Feedback on the New Datums

1. Feedback on the New Datums Federal Emergency Management Agency Risk MAP Paul Rooney 2015 Geospatial Summit April 13 to 14, 2015

2. Preparation • Our major products/services which will be affected by the new datums: • National Flood Insurance Program (NFIP) Flood Maps • NFIP insures about $1.3 Trillion in property • To be eligible communities must agree to minimum building standards in high risk areas • Property owners in high risk areas must purchase insurance to be eligible for various federal program and most conventional mortgages. • To implement these requirements FEMA publishes flood maps that define: • The boundaries of the high risk area • The elevations that buildings must be built in the high risk area • Flood risk analysis and mapping depends on good data, particularly accurate elevations. • Our preparations to date include: • Minimal – most transition will need to occur after datums are available • Currently working on transition from NAD83(1986) to NAD83 (2011). May provide template for future.

3. Advantages / Challenges • We are excited because...Implementation of NFIP requires thousands of precise horizontal and vertical measurements of buildings • Communities must adopt the FEMA flood hazard into their land use and building codes • Communities attach a copy of the map to their ordinance as the official record • Permitting of new construction, real estate transactions, and flood insurance all need determination of flood risk status and minimum building elevation – where applicable • Horizontal locations of high risk boundaries and minimum building elevations are referenced to the NSRS to facilitate these determinations • Administratively, very small differences can have a large impact • We are concerned because...Changing the datum on maps requires administrative actions by communities • Once the boundaries and elevations are published by FEMA they are fixed administratively and enforced by Federal, state and local laws • Maps can be updated by individual or communities submitting better technical data • FEMA can revise the analyses and publish new maps • Communities and affected property owners have the opportunity to review changes • A large map revision will typically take 3-5 years and can sometimes take much longer.

4. Transition Tools / Outreach Needs • The tools, products, or services we need most (from NGS or others) are: • The ability to convert between datums (and datum realizations) • The National Flood Hazard Layer is a large (several gigabyte) GIS dataset of 20+ layers covering CONUS, AK, HI, PR, CNMI, Guam • The NFHL is currently in NAD 83 (1986) • ESRI currently has transformations only through HARN • Geocon/Geocon11 grid transformation will be added later this year. • Challenges • HARN grid overlap, including states with multiple grids. • No HARN for Alaska – handling with uniform shifts OK? • The outreach we need most (from NGS or others): • Outreach is difficult because the issues are so complex • Most NFIP end users will not understand and training and outreach is not likely to be solution