{"data":{"id":"us/23-cfr-650.117","jurisdiction":"us","citation":"23 CFR 650.117","heading":"Content of design studies.","body":"(a) The detail of studies shall be commensurate with the risk associated with the encroachment and with other economic, engineering, social or environmental concerns.\n(b) Studies by highway agencies shall contain:\n(1) The hydrologic and hydraulic data and design computations,\n(2) The analysis required by § 650.115(a), and\n(3) For proposed direct Federal highway actions, the reasons, when applicable, why FEMA criteria (44 CFR 60.3, formerly 24 CFR 1910.3) are demonstrably inappropriate.\n(c) For encroachment locations, project plans shall show:\n(1) The magnitude, approximate probability of exceedance and, at appropriate locations, the water surface elevations associated with the overtopping flood or the flood of § 650.115(a)(1)(ii), and\n(2) The magnitude and water surface elevation of the base flood, if larger than the overtopping flood.","path":["Title 23—Highways","CHAPTER I—FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER G—ENGINEERING AND TRAFFIC OPERATIONS","PART 650—BRIDGES, STRUCTURES, AND HYDRAULICS","Subpart A—Location and Hydraulic Design of Encroachments on Flood Plains"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-23.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:50Z","sha256":"9205e8fe903926dcca328dbbacc7f0653aeb3881d95ab5b7815ccbce214f8f8d","source_id":"us-cfr","stale":true,"prev":"us/23-cfr-650.115","next":"us/23-cfr-650.201"},"notice":"GroundRules: Original legal text. Not legal advice."}