Culvert pipes are commonly used to direct the flow of water beneath roads, for example to accommodate the drainage and dissipation of rainwater. When culvert pipes are blocked by debris, the resulting restriction to the flow of water through the drainage pipe can result in flooding. One particularly problematic source of blockage is the formation of damns by beavers which are well known to construct damns across the open end of culvert pipes to back up water flow and create a pond.
Culverts are also known to be a source of danger to children in that strong currents resulting from the dissipation of rainwater and floodwaters and the like can draw children into a culvert where they can become trapped.
In view of flooding and general safety concerns, various protective devices have been contemplated to limit access to the open ends of culvert pipes which minimizes blockage of the culvert pipe by large debris carried to the culvert pipe by the flow of water. Some examples are disclosed in U.S. Pat. Nos. 7,441,989 by Fleming, 6,447,206 by Fleury, and 5,102,537 by Jones. In each instance, a generally conical screen structure is mounted on the open end of the culvert pipe to restrict access by beavers. Due to the large diameter of many drainage culvert pipes, the resulting size of the conical screen can be very large and cumbersome to transport and deliver to an installation site. Furthermore, known conical screens are typically provided with an annular ring structure at the apex end thereof, but debris can become readily lodged in the open ring structure in some instances. The open ring structure at the apex may also result in children being trapped therein under force of drainage water currents.