Interpreting Wetland Areas

Discuss how wetlands can affect

utility and value

Applying Assessing Principles

Understanding Wetlands

Locating and Identifying Wetlands

Discuss how to put it into practice

Wetland Functions

• Prevent Flooding

• Recharge Ground Water Aquifers

• Prevent Shorelines from Erosion

• Preserve Water Quality

• Preserve Critical Habitats

Wetland Definition

• INUNDATED OR SATURATED SO THAT IT SUPPORTS WETLAD VEGETATION ADAPTED FOR WET SOILS

Wetland Identification

1. Hydrology

2. Hydric Soils

3. Hydrophitic Vegetatioin

Wetland Types

• Freshwater Wetlands

• Coastal Wetlands

Coastal Wetland

Inland Marshes

Wet Meadows

Peatlands

Shrub Swamps

Forested Wetlands

Forested Wetlands

Forested Floodplain

Vernal Pools

Vernal Pool in Summer

Significant Vernal Pools

Vernal Pools

Appraisal Process

DISCOVER

VALUE

LIST

DISCOVERY

• Aerial Photos• On Site Inspection• National Wetlands Inventory (NWI)• Google Earth • Tree Growth Reports• Code/Planning Files• Real Estate Listings

National Wetlands Inventory

• OGIS

• NWI

• LOCALIZED COVERAGE

• USE ARCMAP

• USE CAMA

GOOGLE EARTH

• DOWNLOAD GOOGLE EARTH

• PARCEL LINES

• ACCESS THROUGH OGIS

– http://www.maine.gov/megis/catalog/

• SAVE

LIST

• Land Lines

• Backup Documents

LAND LINES

LAND LINES

Value Considerations

• Utility

–Physical limitations

–Legal Restrictions

–“Grandfathering”

• Market Preferences

• Fairness

Excess (Rear) Land

• Does excess land include wetlands?

• Are wetlands listed separately?

– Advantage: can study the market

– Disadvantage: have to have a degree of accuracy

• What are the impacts of listing wetland?

– How much value to put on it?

Baselots

• What are implications of wetlands on a baselot?

• How should we calculate the baselot value?

Discount Calculation (Base Lot)

1 - SQRT (PERCENT GOOD) = DISCOUNT

1 - SQRT (75%)

1 - 87% = 13% , say 10%

Take-aways

• Understand and explain wetlands.

• Mind your parcel line coverage.

• Use the National Wetland Inventory, but use your judgment, too.

• Google Earth is helpful.

• Develop a policy on how to handle wetlands.

• OGIS is spiffy!

• Don’t forget the market.

REFERENCES

Maine Wetlands and Boundaries by Ralph W. TinerState of Maine Department of Economic and Community DevelopmentJune 1994

“Wetlands in Maine“Department of Environmental Regulationhttp://www.maine.gov/dep/water/wetlands/types.html

“National Wetlands Inventory”http://www.fws.gov/wetlands/

“Maine Office of Geographic Information” (OGIS)http://www.maine.gov/megis/

“Google Earth”https://www.google.com/earth/

David SawyerAssessor, Town of Windhamdgsawyer@windhammaine.us