Climate Change Issues and Planning for NYC’s Water Supply

1. Climate Change Issues and Planning for NYC’s Water Supply 2008 Watershed Science and Technology Conference Thayer Hotel, West Point NY Lorraine L. Janus, Ph. D. Chief, Water Quality Science & Research NYCDEP Bureau of Water Supply ljanus@dep.nyc.gov

2. Presentation Outline: • Climate change planning for NYC - context • Formation of DEP’s Climate Change Task Force • Climate Change Observations and Predictions • Water Quantity and Water Quality Issues • NYCDEP’s Action Plan • Importance of climate change research as the basis for planning the future • Direction of National Climate Change Research • AwwaRF’s Climate Change Initiative

3. NYC’s Future - PlaNYC Goals: • PlaNYC goal: sustainability in 2030 • Challenges are: pop growth, aging infrastructure, increasing pollution pressure • Must plan: back-up systems for water network, upgrade transit systems, clean reliable power • Environmental goals: • Mitigate climate change – 30% GHG reduction • Cleaner air • Clean-up of contaminated land • Reduce water pollution

4. Genesis of DEP’s Climate Change Task Force • 2001: Metro East Coast Assessment, prepared by scientists at the Columbia Univ. Earth Institute • 2004: Developed agency-wide DEP Climate Change Task Force in collaboration with Columbia University Center for Climate Systems Research and NASA’s Goddard Institute for Space Studies (GISS) • 2006: Draft Guidelines Report and Climate Scenarios Report

5. Climate Change Task Force Mission Statement: Ensure that DEP’s strategic and capital planning take into account the potential risks posed by climate change — sea level rise, higher temperature, increase in extreme events, and changing precipitation patterns —on the City’s water supply, sewer and wastewater treatment systems.

6. Climate Change Science is Required for Planning: Observations and Predictions NASA/GISS developed future climate scenarios for the Northeastern US • Sea level rise • Increasing temperature • USGS has provided analysis of observations in the Catskills • Increases in stream temperatures • Earlier snowmelt

7. Temperature increases in the Northeastern US: Past: 100+ years of measurements Increase of ~ 2.5 F Future: predictions to 2080 Increase of 4 to 7 F

8. Sea Level Rise in the Northeastern US: Past: 85 years of measurements Rise of ~ 12 inches per century Future: predictions to 2080 Increase of ~ 15 inches

9. Projected Change in Days with Heavy Precipitation (>1 inch/24 hours)from the Metro East Coast Report, 2001

10. Projected Change in the Flood Recurrence Interval of the 100-Year Stormfrom the Metro East Coast Report, 2001

11. Why is this important? Changes in temperature affect many components and rates of the hydrological cycle.

12. Hydrologic Water Balance - climate forcings Precipitation Snowpack Air Temperature Melt Relative Coeff Humidity Rain + Direct Runoff Solar Radiation Snowmelt by HRU Latitude Curve Delay Infiltration Elevation Number Coeff Soil Water PET Capacity Unsaturated Recess Zone Season Bypass Coeff Coeff Vegetation Cover Coeff Saturated Zone Baseflow ET Streamflow

13. Climate Change will affect the vast resource of the water supply and its ecology in many ways: • Primarily a surface water supply • 19 reservoirs & 3 controlled lakes • System Capacity: 550 billion gallons (over 2 billion kiloliters) • Serves 9 million people (1/2 of population of New York State) • Delivers approx. 1.2 billion gallons (4.5 million kiloliters) per day to the City • Source of water is a 2,000 square mile (5,180 square kilometer) watershed in parts of 8 upstate counties • Operated and maintained by NYCDEP

14. How will climate change impacts reverberate through the natural system? • How does the hydrological cycle affect ecology and limnology? • Shift of ecological zones, e.g., plant zones • Lake trophic status is determined by the balance between nutrient loads and flushing rates, then light and temperature • What are the ecological repercussions and how will they affect water quality? • Animal habitats will shift with vegetation & temperature • Algal growth and decay rates will determine oxygen depletion, metal and nutrient reflux, taste and odor, DBPs, fish kills, etc.

15. What are the Water Quantity Issues? • Droughts • Floods • Infrastructure capacities: • Dams • WWTPs • Stormwater BMPs • Policies for operations, watershed protection, ecological preservation, etc.

16. Delaware System: Flooding at Downsville due to Hurricane Ivan WWTPs shift to wet weather ops Monitoring of water supply intensified to track problems Equipment moved to high ground

17. What are the Primary Water Quality Issues? • Bacteria and pathogens • Organic precursors to disinfection byproducts and dissolved substances • Eutrophication (increased biological activity) • Turbidity

18. Climate will affect waterfowl migrations - a significant source of coliform bacteria BIRDS: COLIFORMS:

19. Will climate change affect Pathogen abundance? -Giardia varies inversely with temperature - unknown why; will require future research

20. Nutrients lead to algal blooms: • Impacts • Increased rainfall, nutrient loading, and temperature effects: • oxygen depletion • taste, odor and color problems • fish kills • and DBPs Actions • Reduce nutrient loads: installed tertiary treatment at > 100 WWTPs • Develop Watershed Programs: Whole Farm Program to control agricultural sources from ~300 dairy farms • Fine tune chlorination for DBP control • Use low phosphate detergents

21. Turbidity due to intense rainfall and erosion: - may require alum treatment

22. Schoharie reservoir after a major flood event

23. NYCDEP’s Climate Change Activities: 2003 – joined EU CLIME (Climate impacts on lakes) – book to be published soon 2004 – Climate Change Task Force formed 2005 – Bureau-wide review of vulnerabilities 2006 – Assessment and Action Plan drafted – AwwaRF PAC for project to apply Decision Analysis for CC planning (WQD) 2007 – refinement of science on-going; basis of actions 2008 – NYCDEP Climate Change Program: Assessment and Action Plan issued – Integrated Modeling Plan created (WQD) – AwwaRF involvement in Expert Panel to guide national research agenda (WQD) – WUCA member in support of Decision Analysis to guide costly policy and infrastructure decisions (OEPA)

24. NYCDEP’s Climate Change Action Plan • Task 1 – Work with Climate Change Scientists to improve regional climate change projections • Task 2 – Quantify potential Climate Change impacts on NYC Water Systems • Task 3 – Determine and Implement Appropriate Adjustments to NYC’s Water Systems • Task 4 – Inventory and reduce Greenhouse Gas Emissions • Task 5 – Improve Communication and Tracking Mechanisms

25. National Perspective: AwwaRF Climate Change Strategic Initiative – priorities: • Year I. Develop CC resources for water utilities; select content for central knowledge repository website • Year II. Evaluate CC impacts on regulations and opportunities for regulatory change • Vunerability assessment and risk management tools; guidance to select adaptation options • Evaluate impacts of carbon sequestration • Analyze changes in water use under regional CC scenarios • Develop approach to design sustainable water assets

26. What are the benefits of Climate Change Planning (Risk Management) ? • DEP has experienced events that demonstrate system vulnerabilities even under current conditions • Adaptations for climate change improve ability to deal with current climate variability • Proactive planning for climate change can reduce economic, social, environmental, and legal risks • Integrating adaptations into infrastructure maintenance and replacement can be cheaper than playing catch-up or bearing impacts of failure

27. Acknowledgement • Management of NYCDEP: • Commissioner Lloyd, • DC Paul Rush, and • Director Steve Schindler • Staff of NYCDEP Water Quality Directorate • Kerri Alderisio; Don Pierson; Elliot Schneiderman; Chris Nadareski • Climate Change Task Force • Angela Licata; Gary Heath • AwwaRF CC Expert Panel

28. Thank You www.nyc.dep.gov