flood plain information south creek, north creek, catfish - Sarasota ...

away and carried downstream to collect on bridges and otherobstructions to flow. As floodflow increases, masses of debrisbreak loose and a wall of water and debris surc)e~; cownstreamunti I another obstruction is encountered. Debris may collectagainst a bridge unti I the load exceeds its structural capacityand the bridge is destroyed. The I imited capacity of obstructivebridges or CUlverts, debris plugs at the culvert mouth ora combination of these factors retard floodflows and result inflooding upstream, erosion around the culvert entrance and bridgeapproach embankments and possible damage to the overlying roadbed.In general, obstructions restrict floodflows and resultin overbank flows and unpredictable areas of flooding, destructionof or damage to bridges and culverts and, an increased velocityof f low i mmed iate Iy downstream. It is i mposs i b Ie to pred ict thedegree or location of the accumUlation of debris; therefore, forthe purpose of this report, it was necessary to assume that therewould be no accumulation of debris to clog any of the bridge orculvert openings in the development of the flood profi les. SouthCreek, North Creek, Catfish Creek, Clower Creek, Ell igraw Bayou,and Matheny Creek are spanned 28 times by bridges and culverts.Pertinent information on U. S. Highway 41 bridges and culvertscan be found in table 5 on page 24. Some of these structuresare obstructive to floodflows.Flood damage reduction measures - There are no floodcontrol works completed or planned by the Corps of Engineers inthe stUdy area. It is possible that certain works described inthe report titled "Work Plan for Sarasota West Coast Watershed"prepared by the Sarasota Soi I Conservation District for the6--_.-