# Presentation: 515786

## Introducing Web-Based Decision Tools for Environmental 

***Introducing Web-Based Decision Tools for Environmental ***
***Management To Lake Michigan Communities ***
- Bernie Engel

**Long-Term Hydrological Impact Assessment **
**(L-THIA)**

## Land Use Decisions Affect Runoff, Recharge, and Water Quality 

**40%**

**10%**

**50%**

**Natural Cover**

**15%**

**55%**

**30%**

**75-100% Impervious**

**35%**

**30%**

**35%**

**35-50% Impervious**

**Land Use Decisions Affect Runoff, Recharge, and Water Quality **

- Rivers Drying Up

- Stream Ecology Changing

- Water Polluted

- Wells Running Dry

- Wetland Habitat Shrinking

- Stream Banks Eroding

- Rivers Flooding

- Most communities respond to this with a mix of reactive and proactive strategies, including planning

## The most important, large-scale, proactive step:Where you do it can be just as important as what you do

**Planning**

**Multifaceted – so how do you bring environmental concerns into this?**
**Impact Assessment Tools**

## A little history....

*A little history....*

- Northeast Ohio, 1992: “Our wetlands are failing”
- Local Planners: Need model to assess impact of land use change on hydrology.
- Reality:  Available models were data intensive and complex – and getting more so.
- The Aim: To develop a _user-friendly_ model using basic available data for land use and soils, in response to the needs of planners and local environmental groups.

## L-THIA

- Based on the rainfall – land cover – runoff analysis method already used in many communities
- Input:  Land Use Pattern(s) + Soils Pattern
- Process:  Daily Runoff and Pollutant Loading Calculations (30 years)
- Output: Average Annual Runoff and NPS loads for Specific Land Use Patterns

## L-THIA

***L-THIA***

- Originally a simple spreadsheet program
- Now a simple web tool
- GIS extension version also available

## Large-Scale Implementation

- - ICMA (International City/County Management Association)

## Example Applications of L-THIA

- Impacts Assessment for:
- proposed land use change and wetland hydrology.
- residents downstream of a proposed land use change.
- tourism / agriculture transition impacts on a coastal watershed, Barbados.
- past and future land use change in an urban-rural fringe watershed, including impact fee assessment.
- Watershed scale implications of land use change for NPS pollution

## Example: Chagrin River Watershed Partners, Griswold Creek Watershed

**Current**

**Full Build **
**Out**

**Plus Buffers**

**Plus**
**Conservation **
**Design**

## Proposed approaches would reduce but not eliminate the impact

*Proposed approaches would reduce **but not eliminate the impact*

- Current

- + 21%

- + 17%

- + 14%

## So how do you do it?

-  L-THIA Web

**http://www.ecn.purdue.edu/runoff/lthianew**** **

**So how do you do it?**

## Run L-THIA from Text Input form

-  State
-  County

- Land use and hydrologic soil group selection

- Area input

- Click Next

## Tables and charts for interpretation

## What if I don’t have Land Use and Soils Data?

## http://pasture.ecn.purdue.edu/~watergen

- Click Here

- Click Here

- Click Here

*http://pasture.ecn.purdue.edu/~watergen*

## Layer Control

- On/Off

- Map Display

- Display Control
- Zoom in/out
- Pan, Full extent

- Reference Map

- WD Submit Button

## Watershed Delineation: Muskegon County, MI

- Outlet point selected

## Watershed Delineation: Muskegon County, MI

*Watershed Delineation: Muskegon County, MI*

- Run hydrologic models
-  Impervious Area
-  L-THIA
-  SEDSPEC
-  Peak Runoff Estimation

- Results Page

- Result display

## Run L-THIA : Muskegon County, MI

*Run L-THIA : Muskegon County, MI*

- Data Preparation and Run L-THIA

## Run L-THIA : Muskegon County, MI

- Tables and charts for interpretation

## On-line Digitizing Tool:Indian Creek, Tippecanoe County, Indiana

- Land Use Change Using On-line Digitizing Tool and Run L-THIA

- Land Use Change Report after Digitizing

- Land Use Change Using On-line Digitizing Tool

*On-line Digitizing Tool:**Indian Creek, Tippecanoe County, Indiana*

## Run L-THIA : Muskegon County, MI

- But What do the Numbers Mean?

## SEDSPEChttp://pasture.ecn.purdue.edu/~sedspec

## Input for Area, HSG, and Land use

## This is how a culvert design is presented.  The applet provides the user the opportunity to change the number of culverts. Cost and size change accordingly. 

## Buttons allow the user to change dimensions. 

## L-THIA GIS Predicted Results

- Runoff Depth

- Nitrogen Loss

## Important Questions

- (we know they are important because.....)
_**Cost**_:  There is no software or site access cost.  $0, honest!
_**Knowledge / Technical Expertise**_**:**  Basic Version:  Middle school teachers use this with their students.
_**Data**_:  Basic data for IN, IL, OH, MI, and WI is online – you can start with nothing.  You can use your own data and customize the tool.

## Important Questions

_**Staff**_: No commitment for user
_**Platform**_**:**  Basic Version: Internet Access.  You can run a GIS version if you like
_**Validity**_:  Consistent with empirical data and other models.  Accuracy increases with local calibration.

## Important Questions

_**Transparency**_: If you’ve forgotten, it’s explained at the web site
_**Understandability**_**:**  Tool produces average annual runoff and pollutant loadings for each land use decision.
_**Scope**_:  Can be used at site or broad scale, but should be used at the scale of the land use decision.

## How is L-THIA Used?

- Near Columbus, OH – significance of urbanization on runoff and water quality
- Triangle Park, NC – comprehensive land use plan
- NASA KSC, FL – impacts of historical land use change
- Northeast OH – land use planning policy assessment
- Indianapolis, IN – historical impacts
- Kokomo, IN – TMDL development

## Changing Landscapes: 

**Long-Term Hydrological Impact Assessment **
**(L-THIA)**

**Changing Landscapes: **
**Anticipating the effects of **
**local land use decisions.**

**http://www.ecn.purdue.edu/runoff/lthianew**