sealing channels to the banks of said body of water and floatable means extending across said body of water and into said channels capable of holding back petroleum products and other floatable debris released upstream into said body of water application_number US 68198176 A description referring to the figures there is shown a device for holding back contaminants which float upon a body of water and more particularly one which has variable levels due for example to the effects of rainy seasons etc in order to perform the invention as best illustrated in fig1 a hole is excavated at 10 into the bank 12 of a brook or river and filled with fieldstone 14 at the builders option cement or cemented fieldstone may be utilized a channel 16 is placed at each side of the stream and abuts the fieldstone such that the channel now seals the water from going around the system of the invention a coated timber 18 is placed across the body of water and is installed such that it floats thereon with a portion below the water level and a portion above the timber gate is constrained by the engagement of the ends thereof with the channels 16 the channel members 16 may be of a conventional u shaped construction or i beam construction as illustrated in fig2 and would be driven into the ground or bed of the stream for a number of feet and would extend above the flood level of said stream the ends of the timber 18 are trimmed as illustrated at 20 in fig2 to fit loosely within a channel 16 of.