⚠ May force water along outside of pipe

Message: Sliplining perforate CMP can be problematic because water may be forced through the embankment instead of passing through the pipe.

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  The old CMP was sliplined right before weather shut down the project. The filter seepage control diaphragm was not installed in time and was planned for the following spring.

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  The old CMP was sliplined right before weather shut down the project. The filter seepage control diaphragm was not installed in time and was planned for the following spring.In early spring, water began to move around outside of pipe. The original pipe had holes due to corrosion, which allowed the pipe to act as a drain, moving water from the embankment into the pipe. The dam was in equilibrium due to the perforations. When the pipe was sliplined, water was forced to find another place to go (i.e. along outside of pipe).

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  Water is shown flowing along the outside of the conduit during the spring following sliplining activities.

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  In this particular dam, following slip lining of the original pipe seepage began to appear on downstream face of the dam

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.
Revision ID: 3165
Revision Date: 09/15/2022