PROGRESS REPORT, COMMITTEE ON SURFACE DRAINAGE OF HIGHWAYS

AT THE THIRD ANNUAL MEETING HELD ON DECEMBER 1, 1947, PROGRESS ON RESEARCH PROJECTS WAS REPORTED. THE OHIO DRAINAGE GUIDE, WHICH IS TO BE USED AS A TOOL TO FACILITATE HYDRAULIC DESIGN OF CULVERTS AND SMALL OPEN CHANNELS, WAS DISCUSSED. THE BASIC PRINCIPLE FOLLOWED IS THAT OF DESIGNING CULVERTS AS HYDRAULIC STRUCTURES TO CARRY A DESIGN DISCHARGE ESTIMATED IN CUBIC FEET PER SECOND. CHARTS ENABLE DETERMINATION OF THE DEPTH OF PONDING AT THE ENTRANCE FOR ANY GIVEN DISCHARGE DEPENDING ON THE HEAD LOSS THROUGH THE STRUCTURE MEASURED FROM THE TAILWATER ELEVATION IN THE OUTLET CHANNEL OR, IN THE CASE OF BARRELS ON STEEP GRADES, ON THE SIZE AND SHAPE OF THE ENTRANCE. THE U. S. GEOLOGICAL SURVEY REPORTED ON STATE STUDIES ON STATISTICAL ANALYSES OF STREAM FLOW RECORDS, GAGING STATIONS ON SMALL DRAINAGE AREAS, FLOODS, THUNDERSTORMS, AND DAMAGE SUITS. A DISCUSSION OF RESEARCH ON THE HYDRAULICS OF CULVERTS AND A RESEARCH PROPOSAL ON UNDERSCOUR AT BRIDGE PIERS AND ABUTMENTS IS INCLUDED.