SCBID TRAVELING WEED SCREEN PROGRAM Eric Dixon, P.E. Chief - - PowerPoint PPT Presentation

SCBID TRAVELING WEED SCREEN PROGRAM

Eric Dixon, P.E. Chief Engineer South Columbia Basin Irrigation District

OVERVIEW

• A look at the weed problem

– Primarily in the context of pumping plants

• Some common approaches to handling

weeds/debris

• SCBID traveling weed screen program
• Results

**Primary focus is on techniques/methods used by SCBID

THE PROBLEM…

• Weeds, more weeds, and some other stuff

– Weeds: aquatic, terrestrial – Other stuff: crops, garbage, general debris

THE PROBLEM CONT.

THE PROBLEM CONT.

• Sometimes the Debris is really big!!

Public Safety Announcement: Don’t text will tractoring…

THE PROBLEM CONT.

• So what happens???

– Intake racks blocked – pumps shut down

• Service interruptions
• Canal/Ditch fluctuations upstream and downstream
• Racks must be cleaned & pumps restarted

SCREENING/HANDLING

• Two approaches (not going to talk about

weed treatment/prevention programs)

– Manual Labor – Mechanical

SCREENING/HANDLING CONT.

• Manual Labor

– Use of rakes/hand tools by employees – Labor intensive/time consuming – After hours call-outs and overtime – Safety hazards

• Night work near water
• Physical strain

SCREENING/HANDLING CONT.

• Mechanical

– Various methods

• Automated rakers (various types)
• Rotating drum screens
• Passive screens
• Traveling screens
• Use of heavy equipment: excavators, etc.

– All three Districts in CBP using some or all of these mechanical methods.

SCREENING/HANDLING CONT.

• Mechanical

– Automated Raker

SCREENING/HANDLING CONT.

• Traveling Screens

– Simple design concept – Typical installations

• Move material in a

downstream direction

• Require structural

work in channel

• Require space

downstream for material deposit

SCREENING/HANDLING CONT.

• Traveling Screens

Cont.

SCBID TRAVELING SCREEN PROGRAM

• We are a little backwards down South

– Standard traveling screen concept but run them against the flow

SCBID TRAVELING SCREEN PROGRAM

• Why???

– No structural work required in the channel with one exception – Minimal modifications required to pumping plant structure – Material is deposited upstream away from the pumping plant for better access/cleanliness – Some redundancy is maintained with remaining bar racks

SCBID TRAVELING SCREEN PROGRAM

• The Prototype

– Constructed in-house winter 2015 – 28 CFS (12,600 GPM) pumping plant

SCBID TRAVELING SCREEN PROGRAM

• The Basics

– Box sits on P.P. apron – screen sits on box – Existing bar rack removed at box outlet – Flow over screen through box

SCBID TRAVELING SCREEN PROGRAM

• The Basics Cont.

– Epoxy coated frame and box – Polymer screen material – No moving parts under water – Small ½ HP drive motor with timer/manual control

SCBID TRAVELING SCREEN PROGRAM

• Results

– Very quick in-field installation time – Extremely reliable – Little to no maintenance – No fouling of polymer screen material

• Spray bars not required

– No pumping plant failures due to weeds/debris

SCBID TRAVELING SCREEN PROGRAM

• Results Cont.

– Example: 2019 Installation

• EB1 PP: 75 CFS

(33,700 GPM)

• Typically offline

20-25 times due to weeds/debris

• This year no

plant failures due to weeds/debris

CONCLUSION

• SCBID on 5th year of program

– Exceeded expectations – In-house construction allows us to: control costs, implement unique configurations

• Weed/debris handling remains a continual

problem for all CBP Districts.

• Various Methods, One Goal:

– Deliver water to our landowners

• Safely
• Reliably
• Efficiently

ANY QUESTIONS?

Eric Dixon, P.E. Chief Engineer South Columbia Basin Irrigation District Edixon@scbid.org 509-547-1735