COMPREHENSIVE FLOODPLAIN MANAGEMENT : Promoting Wise Uses of Floodplains

1. CA Department of Water Resources/ CIFMCG Workshop COMPREHENSIVE FLOODPLAIN MANAGEMENT: Promoting Wise Uses of Floodplains July 2006

2. Comprehensive Floodplain Management Workshop Natural Floodplain Functions, Services and Societal Values

3. Workshop Modules • Comprehensive FPM • NFIP Overview • FPM No Adverse Impact Strategies • Natural Floodplain Functions and Societal Values • Flood Management Economic Analysis • Ecosystem Evaluation Methods • Case Study • Technical and Financial Assistance

4. Natural Floodplain Functions • Floodplain functions includes all the physical, chemical and biological processes that sustain floodplains • Floodplains perform a multitude of complex and interrelated functions which: • Provide biological support • Provide valuable goods and services to society

5. Natural Floodplain Functions • If we can identify “societal” goods and services, then we might be able to develop monetary values • If we can assign monetary values, then we can include them in economic analyses • Including them in economic analyses helps us better evaluate projects that include ecosystem restoration

6. Floodplain Functions, Services and Societal Values • Natural Floodplain Functions • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

7. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

8. Manage Flows • Functions • Transport water, nutrients and organisms • Spread and retain surface and subsurface water • Moderate speed, force, depth and timing of flows • Maintain base flows • Maintain sediment balance • Maintain connectivity between channel and floodplain • Societal values • Protection of life and property • Avoided flood/sediment control infrastructure costs • Value of flow-related goods and services

9. Manage Flows • Examples • USACE estimate of annual wetland flood control benefits for Charles River, MA -- $17 Million/YR or $2,042/wetland acre • Minnesota DNR cost estimate to replace wetlands flood storage in the state -- $300/AF • Washington DNR cost estimate for a replacement storm water retention system equivalent to lost forestlands -- $2.4 Billion • The degradation of one mile of Louisiana coastal dunes ands vegetation could increase hurricane damage by about $64,000

10. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

11. Maintain Water Supplies • Functions • Increase surface water storage • Promote groundwater recharge • Societal Values • Value of goods and services produced with additional water supplies • Avoid water supply infrastructure costs

12. Maintain Water Supplies • Examples • USACE estimate of annual wetland water supply benefits for Charles River, MA – 100,000 gallons/day or • About $17 per day less than local district costs or • About a $6,000 annual savings in water supply costs

13. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

14. Maintain Water Quality • Functions • Filter nutrients and impurities from runoff • Process organic wastes • Moderate water temperature fluctuations • Societal Values • Value of goods and services produced with improved water quality • Avoid water treatment infrastructure costs • Avoid damages to plumbing, fixtures and appliances

15. Maintain Water Quality • Examples • Louisiana tidal wetlands provide $2,500 worth of water treatment benefits per acre/year • Charles River Basin wetlands can replace water treatment capital costs of $85/acre plus $1,475 in maintenance and operation costs • South Carolina wetlands provide a least cost substitute for a water treatment plant costing $5 million • Lake County (CA) estimates that the Middle Creek Ecosystem Restoration Project would remove up to 40% of the phosphorus entering Clear Lake

16. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

17. Maintain Soil Quality • Functions • Detention of particulates, compounds and elements • Societal Values • Value of goods and services produced with improved soil quality • Avoid soil treatment costs • Examples • Seasonal flooding in the Cosumnes River floodplain provides benefits for the 1,000 + acres planted in organic rice and pasture

18. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

19. Maintain Air Quality • Functions • Removal of atmospheric carbon by vegetation (carbon sequestration) • Vegetation humidifies atmosphere and moderates air temperatures • Societal Values • Avoided air pollution treatment costs • Value of improved health and comfort • Improved property values

20. Maintain Air Quality • Examples • National Park Service estimates that the value of pollution removal by trees in Chicago is about $1 million/year • A single rural tree can remove up to 50 lbs of particulates per year • Trees can provide ambient temperature mediation and help reduce heating and cooling costs

21. Floodplain Functions, Services and Societal Values • Manage Flows • Maintain Water Supplies • Maintain Water Quality • Maintain Soil Quality • Maintain Air Quality • Maintain Plant and Animal Habitats

22. Maintain Plant and Animal Habitats • Functions • Maintain characteristic and diverse plant and animal communities • Provide habitat interspersion and connectivity • Provide breeding and feeding grounds • Protect habitat for species of special concern • Maintain ecological succession

23. Maintain Plant and Animal Habitats • Societal Values • Value of goods and services associated with habitats • Improved property values • Enhanced economic development • Preservation values • Avoided habitat enhancement/replacement costs • Recreation

24. Maintain Plant and Animal Habitats • Examples • Urban stream restoration projects increased adjacent residential property values by $4,500 to $19,000 • Riparian/wetlands restoration at new detention basins valued at $8,600 - $50,000/acre based upon regional mitigation bank costs • Riparian/wetlands habitat restoration valued at $3,200/acre based upon foregone commercial development opportunities of similar property sold to a land trust

25. Maintain Plant and Animal Habitats • Examples (Cont’d) • Unit day values for recreational activities (exs: camping, $24; picnicking, $21; biking, $61; boating, $51) • Habitat restoration can stimulate economic development (exs: Napa, San Luis Obispo)

26. To Summarize… • Floodplains perform a multitude of complex and interrelated functions which: • Provide biological support • Provide valuable goods and services to society • Functions include: • Manage flows • Maintain water supplies • Maintain water quality • Maintain soil quality • Maintain air quality • Maintain plant and animal habitats

27. To Summarize… • If we can assign monetary values to floodplain functions and services, we can include them in economic analyses • Including them in economic analyses helps demonstrate benefits for multi-objective projects • More info?? See DWR/EPA study reports at: www.economics.water.ca.gov/documents.cfm

28. What’s Next? • Flood Management Economic Analysis