Online Land Use Decision Making Tool

The Long-Term Hydrologic Impact Assessment model is an online tool to assess the water quality impacts of land use change.

1 minute read

June 2, 2003, 4:00 AM PDT

By Chris Steins @planetizen


As local land use decisionmakers, municipal and county leaders regularlymeasure the benefits and costs of development proposals. In addition tofactors such as the extension of existing infrastructure and thedelivery of government services, local officials are beginning toconsider the impact that land use changes will have on a community'swater quality. The Long-Term Hydrologic Impact Assessment (L-THIA) modelwas developed as an accessible online tool to assess the water qualityimpacts of land use change. Based on community-specific climate data,L-THIA estimates changes in recharge, runoff, and nonpoint sourcepollution resulting from past or proposed development. L-THIA's resultscan be used to generate community awareness of potential long-termproblems and to support planning aimed at minimizing disturbance ofcritical areas.

Thanks to Campaign for Sensible Growth

Sunday, June 1, 2003 in International City/County Management Association

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Use Code 25for25 at checkout for 25% off an annual plan!

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

May 7, 2025 - Diana Ionescu

Close-up on Canadian flag with Canada Parliament building blurred in background.

Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?

As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?

April 28, 2025 - Benjamin Schneider

Person in yellow safety suit and white helmet kneels to examine water samples outdoors on a lake shore.

USGS Water Science Centers Targeted for Closure

If their work is suspended, states could lose a valuable resource for monitoring, understanding, and managing water resources.

May 1, 2025 - Inside Climate News

Bike Commute

The Rippling Effects of Bike-to-Work Subsidies

A European movement to incentivize people to commute by bicycle is changing travel patterns and making mobility more sustainable.

May 7 - Momentum Magazine

Senior couple driving car.

Preparing Transportation Systems for the ‘Silver Tsunami’

More Americans than ever will age beyond their safe ability to drive. How will they meet their mobility needs in a car-centric society?

May 7 - Streetsblog USA

Front of Walmart store with sign.

Walmart Announces Nationwide EV Charging Network

The company plans to install electric car chargers at most of its stores by 2030.

May 7 - Inc.

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.

Comprehensive Bikeway Design Workshop

Transportation Research & Education Center (TREC) at Portland State University

Early Bird Deadline – save on your tuition fee!🚨

Institute for Housing and Urban Development Studies (IHS)