1. Overview Presentation for FMA 2007 NATOMAS INTERIOR LEVEE PROTECTION PLAN (NILPP)

3. Natomas Interior Levee Protection Plan 1.Interior Compartmentalization Levees + 200-year flood protection system. 2.Additive protection to the Natomas Levee Improvement Program (NLIP-SAFCA) 3.Residual Risk Protection: A failure in the regional (SAFCA) levees at one compartment would result in flood damages being isolated within a single compartment. 4.In-basin protected “safe zone” from which rescue and recovery efforts could be mobilized. The Natomas Joint Vision Planning Area, Metro Airpark, and the Airport would be encircled by interior levees. 5.Proposed Facilities would be constructed to maintain the function of Existing Basin Infrastructure. For example, the levees would cross the RD-1000 canals at several locations requiring that flood gates be used so that the RD-1000 system can function normally, but the gates could be closed in order to isolate damages to a single compartment in the event of a regional system failure.

4. Natomas Interior Levee Protection Plan Defining the Residual Risks (Single Hull System) 1.Following SAFCA NLIP Improvements, FEMA would characterize the single year probability at 0.5% (200-year). 2.Changes to Levee Certification Standards: for example Memorandum’s 34 and 43, Corps of Engineers Risk Based analysis, and Incorporation of New Criteria like Seismic Stability, Vegetation Setbacks, Climate Shift, or requirements to achieve a higher design event recurrence interval. 3.Changes in Laws: for example AB5, “Plans of Flood Protection” 4.Others risks such as the long term effects of deep seepage and subsidence. 5.The Unknown? 6.Decision Making Process.

5. NATOMAS 101 (EXTRA CREDIT) Stats 16 miles tall 8 miles wide 57,000 acres ~ 89 sq miles. NEARLY completely encircled by Levees Water on nearly every border, year round Boundaries: Sacramento River American River Natomas Cross Canal NEMDC – Steelhead Creek

6. NATOMAS 101 (EXTRA CREDIT) Two Local Agencies Completely Cover the Basin Territory: SAFCA RD-1000 Other Agencies: Sutter County Sacramento County City of Sacramento

7. NATOMAS 101 (EXTRA CREDIT) Key Contents: Two Interstates, which intersect within the Basin. (I-5, I-80) Joint State Highway 70/99 Major Regional International Airport Tom’s House Habitat Lands Agricultural Lands ~ 28,000 structures ~ Population in excess of 60,000 to 77,217. ARCO Arena (for now)

8. NATOMAS 101 (EXTRA CREDIT) EXISTING DISTRIBUTION OF STRUCTURES BY ELEVATION BASE FLOOD ELEVATION = 33

9. Natomas Levee Improvement Program (NLIP) Planned Improvements (by SAFCA) “IN SAFCA WE TRUST” SAFCA Assessment increases passed with more than 80% approval TimingDes. Event Protect Single Year Failure Probability Now66-year0.0152 Phase I140-year0.0074 Ultimate w/fed. funds 200-year0.005

10. Natomas Levee Improvement Program (NLIP) Planned Improvements (by SAFCA) SAFCA Also Proposes a Development Fee to Fund improvements to mitigate added potential $ risk POSSIBLE PHASE IN OF FEE FEE WILL ADJUST EVERY 5- YEARS NATOMAS 101 (EXTRA CREDIT) SAFCA DEVELOPMENT FEE Based on Risk of Structural and Content Damage: Replacement Cost of Damages as a percent of Structure Only Value: Depth of Flood ResidentialCommercialIndustrial 0’ – 5’33%72%74% 5’ – 10’70%105%125% 10’ – 15’79%136%146% FEE POSSIBLE JAN. 2008 (AB1600 TYPE) Development Permit Type Proposed Fee $/SF for 1 st 2-floors Intended to Raise total $’s SFR-Single Family2.48$260,000,000 SFR – Two Story2.23 MFR–Multi-Family2.00 Commercial5.14$340,000,000 Industrial3.01 SAFCA stated exemptions would be possible for structures which are raised out of the floodplain, and/or protected by compartmentalization

11. Natomas Basin Interior Floodplain Post ’90’s Levee Improvements, and Pre-RD- 1000 System Upgrades

12. Natomas Basin EXISTING: Airport Panhandle Existing Dev. ConditionCurrent No of Structures At Risk from External Levee Breach 28,000 Ave. Single Event Est. Damages $5.3 B Average Annualized Risk $70M/Year

13. Eastern Quadrant of Natomas Joint Vision Planning Area Shows plan for mitigating Internal Flood Plain Impacts and Development Flows (200-year)

14. NILPP 200-Year Flood Protection Plan NORTHERN SUPER LEVEE LAKE SECTION

15. Natomas Basin Development Projects (NILPP Overlay) East Quadrant (NNJVA) Central Quadrant (NNJVA) Metro Airpark County Separator – Open Space Measure M Airport Panhandle Existing Dev.

16. Natomas Basin Potential Future Elevation Distribution of Structures. BASE FLOOD ELEVATION = 33

17. Natomas Basin Development Projects: Flood Risk Factors of Added Development: ConditionCurrentBuild-out No NILPP Build-out With NILPP No of Structures At Risk from External Levee Breach 28,000107,00052,000 (Single – Event 28,000 & 24,000) Ave. Single Event Est. Damages $5.3 B$24.3 B$4.4 B Average Annualized Risk $/Year $70M* $165M to $331M * $76.2M to $152M * Depends on Final Level of Improvements Implemented by SAFCA NLIP (between 100-year and 200-year assumed). Does not include Dev. Fee SAFCA Improvements. Est. database.

18. Reduces Residual Risk by: 1.Reduces Flood Risk to all people, structures, and infrastructure within the Natomas Basin. At buildout could include as many as 107,000 structures, a population of 250,000 and the supporting infrastructure. 2.Protects the Natomas Joint Vision Area and Airport from an Exterior Levee Breach + Adds protection for the existing development areas and highways. 3.The plan could be expanded to protect the proposed Sutter County development 4.Plan Levees can Maintain Certification: Interior levees are less susceptible to damage from erosion and seepage 5.In the event of a Breach, flood damages are isolated to a single compartment, and infrastructure would remain operational in the protected areas.

19. NILPP IMPACTS - Natomas Evacuation Plan and Hypothetical Flood Depths PRE-PROJECT (BEFORE)

20. NILPP TOPOGRAPHY

21. NILPP HEC-RAS MODEL

22. NILPP SINGLE EVENT IMPACTS BREACH 3 LOCATION- “TIME TO FILL” Fill to Elevation (ft) PlanTime to Fill (hr) 5-10Existing0-3.25 Phase I0-3.25 Ultimate0-3.25 10-15Existing3.25-10 Phase I3.25-10 Ultimate3.25-10 15-20Existing10-66 Phase I10-49 Ultimate10-45 20-25Existing66-116 Phase I49-106 Ultimate45-82 25-30Existing116-260 Phase I106-162 Ultimate82-121

23. PRE-NILPP 0 Mi of CANAL 0 PUMP STATIONS 624 STRUCTURES 964 STRUCTURES 105,246 STRUCTURES 106,210 PARCELS 56,894 ACRES LEGEND RD-1000 PROTECTED PROTECTED FLOODED 1-3’ FLOOD>3 FEET FLOOD>1 FEET AREA FLOODED (Ultimate Buildout Conditions Represented) POST-NILPP 21.5 Mi of CANAL 4 PUMP STATIONS 80,086 STRUCTURES 3,116 STRUCTURES 23,632 STRUCTURES 26,748 PARCELS 21,844 ACRES BREACH 1 - NORTH

24. PRE-NILPP 0 Mi of CANAL 0 PUMP STATIONS 1,679 STRUCTURES 1,084 STRUCTURES 104,071 STRUCTURES 105,155 PARCELS 56,626 ACRES POST-NILPP 29 Mi of CANAL 6 PUMP STATIONS 106,524 STRUCTURES 278 STRUCTURES 32 STRUCTURES 310 PARCELS 5,057 ACRES BREACH 2 - WEST LEGEND RD-1000 PROTECTED PROTECTED FLOODED 1-3’ FLOOD>3 FEET FLOOD>1 FEET AREA FLOODED (Ultimate Buildout Conditions Represented)

25. PRE-NILPP 0 Mi of CANAL 0 PUMP STATIONS 3,070 STRUCTURES 3,221 STRUCTURES 100,543 STRUCTURES 103,764 PARCELS 56,031 ACRES POST-NILPP 16 Mi of CANAL 3 PUMP STATIONS 76,379 STRUCTURES 714 STRUCTURES 29,741 STRUCTURES 30,455 PARCELS 20,815 ACRES BREACH 4 – SOUTH/AMERICAN RIVER LEGEND RD-1000 PROTECTED PROTECTED FLOODED 1-3’ FLOOD>3 FEET FLOOD>1 FEET AREA FLOODED (Ultimate Buildout Conditions Represented)

26. Potential Private Financing of NILPP Improvements CFD financing study demonstrates that the Natomas Joint Vision Planning area CAN fund: Full Fair Share Participation in SAFCA Assessment Possible Participation in SAFCA Development Fee Funding of Interior Levee Improvements Funding of Lake and Flood Storage Facilities Funding of Special Structures such as valves, gate structures, freeway crossings, and additional water storage. Funding of Additional Maintenance $’s to RD-1000 for severance issues – and possible NILPP Maintenance.

27. Financing NILPP Improvements COSTS SUMMARY East Quadrant Plan A (Brookfield + Others)$ 81,000,000 North Interceptor Levee Remainder$ 49,000,000 South and West Interceptor Levees$104,000,000 TOTAL PROJECT COSTS RANGE: $226 M to $234M MINIMUM COSTS FOR NORTH INTERCEPTOR: $111M CFD FUNDING BY NNJVA =~ $5,500 / LOT (Present Val) (Assumes R/W dedication throughout)

28. NILPP and 200-Year Flood Protection Plan What’s Needed to Implement the NILPP? Public & Private Cooperation/Partnership Streamlined Processing of Private & Public Permits Community Support Strong Leadership Funding by Development Right of Way – Dedicated by Land Ownership

29. END OF NILPPPRESENTATION QUESTIONS?