OWP will be closed from 4:00 pm on Friday, December 20, 2024, until 8:00 am on Thursday, January 2, 2025, for Winter Break.
(All times are PST.)
For students in Canada: Due to the ongoing Canada Post strike, please use UPS or FedEx to return your scantrons for grading. You may take your exams online even if you received paper exams.
If exams are submitted: |
Course certificates will be mailed: |
By December 13th |
By December 20th |
After December 20th |
Early January |
Please note: Postmark dates will not be honored.
Water and Wastewater Terms Beginning H
A B C D E F G H I J K L M N O P Q R S T U V W Y Z
hydraulic grade line (HGL)
The surface or profile of water flowing in an open channel or a pipe flowing partially full. If a pipe is under pressure, the hydraulic grade line is that level water would rise to in a small, vertical tube connected to the pipe. Also see energy grade line.