# Drain Design error message ‘not downhill all the way’

<span dir="ltr" style="font-size: 14pt; font-family: Helvetica, sans-serif; color: rgb(0, 0, 0); font-weight: 400;">**Symptoms**:</span>

<span style="font-family: Helvetica,sans-serif;"><span style="font-size: 14pt; color: rgb(0, 0, 0); font-weight: 300;">When designing a drain, you receive an error message:</span></span>

![](https://docs.t3rra.com/uploads/images/gallery/2025-03/scaled-1680-/vevieiz2l3uesqrf6lpuza3hpuhqyrg49a-png.png)

<span style="font-family: Helvetica,sans-serif;"><span style="font-size: 14pt; color: rgb(0, 0, 0); font-weight: 400;">**Cause**:</span></span>

<span style="font-family: Helvetica,sans-serif;"><span style="font-size: 14pt; color: rgb(0, 0, 0); font-weight: 300;">Parameters entered do not allow drain to flow downhill all the way.</span></span>

<span style="font-family: Helvetica,sans-serif;">  
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<span style="font-family: Helvetica,sans-serif;"><span style="font-size: 14pt; color: rgb(0, 0, 0); font-weight: 400;">**Solutions**:</span></span>

<span style="font-family: Helvetica,sans-serif;"><span style="font-size: 14pt; color: rgb(0, 0, 0); font-weight: 300;">Change parameters until they produce a drain that will flow downhill all the way. i.e. increase Max Cut.</span></span>