Lessons Learned: Catastrophic Sediment Basin Failure Adjacent to the Catawba River

This presentation is based on an ongoing case study at a residential project under construction in Charlotte’s Critical Watershed. In August 2017, a dry-weather embankment failure resulted in the rapid release of nearly 1.5 million gallons of impounded water from the active construction site. This caused severe offsite sediment impacts to an adjacent tributary and threatening the nearby Catawba River. This unexpected failure in a critical area, along with the severity of impacts presented a myriad of challenges for local regulators. The City of Charlotte had to oversee the cleanup efforts and remediation of approximately 700 cubic yards of sediment that had been deposited across the state line and onto multiple private property owners. Determining the cause of failure and assessing the post failure safety concerns was critical and required extensive coordination among multiple jurisdictional entities. Additional unforeseen challenges included managing information and messaging through multiple agencies, working with disgruntled private property owners, and determining downstream impacts in a receiving cove of Lake Wylie. This presentation will explore these challenges and elaborate on the lessons learned from this failure from a local government regulatory point of view.

Learning Objectives:

1. Identify potential deficiencies with embankment construction and skimmer basin installations.
2. Assess offsite sediment impacts and determine the scope of remediation if necessary.
3. Propose a rudimentary remediation plan and course of action to remove significant amounts of offsite sediment.

Course Level: All

To receive credit for this class you must listen to the entire presentation, complete the course quiz with a passing grade of 70% of better and complete the course evaluation. After all course components are complete - you will receive 1 Professional Development Hour of credit.