Tag Archives: gis

The WestCOG Foundation is currently seeking proposals

The WestCOG Foundation, Inc. is seeking qualified Vendor(s) who have expertise with IT, CAMA, and GIS to create effective parcel data for communities without data and to support and manage a Regional GIS CAMA and Parcel View system (Regional GIS) for the Region. This project is the initial phase in a multi-year effort to support regional cooperation and efficiencies. Continue reading The WestCOG Foundation is currently seeking proposals



The WestCOG GIS team is working on a number of initiatives at the moment which are listed below

Project Archives

Regional Viewer

The Regional Viewer showcases WestCOG regional datasets which includes parcel, assessor, transportation, landuse, environmental, and topographical data.

Always Improving. The viewer is continually updated. WestCOG is happy to collect feedback to improve user experience and incorporate desired datasets. Leave feedback through the Viewer’s Dashboard or send directly to Mike Towle at mtowle@westcog.org.

Stay Updated. Updates to the Regional Viewer will be announced via WestCOG’s newsletter. Subscribe today!

Host Locally. Interested communities can link directly to the regional viewer on their websites or even use it as their primary viewer (the latter may provide cost savings).
Regional Viewer Link: https://gis.westcog.org/

Imagery Viewing. 2019, 2018, 2016, 2012, and 1990 imagery available for viewing.

Updated Regularly. Data is scheduled to be updated quarterly. WestCOG will manage data collection campaigns in March (Parcels & CAMA), June (CAMA), September (CAMA), and December (CAMA). Communities interested in more frequent updates can contact Mike Towle for more information.

Abutters Tools. Users can generate a list of abutters in the form of an excel list or mailing labels. The user can select the extent of the abutter ranger or perform an abutter selection based on a geometric shape (manually drawn).

Map Printing. Users can select layers, draw shapes, add points and text to prepare for sharing and printing.

Personalized Viewer. WestCOG can provide Power user access for municipal staff upon request. This would allow individual towns to view sensitive data in a protected space, host municipal specific layers, or other personalized requests. Contact Mike Towle with your requests.

Property Cards. Users can access property cards associated to their properties by: Choosing your town of interest from the drop down menu > Select your parcel of interest within that town > click the “Property Record Card” link found in the left hand ribbon. [This feature is in development and may not work for all towns.]

Training. The viewer has a short tour (opens on start up, and available in the menu) to walk through initial functionality. There is also an extensive Help Manual covering the additional features.

Upcoming Improvements. WestCOG has substantial improvement slated for completion for the end of March which includes.

  • Additional data entries for assessment value data. Currently, mismatched or missing data reads as value 0. Data improvements are tied to WestCOG’s March Data Collection Campaign (A separate email will address this effort).
  • Improved Regional Zoning Symbology.
  • FEMA Flood Zones.
  • Wetland Data.
  • Stormwater Feature Layers
  • Easier access to municipal property cards. Currently users are required to select their community of interest from a drop down menu in order to access property card links
  • Selectable parcels for Stamford.

WestCOG Data Campaigns

Every Quarter (March, June, Sept, December), WestCOG launches Data Campaigns to collect the latest in parcel, CAMA, and planning data from its member municipalities. Collected datasets are then processed and standardized for the extent of the region and made publicly available (with exceptions to sensitive datasets). Contact Mike Towle at mtowle@westcog.org with questions.

March – April Data Campaign:

CAMA Data Tracker
WestCOG Data Schema

  1. March 4th. WestCOG Kicks Off the Data Campaign.
  2. March 4th – April 10th. Assessors develop specialized reports for Data Extracts based on WestCOG CAMA Data Schema.
  3. March 20th. Assessors and/or GIS staff provide most current Data Extract and Parcel data for their respective community.
  4. March 4th – April 17th WestCOG reviews provided data as it arrives. WestCOG may request data keys for unidentified data fields.
  5. April 17th. WestCOG aims to have collected Parcel and CAMA data from all participating communities.
  6. WestCOG will continue to work with communities to collect Parcel and CAMA data.

Fun Fact! The data collected thus far is already being used for interesting applications such as WestCOG’s Regional Viewer and assisting First Responders through CT’s Eagle-1 Program. The latter is overlaying parcel and address information on their night vision imagery systems, very cool!

Parcel & CAMA Data Acquisition

State mandate, PA-1875, requires communities to provide their respective COG with their latest Parcel and CAMA data by May 1st, 2019 and then annually thereafter. WestCOG coordinates this collection with its member communities.

Parcel Data Request: WestCOG is looking for the latest Parcel Data Set usable in a GIS

  • A date for when it was last updated.
  • A unique parcel ID attribute to link with the CAMA data.

If you have a third-party vendor and you provide a contact, WestCOG would be happy to collect the updated data on your behalf from the vendor.

If your community does not maintain a GIS Parcel Data set. WestCOG will defer to its oldest parcel data set

CAMA Data Request: WestCOG is looking for the most detailed CAMA extract it can recieve while maintaining a flat excel format. Many communities have used the extracts made for the Warren Reports. In the mean time, WestCOG is working with the state and CAMA vendors to have them develop a standardized CAMA report that communities can readily provide.

Regional GIS Initiative

Initial Grant Award

In 2012, WestCOG’s predecessor, SWRPA, received Regional Performance Incentive Program (RPIP) funds to develop a regional GIS program to develop a regional GIS Program which would host extensive data resources such as imagery, lidar, contours, and planimetric data. With consolidation of the State’s planning regions, the project was extended to the entire Western Connecticut Planning Region, and was expanded to cover additional tasks (in the areas of property assessment and records).

GIS Data Acquisition

Flight Data for Southern Towns: The project launched in 2014 when the vendor, Kucera, was selected to generate:

  • High resolution imagery (3”)
  • Oblique Imagery
  • Lidar, Elevation Data
  • Planimetrics

This data collected was known as the 2014 Kucera Flight Data.

Flight Data for Northern Towns: RPIP funds were utilized to develop planimetrics data for the 10 northern towns in the WestCOG Planning Region. This effort was performed in 2016 using data from a state flyover performed in 2016.

Planimetrics Update for Developing Areas: In areas with high development activity (Stamford, Norwalk, and along Route 1), remaining grant funds were used to update planimetrics data to match 2016 state flight data. This work was completed by Sanborn in 2018.

Axiomatic Reports

Axiomatic, in partnership with WestCOG and its members, conducted a study of opportunities for regional cooperation in property assessment and records, including the viability of a regionalized Real Property Computer Assisted Mass Appraisal (CAMA) system.

Regional CAMA Study: The study found that the cost savings of a Regional CAMA Service were negligible due to the diversity in property tax base, software, and schedules within the Region. The report did identify four workflow efficiency projects:

  • Regional GIS Parcel-CAMA web viewer
  • Personal Property E-File
  • Automated Deed Integration
  • E-File for Exemptions

This report is explained in detail in the Existing Conditions & Initial Recommendations Report.

Two follow-up reports were developed to facilitate implementation of these projects:

Regional GIS Parcel-CAMA Study: This service would develop a sustainable approach to collect and standardize parcel and CAMA data across the Region, and to share these data via the web. The report provides a breakdown of cost benefits, best practices, and an implementation strategy.

Following this report, WestCOG has performed a Request for Information (RFI). Following the RFI, WestCOG Foundation Inc. is now in the middle of a Request for Proposals (RFP) to identify vendors to provide this service. This project is expected to commence in 2019.

This project is explained in detail in the Regional GIS Web Application Recommendations Report.

Regional Recommendations Study: This report outlines the cost, benefits, and steps for implementation for three projects:

  • Personal Property E-File (Completed)
  • Automated Deed Integration (In Progress)
  • E-File for Exemptions (Pending)

These projects are explained in detail within the Regional Recommendation Prioritization Report.

2020 Census Boundary Update

The US 2020 Census’ Participant Statistical Areas Program (PSAP)is completed and won’t return until 2029. Every ten years, the Census reviews its existing boundaries. These boundaries serve as the foundation for tabulating statistics on socioeconomic data. The Census has designated WestCOG as the Primary Official (PPO) to oversee Census Boundary Updates for Fairfield County. WestCOG with member communities, neighboring COGs, and CTDOT to perform these updates. WestCOG updated Census Designated Places (CDP) along with census block-groups and tract boundaries. These updates reduce anomalies and allow for a cleaner reflection of the region.

Census Boundary Update Presentation

Project Archive

Project Archives

Ladders of Opportunity

This federally-funded project involved utilizing Census data to determine the relationship between under-served populations and the accessibility of transportation. This overview provides an introduction to the project.

Electric Vehicles Report

This report evaluates passenger vehicle data from the CT DMV to determine the progress of Electric Vehicle (EV) adoption in the WestCOG and spatial relationship between EVs and charging station.

An Analysis of Connecticut Property Appraisal Accuracy

Using data from the Municipal Fiscal Indicators gathered by the Connecticut Office of Policy and Management, this report provides an analysis of property appraisal accuracy in Connecticut by comparing the sales price of properties sold between 2011 and 2014 with their appraised value (report, annex).

Trends in Connecticut Municipal Finance

Using data from the Municipal Fiscal Indicators gathered by the Connecticut Office of Policy and Management, this report tracks local government revenues and tax rates through the years.

Variances in Connecticut Municipal Revenues

Using data from the Municipal Fiscal Indicators collected by the Connecticut Office of Policy and Management (see report titled “Trends in Connecticut Municipal Finance” above), this report investigates unexpected changes in municipal revenues from state transfers.


Regional Map Viewer

WestCOG’s Regional Map Viewer is a web based platform to view parcel and assessor data within the region. The viewer also showcases a variety of themed datasets such as zoning, geology, contours, and storm water features.

WestCOG’s Regional Map Viewer allows user to review parcels, identify abutters, and print maps.

Bridgewater Bike Map



The Analytics Department at WestCOG provides technical data services for the 18 municipalities in the Region. Services may include Mapping, Modeling, Reporting, and Data Visualization within the sectors of transportation, policy, and urban planning.

Contact Mike Towle at mtowle@westcog.org to set up a consultation for your municipal data or mapping needs.

Regional Viewer

Review local data, Print Maps, Inventory Abutters on the Regional Viewer
Public data available on our Data Downloads Web Page.

Associated Organizations




The GIS and Analytics Group at WestCOG is technically skilled with diverse expertise in a variety of domain areas and data types (e.g. environmental, transportation, and land-use). In addition to GIS skills and software, we have  expertise in data processing, geoprocessing, scripting, image processing, and other analytic areas. Contact Michael Towle at mtowle@westcog.org for more information.


The GIS and Analytics Group at WestCOG can help you conduct your data analyses and mapping visualization using a wide variety of analytic tool, methodologies, and approaches. Our staff has backgrounds in fields like GIS, remote sensing, economics, landscape architecture, geology, natural resources, and environmental science, land-use, and transportation. Call us with your questions.

GIS Training

Municipal Specific Analyses
You might have something specific you want to be able to perform in house. Contact WestCOG to setting up a training.

GIS Basics for Municipal Staff
WestCOG staff can come to your work place, and provide introductory training on ArcGIS Pro, ArcGIS Desktop, and open source software like QGIS

Data Collection
Learn to use Arc Collector (Free with you Arc Subscription) to collect data in the field with your phone.

From Excel to GIS and Back Again
How to get your excel data into GIS, join it with shapefiles, and how to bring it back to excel.

UConn Geospatial Training Program

GIS Groups and Associations


WestCOG Data

GIS Data Hub

Explore WestCOG GIS data online using our Hub Site. The Hub provides access to maps, applications and gis data all within an easy to navigate interface. Casual viewers can now explore our hosted visually.

For those GIS pro users with the necessary software and a need for fast and large downloads, continue exploring our data page.

Administrative Areas

Town, regional, congressional, and school district boundaries.


WestCOG shares a basemap with all its planimetrics and contour data in tile format which can be viewed online or loaded directly into your GIS by adding data through a URL, reference URL below:


Building foot print polygon data for all towns in WestCOG


Census designated regions include block, block group, and tract shapes for our region.


20, 10, 5, 2, and 1 ft contours for the WestCOG region. Data derived from 2014 Lidar Data.

TAZ Projections

TAZ demographic population projections are currently available. These were created for the NYC Metro Area.


Trees, soils, and riparian data


Streams rivers and lakes

Landcover Rasters

DEM, SEM, impervious cover rasters

Land Use Planning

Parcels, Zoning and open space data collected where available from communities


Culverts and impervious cover totals by town, watershed, catchment areas and parcels.


Pavement polygons, road center lines, and street features.


Rail and bus data

WestCOG 2014 Orthoimagery

WestCOG owns a 2014 Leaf off flight data with 3″ resolution and 4-bands and can be acquired upon special request. The latest orthoimagery can be obtained on CT Eco.


Digital Elevation Model (DEM), shows elevation of the surface only and does not represent features such as trees or buildings. Surface Elevation Model (SEM) depicts features as well, including buildings and trees.

Raw Lidar

A large data set not available for download. If needed, please contact WestCOG directly to establish a form of data delivery.

CT Data Resources

Town Data Profiles

Two page summaries with key data for each municipality in CT and regularly updated by the CT Data Collaborative and Advance CT.


Connecticut Environmental Conditions Online (CT ECO) shares imagery and environmental information with the general public through map services.


The primary data source of environmental and natural resource data from the State of Connecticut Department of Energy and Environmental Protection. Home to some unique data sets.


A source of geographic information and Census data and is affiliated with the University of Connecticut library system.

CT Open Data Portal

The data clearinghouse for the State of Connecticut. A source for municipal and state demographics and government oriented data sets (e.g. public safety).

CT Data Collaborative

Striving for informed decision-making across Connecticut. CT Data Collaborative empowers an ecosystem of data users by democratizing access to public data and building data literacy.

Additional Data

Analytic Software

Data Science

Regional Data Science Services

WestCOG provides a suite of data services from data collections to GIS mapping.

Municipal Mapping Services

WestCOG provides limited GIS services for individual member communities. Opportunities can , and extensive services for regional efforts. Limited municipal services include:

  • Technical Support to figure out mapping needs. Unlimited access based on staff availability.
  • Up to three basic maps (displaying and visualizing data). With 1 round of edit requests for each map.
  • A single basic GIS analysis, with a single round of edits. Basic analysis includes up to three forms of analytical tools applied.
  • Project scopes can be greatly expanded if the effort includes more than one community and with support from respective elected officials.

Regional Data Collection

Each April WestCOG pushes out its annual Data Collection Campaign to collect the latest municipal datasets and to ensure that existing data is up to date and authoritative. This data is processed, standardized, and redistributed at a regional scale and for public consumption through our data distributions page or map viewer. Currently WestCOG collects the following data.

Parcel Data. Property boundaries and polygon data. Collected under state mandate.

CAMA Data. Property information (lot size, # buildings, etc.) developed by assessors. Collected under state mandate.

Zoning Data. An inventory of zoning codes displayed geographically.

Open Space Data. Collection of undeveloped properties and their protection status (including unprotected).

Fee Schedule. Includes all known fees by municipality. Developed this year, still under construction.

Regional Map Viewer

WestCOG’s Regional Map Viewer is a web based platform to view parcel and assessor data within the region providing a host of benefits.

Easy Access: A single resource for users to view multiple communities worth of parcel data across town boundaries.

Abutter Tools. Allows identification of abutting properties based on a number of tools. Selected properties can be used develop mailing lists.

Market of Options: Communities can utilize the regional viewer without having to fund their own hosting service.