A Study of Runoff from Small Drainage Areas and the Openings in Attendant Drainage Structures

In 1926, John T. Lynch read to the Kentucky Academy of Sciences a paper entitled, The Relation Between Drainage Area and Waterway Required for Culverts and Small Bridges in Kentucky. The paper was based on a study of many small drainage structures then existing in the highway system, and a general evaluation of the performance of the structures in relation to rainfall and runoff from contributing watersheds. As a result of this report, and in accordance with the suggestions contained in it, the Department of Highways adopted a system of runoff coefficients applicable to different sections of the state and usable in the empirical Talbot formula for computing the quantity of flow from a drainage area. This information was contained in the booklet of instructions for bridge and culvert surveys which has been in effect for almost 25 years