HYDRAULIC EFFICIENCY OF HIGHWAY STORMWATER INLETS

This study evaluates the efficiency of stormwater inlets used by the Nebraska Department of Roads (NDOR) and includes a literature review of bicycle safety for inlets. The inlets studied include the "Nebraska Flume" inlet, the slotted vane inlet, and the NDOR standard 72-inch (183-cm) curb opening inlet. The tests on the "Nebraska Flume" inlet included modifications to the design. A full scale model, with the ability to change both the longitudinal and cross slopes, of an 8-foot (2.4-m) shoulder lane was used to conduct the tests. The longitudinal and cross slopes tested were 1%, 3%, and 5% and 2%, 4%, and 6%, respectively. The report describes the hydraulic performance of the "Nebraska Flume" inlet, the slotted vane inlet, and the NDOR standard 72-inch (183-cm) curb opening inlet. The grates tested with the "Nebraska Flume" inlet consisted of open hole, Deeter model 2064, and Nebraska 5-bar. The hydraulic performance of the inlets is presented in terms of inlet efficiency. A series of inlet efficiency curves document the performance of the different inlets at different slope configurations. The study resulted in these conclusions. First, the "Nebraska Flume" inlet performed best with the Nebraska 5-bar grate. Second, the "Nebraska Flume" inlet performed best when modified by moving the outer curb in to the edge of the inlet opening, except for slope combinations of 1% longitudinal slope with cross slopes of 4% or lower. Finally, the slotted vane inlet performed best at the lower cross slopes, while the "Nebraska Flume" and standard 72-inch (183-cm) curb opening inlet performed best at the higher cross slopes. Methods for design were developed to aid in inlet planning. For the "Nebraska Flume" inlet and the slotted vane inlet, the procedure involved the use of design charts. To help in the design of the standard 72-inch (183-cm) curb opening inlet, the procedure involves an efficiency equation.

  • Corporate Authors:

    University of Nebraska, Lincoln

    College of Engineering and Technology
    Lincoln, NE  United States  68503

    Nebraska Department of Roads

    1500 Highway 2, P.O. Box 94759
    Lincoln, NE  United States  68509

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • McCallan, R M
    • Hotchkiss, R H
  • Publication Date: 1996-5

Language

  • English

Media Info

  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 140 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00727215
  • Record Type: Publication
  • Report/Paper Numbers: NE-DOR-R-96-1, Final Report
  • Contract Numbers: SPR-PL-1(31) P483, SPR-PL-1(33) P497
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Oct 4 1996 12:00AM