How is an elevation reference mark identified on a Flood Insurance Rate Map (FIRM)?

An elevation reference mark is identified on a Flood Insurance Rate Map (FIRM) by a small "x" along with the notation "ERM" or "RM." This notation indicates to users where they can find established references for measuring elevations, which are crucial for understanding flood risks and requirements in relation to the National Flood Insurance Program (NFIP). Elevation reference marks are particularly important for floodplain management as they help in determining the Base Flood Elevation (BFE), ensuring compliance with regulations, and assisting property owners in making informed decisions regarding flood insurance and potential mitigation measures.

The presence of "ERM" or "RM" signifies that these marks can aid in determining the elevation of structures in relation to the floodplain, ultimately supporting safer community planning and zoning. The other symbols like the star, dot, or triangle are not used for this purpose and would not provide the necessary information regarding elevation references. Understanding the correct identification of these markers is essential for professionals involved in floodplain management and for property owners navigating flood insurance requirements.