Wailuku Riverfront Park - Laserfiche WebLink

Home

In The base flood elevation, 15 and 16 feet at the proposed site, is the estimated elevation of the- 100 -year flood based on the National Geodetic Vertical Datum of 1929 (NGVD). Mauka of the Keawe -Puueo Bridge, the site (except immediately adjacent to the river itself, where no modification or activities are planned) is designated Zone X, defined as areas outside the 500 year floodplain. There are no known flooding problems on this part of the site. Executive Order 11988 requires federal agencies to take action to minimize occupancy and modification of floodplains, and to consider alternatives to avoid adverse effects and incompatible development in a floodplain. If no practicable alternatives exist, the project must be designed to minimize potential harm to or within the floodplain and a notice must be publicly circulated explaining the project and reasons for the project being sited in the floodplain. Furthermore, construction must be consistent with the standards, criteria and intent of the National Flood Insurance Program (NFIP) and its implementing regulations (44 CFR 59 -77). As part of implementation of this Executive Order, HUD requires an "Eight -Step Floodplain Management Analysis" to ensure that all practicable alternatives have been analyzed, that the natural and beneficial uses of floodplains are not adversely affected, that any potential harm to the floodplain or human health and safety can be mitigated, and that the public has had a chance to review and comment upon the proposed project. Chapter 27 of the Hawaii County Code stipulates that any new construction or substantial improvements within Special Flood Hazard Areas must adhere to certain requirements. These may include elevating structures on pilings so that floors are above base flood elevations or anchoring foundations to resist flotation, collapse, or lateral movement. Impacts and Mitigation Measures Most of the improvements contemplated for the park (walkways, picnic tables, etc.) are not substantial structures and would have no effect on the floodplain. Other structures that may be built (e.g., fishing /viewing platforms) would be considered regulated "structures" under the NFIP. These structures would be built to conform with standards regarding foundations, pilings, walls, etc. Because the flooding is coastal in nature, siting any structures in the 100 -year floodplain would have negligible impact on the base flood elevation and the size of the floodplain. An Eight -Step Floodplain Management Decision Making Process analysis of the project was performed by the Hawaii County Office of Housing and Community Development and is contained in Appendix 3. The public notice announcing the opening of the comment period for the process was published in the Hawaii Tribune Herald and is included in Appendix 3. The analysis concluded that implementation of the project would not expose any person to unreasonable risk nor would it adversely affect any natural and beneficial uses of the floodplain. 7