Common Questions about Siphons

Siphon as an Outlet Replacement

4 Key Questions that must have a Yes answer:

1. Is the dam small enough and at a low enough elevation so that the use of a siphon is physically possible?
2. Will abandonment of the original outlet works not impact the reservoir's ability to pass the required inflow design storm (dictated by regulatory agencies)?
3. Is there an alternate means to passively control reservoir level to prevent overfilling?
4. Can the siphon reasonably be used for emergency drawdown if needed (in combination with pumps in some cases)?

Other Questions to Consider

• Siphons when regular releases aren't needed
• Siphoning May Not Always Be Possible
• Low Pressure During Siphoning Can Collapse Pipe
• Pump... or Siphon?
• Siphons can pose Reservoir Level Control Challenges.

References

• Simple Steps to Siphoning
• Guidelines for Use of Pumps and Siphons for Emergency Reservoir Drawdown
• Drawdown System Selection Flow Chart

Note: The content on this page was originally created as part of DamOutletWorks.org (DOWL, 2018). It has subsequently been updated and reformatted as part of the Dam Safety Toolbox.