Roof runoff structures are essential for diverting clean rain water around and away from contaminated areas. This course will show conservation professionals how to design and construct these fundamental structures. At the end of this course you will be able to design roof gutters and drip trenches as part of agricultural conservation projects.
Lectures are interspersed with exercises to complete on your own. A course project caps the project and ensures that that students have learned the required techniques. Students will need a printer to complete the class exercises. They should have a scanner to send in their course project but postal mail is accepted as well.
The course should take approximately 4 hours for an entry level employee to complete. Runoff Hydrology is not a required prerequisite as roof runoff structures are sized using simplified methods. Students should take this course in order to improve their conservation planning and design skills.
Why do we care about roof runoff, and what are the two types of roof runoff structures and their basic problems?
NRCS National just released this standard and NY made slight changes to it. This is the draft version but I will upload the final when it's posted to eFOTG.
Let's see how well you really understand the standard.
Roof Runoff Structure hydrology is more straight-forward than hydrologic modelling via EFH2 or TR-55. You'll learn how to go through the units conversion to produce a design flow rate for a gutter or drip trench.
The additional resource, "TR 55 Appendix B Rainfall Distributions," gives an in depth look at 24-hour synthetic rainfall distributions and why we use them.
Every gutter design needs to solve 2 problems - open channel flow in the gutter and orifice flow at the downspouts. We'll discuss general layout and then walk through a spreadsheet to do the calcs.
This lecture goes through some of the design issues that we'll face in roof gutter design. Be sure to check out the NRCS standard drawing for more specifications and notes.
Time to use what you've learned, and cover some spots that we glossed over in the lectures! Watch the lecture, then download the exercise worksheets. 1 possible solution is also posted to help check your work.
Students will learn how to take the hydrology learned previously and apply it to drip trenches.
Drip trenches are simpler than gutters, but have some specific design issues we need to cover.
A quick exercise to make sure you understand the principles of drip trench design.
Here's a simple design problem for you to work through with the spreadsheets that have been covered.
If you're taking this course to earn Conservation Approval Authority in NY, you'll need to send me a course packet showing all you did for the project. If you're not taking the course for credit, you can still send me your work and I will provide comments.
Here's a quick overview of 3 additional gutter design references, 2 of which are included here. The third is available online only at:
Tim is a NY State Registered Professional Engineer with a diverse background in agricultural conservation, civil/site design, railway design, aviation design, and highway design. He is currently the State Engineer for the New York State Soil and Water Conservation Committee housed at the NY State Department of Agriculture and Markets, where he is dedicated to improving the planning, design, and construction of conservation practices across New York State.