Tradeoffs of Ecosystem Services from

Wetlands in the Houston Region

L. James Lester1, Gregory R. Biddinger1 and Lisa A. Gonzalez1

1Houston Advanced Research Center, The Woodlands, TX, USA

Wetland Services vs. Land Value

Major positive benefits of urban wetlands

◦ Habitat

◦ Nutrient and pollutant assimilation

◦ Stormwater retention

◦ Climate amelioration (heat island effect)

Major issues with urban wetland protection

◦ Loss of land value if undeveloped

◦ Increased cost of development and infrastructure if wetlands protected

◦ Lack of regulatory and nonregulatory frameworks for protection at various levels of government

Growth by Decade in the Houston Region

(Classic Urban Sprawl)

Red = 70’s

Green = 80’s

Yellow = 90’s

Purple = 2000’s

LU/LC Map of Houston 2008

No Data

Developed

Agriculture/Grassland

Forest

Wetland

Bare

Open Water

Legend

Houston-Galveston Area Council

Harris County and Wetlands

Harris County is currently 16.7% floodplain

◦ Reduced by development

◦ Neighboring counties are 21% – 46% floodplain

Texas Coast palustrine wetlands (prairie pothole complexes)

◦ Typical size 0.5 ac – 25 ac

◦ Typical depth 3 in – 16 in

Typical palustrine wetland stores 76% - 93% of annual input

From 1996 – 2005 Harris County lost 4,149.5 acres of

palustrine wetlands to development (0.3% per year)

Functional

Analysis of

Local

Palustrine

Wetland in

2008 - 2009

Prairie Pothole

Wetland

Complexes in

Harris County

Flooding after Tropical Storm Allison

Flood Damage in Harris County

Tropical Storm Allison June 2001 (Extreme)

◦ Precipitation up to 37 inches in 4 days

◦ 30,662 insurance claims (>45,000 homes damaged)

◦ $1,103,765,221 total cost

Flood Damage 1996 – 2007

◦ $1,162,105,186 total

◦ Non-Allison = $58,339,965

High Rainfall is Common

High Monthly Rainfall Amounts

◦ July 2005 = 12.96 inches

◦ October 2006 = 19.26 inches

◦ April 2009 = 15.61 inches

April 18, 2009 flood

◦ 5 deaths

◦ 350 homes flooded

◦ $3.5 million in damages

Wetland Permits and Flooding

(Trading Wetlands for Development)

11,149 Section 404 permits in Texas coastal counties

1991 – 2003

42% affecting palustrine wetlands

◦ Limited protection (2001 and 2006 supreme court

rulings)

Permits in 100 year floodplain in USACE Galveston

District

◦ 1991 – 2003: 32% - 41% annually

Each permit on average increases flood damage by

$212 per flood (urban permits are costliest)

NWF Study of Insured Flood Losses

(Higher Ground 1998)

FEMA Database ‘78 – ‘95 (Claudette 79 and

Alicia 83)

Houston & Harris County had 3,681 properties

with repetitive flood loss

2.9 losses per property over 18 years

$211.5 million paid out (no uninsured losses

included)

Summary

Urban wetlands retain storm water and provide

other services

Urban areas have high demand for land

◦ Undeveloped floodplain land in Harris County is $40K

to $1M per acre

Development in Gulf Coast urban areas creates

high wetland conversion activity

Profit from wetland conversion results in costs

from flood damage

Economic Value of Palustrine Wetlands

Economic cost of wetland conversion is cumulative and

long term

Value is greatest in intensively developed area

Flood avoidance can be improved by protection of

ecosystem services

◦ Land development codes and protected areas have highest

negative correlation to flood damage

Land use decisions currently favor economics of

wetland destruction and structural flood mitigation

Information Gaps

Effect and value of wetland mitigation policy

Ability of low impact development storm

water designs to replace wetland benefits

Thank you for your attention.

Questions?