has been an interesting process, but definitely a worthwhile one. One of our major obstacles was not having any role models that exactly fit our mold, so we found ourselves spending a lot of time figuring out problems for which ESRI didn't really have any advice. For us here in the Assessor's Office, figuring out how to replicate the map pages probably took the most time.
We are now exclusively working in ArcMap and all our data is maintained in the Geodatabase. We are no longer doing any updates in AutoCAD, although the majority of our map pages are still in that format, but the data is being incorporated into the Geodatabase as we perform new maintenance.
I would be interested in hearing more about your migration plan and I would suggest that you come and take a look at our system if you are seriously planning the migration. We have a lot of documentation that we have produced along the way that we could share with you. I don't know if you are planning to move your data into a Geodatabase, but I am also attaching our cadastral data model in case you are interested.
We would like to share our experiences with the GIS community and address the challenges and issues that we have faced and discuss how we have resolved them. A presentation that we have prepared may be of particular interest to organizations that are planning to manage and track their cadastral data changes in Geodatabase as well as other groups that are interested in the Geodatabase migration process. Our presentation focuses on our migration strategy, Geodatabase design, data maintenance procedures, and future goals. We also discuss how this new system is able to meet the needs of an increased number of County departments.

By: Gulla Gisladottir, GIS Analyst


SHASTA COUNTY

IS YOUR GIS PARCEL BASE ACCURATE ENOUGH FOR YOU TO UPDATE AND MAINTAIN YOUR ASSESSOR’S PARCEL MAPS?
Yes; we use Autodesk's Land Development Desktop to query features in and out of master drawings to sub-drawings. We have a parcel base keyed to assessor map books that we maintain our Creation features in; we then query new or changed features into our Plat drawings, and then to our Topology drawings. The Creation dataset retains all of our parcel creation history, notes, record links and reference features; the Plat subset contains plat information (templates, bearings, distances, lot numbers and parcel numbers, etc.) for plat maps, and the Topology subset contains closed polygons with their associated attributes for shapefile export.
WHO CREATED YOUR ASSESSOR’S PARCEL LAYER FOR GIS?
We create and maintain our own parcel layer, although we did obtain much of our source data from local resources, such as cities and other agencies. We have problems with some of these datasets.
ARE YOU STILL USING AUTOCAD? IF SO, WHAT ARE THE REASONS?
Yes, we are still using AutoCAD for many reasons:
1. ArcGIS/ArcEditor requires a much steeper learning curve. We already know how to use AutoCAD, and we don't want to lose any productivity while trying to master a new software package.
2. The AutoCAD Land Development package comes complete with automated routines for parcel creation and plat map development. ArcGIS requires add-on packages like Novalis's Parcel Editor and ArcPublisher at additional expense and maintenance schedules.
3. AutoCAD is still the best platform for entity creation. Out of the box, it has 10 times the functionality of ArcEditor. You can run command-line routines (one or two keystrokes), easily customize your own toolbars, routines, templates, blocks and profiles. All of our old LISP routines are easily transportable.
4. Availability of custom routines. ArcGIS 9 is still a very new product and although a very good product, not much has been developed in the way of automated/custom tools to meet specialized needs such as ours. AutoCAD has a ton of available and sharable routines.
5. There are more available human resources for AutoCAD than for ArcGIS. The community college turns out 8 times as many CAD users than ArcGIS users, and the ArcGIS users tend to prefer making colored maps and kind of miss the concept that in order to print these maps data must first be created. Hopefully, your local college is different. As a whole, good ArcGIS users are hard to come by, yet it is fairly easy to find a number of people who are fairly proficient with AutoCAD.
6. It is cheaper to use what we already have in place. For our office to upgrade to the ArcEditor/Novalis/ArcPublisher suite, we would be looking at $9,000 per seat, $2,000 per year per seat for maintenance, and training at $3,500 per person, if done locally. Considering the state’s budget and ours, many feel that that kind of money could be better used elsewhere.
7. From the demonstrations I have seen for Novalis's Parcel Editor, I can enter coordinate data much faster using the AutoCAD ten-key data entry commands, compared to using the awkward screens provided by Novalis, allowing us to complete parcel maps in a fraction of the time.
8. We would have to convert all of our plat maps from AutoCAD drawings to ESRI projects.
Don't get me wrong, we use the toolbox approach, the best tool for the job; ESRI has a very nice software suite for GIS, but I feel it presently still lacks for data acquisition/capture functionality. We have both AutoCAD and ArcView (not ArcEditor) in our office, and my people, by far, prefer AutoCAD over the ESRI suite (we have all seen the demos and have been to numerous workshops for both products) and get much more done with AutoCAD. We are very slim on staff so we need to use what will keep us the most productive. We can also easily switch between the two products by using shapefiles, which are still pretty much universal. I know that ArcGIS will continue to improve, as will AutoCAD.
Our other county departments are pushing for exclusive use of ESRI products. The new ESRI maintenance fees really threw us for a loop, so we are scrambling to come up with monies to keep both products in our office. Currently, I am in charge of a committee investigating the use of concurrent licensing for ESRI products for the entire county. We are looking at 10 floating licenses for ArcView, 2 for Spatial Analyst, 2 ArcEditors, 3 Publishers, and keeping our AutoCAD seats for data capture. This will work for most of our departments since very few are running ArcView all the time. Then, we will re-evaluate after a year.
Autodesk and ESRI both have excellent products, but they are still apples and oranges. There are pros and cons for both platforms. AutoCAD is still far and away the best product for data entry and production maps, but seriously lacks for GIS functionality and analysis. Personally, I like both products for different reasons, and yes, I would like to see everything rolled into one package (sure would make my life easier). Most of the counties in the state seem to be moving to ESRI, and that may be primarily the result of management decisions, but I don't think they (management) really look at the productivity issues, just the “big picture” with GIS. As we continue to move from entity creation to performing more analysis, we will most likely migrate to the ESRI suite over the next 2-5 years. Our biggest constraints will be money and conversion; we have a lot of historical data and data links that won't come though with a simple conversion. We will take our time and most likely bring up one seat at a time and make a gradual transition. This way we can still keep our productivity and the transition won't be too much of a shock to our small department. The way I see it, this conversion will not only pad my resume, but it will also increase my income. Like I said earlier, good ArcGIS users are hard to come by.

By: Ken McKrola, Program Manager


SISKIYOU COUNTY

Yes, our county does have a GIS parcel layer created. However, it is not as accurate as our parcel plat maps, so we do not rely upon it for our work. The parcel layer was created by the Planning Department. They created it by scanning our maps and then rubbersheeting them together. The entire GIS site is maintained by the Planning Department.
We are still using AutoCAD (Land Desktop 2005). Due to our investment in AutoCAD, our Assessor has made the decision that we will continue creating and maintaining our maps in an AutoCAD environment. With developing technologies, future ESRI/GIS software may be utilized.

By: Jeff Clausen, Senior Cadastral Mapping Technician


SONOMA COUNTY

We have a GIS parcel base, but it is not accurate enough to update and maintain our assessor parcels maps. It has been "rectified" to visual features observed in our orthophotos, and has inaccuracies of 50+ feet in some areas.
It was originally created in our Permit and Resource Management Division, using 500' scale planning maps, and rubbersheeted to create a "seamless" map. It has since been taken over by our GIS group, who has compounded the error in the parcel base by "rectifying" it again to what they see in the orthophotos.
We still use ACAD, as it is the most accurate, user-friendly software to create and maintain our assessor parcel maps. It still remains the industry standard for creating parcel maps and subdivisions, which we receive from engineers and surveyors in digital format.

By: Kim Ballachey, Cadastral Mapping Technician II


STANISLAUS COUNTY

The GIS parcel base is not accurate enough to use for the creation of Assessor maps, even though we created it in the Assessor's office with the help of our county IT department. We did not have any money for the purchase of high-precision aerial photographs as a true base for the parcel layer. Therefore, we are still creating Assessor maps using AutoCAD. It is also easier to hire AutoCAD-proficient mappers than GIS mappers.

By: Cynthia Schmidt, Mapping Supervisor


TULARE COUNTY

We, in the Tulare County Assessor's Cadastral Mapping Unit, are staying put for a while longer.
The Assessor's Cadastral Mapping Unit, composed of 5 Cadastral Mapping Technicians and one Cadastral Supervisor, create and update our 5200 individual detail assessment maps using AutoCAD 14. These 5200 maps in the form of ".DWG" and/or some ".TIF" and/or some ".PDF" files are stored in a "folder" on a computer server only accessible to the Assessor and constitute the official Assessor's maps. Weekly, an updated copy of this folder is made available to the Tulare County Geographic Information System Unit, located four miles away, via our shared computer server.
The GIS Unit, composed of one GIS Technician and one GIS Analyst use this copied folder to weekly insert and "massage" the Assessor's map files into the GIS parcel layer on a "best fit" basis to achieve the "seamless" GIS parcel level layer. The resulting parcel level layer does not constitute the official Assessor's maps. The resulting product is their product.
While the GIS parcel level layer may be accurate enough for broad planning and development purposes, the Assessor here still chooses to use the individual detail assessment maps for local assessment and taxation purposes, since they are the most accurate and to scale and handy for use by appraisers in completing their field work and for making annotations.

By: Ken Swearingen, Cadastral Supervisor


STATE BOARD OF EQUALIZATION

DO YOU HAVE A GIS PARCEL BASE?
18 counties are completed and 5 are in process.
WHO CREATED YOUR GIS ASSESSOR PARCEL LAYER?
We get the parcel base data from the counties.
ARE YOU STILL USING AUTOCAD? IF SO, WHAT ARE THE REASONS?
Yes, due to training issues and availability of prospective employees already trained. We are in the map production business; analysis is secondary. ESRI still can't draw a line worth a damn, but the reality is that we can't do our job without both Autodesk and ESRI.

By: Ralph L. Davis, Research Analyst II (GIS)