GIS staff demonstrate county mapping tools; assessors and committee discuss how multipliers affect assessed values
Loading...
Summary
LaSalle County GIS staff demonstrated public and internal mapping tools, aerial imagery and damage-assessment apps. Committee members and the assessor’s office discussed how township multipliers and sales ratio studies affect assessed values shown in the GIS viewer.
Colin (GIS staff) demonstrated LaSalle County’s public and internal GIS tools to the Tax/Zones/GIS Committee on March 18, showing parcel viewers, historical aerial imagery, EagleView oblique photos, and emergency-management applications the county uses for damage assessment and evacuation mapping.
Colin said the public GIS site received about 708 views in the last 24 hours and over 100,000 views in the past year. He demonstrated how the mapper displays current and historical aerial imagery, parcel attributes, and a property-reporting tool that ties assessment and tax details to mapped parcels. He also ran through an internal assessor-facing application that combines property characteristics, valuation fields and oblique images the assessor staff use for review.
Discussion on assessments: Committee members and assessor staff asked how GIS outputs relate to assessed values. Janet (staff from the assessment office) explained that assessed values can change year to year because of township-level multipliers derived from the state’s sales ratio study. She said a property shown at $57,101 in a prior (2023) tax year could be reflected at $63,000 in a later (2024) tax year once the township multiplier is applied to bring assessments toward one-third of market value.
Colin showed a separate emergency-management viewer with sensitive layers (chemical reporting, functional-needs population) and an EMA damage-assessment application used after the Ottawa tornado. The damage-assessment app links field photos directly to parcel points and was used to create reports submitted to the Illinois Emergency Management Agency after the event.
Why it matters: committee members said the public uses the parcel viewer to check their assessments and tax details; county staff emphasized that multipliers and year-to-year adjustments can change the assessed values people see and the best source for explanations is the assessor’s office.
Formal actions: the committee voted to place the Assessors’ report and the GIS report on file; both motions carried by voice vote.
Ending: Colin said county GIS maintains roughly 70,000 parcels, manages ArcGIS Online accounts for 88 county users, and supports departments including EMA, planning and assessment. Committee members requested a repeat demo or follow-up materials for public outreach to explain how assessments and multipliers interact with values shown in the parcel viewer.
