Drainage Pond Maintenance

No Work Planned - No Problem Found - Close SR. Summary: Pond functioning as designed-email to complaintant
Details: Hello,

I'm writing to respond to a recent 311 drainage complaint
about the Grand Oaks Water Quality Pond, located along South Boggy Creek and
Menchaca Road.

The pond is designed to capture and treat the runoff from
the Grand Oaks subdivision.  The pond was
designed to maintain a permanent pool of stormwater to be treated by vegetation/biological
uptake.

https://library.municode.com/tx/austin/codes/environmental_criteria_manual?nodeId=S1WAQUMA_1.6.0DEGUWAQUCO_1.6.6DEGUWEPO

In addition, the pond is designed to detain flood flows from
the development for the 2, 10, 25, and 100-year storm events.

Any flows above the permanent pool elevation are discharged
through the large concrete outlet structure pipes and a smaller "inverted
outlet" pipe, which is what pictured in the 311 drainage complaint.

The water flowing from the outlet structure and inverted
outlet pipe was flood volume from recent rain events.  The pond was functioning as designed.

I visited the site on the afternoon of Monday 7/20/26 and
found the outlet dry and inverted outlet pipe no longer flowing, which means
the pond level has drained down to the permanent pool level.

Attached are the design plans for the pond, indicating the permanent
pool level and respective flood storage levels.

I hope that this information is helpful.

I'm happy to answer questions you may have about stormwater
ponds.

Best regards,.