The 2019 Failure of the Northside Detention Basin: Where is the Public Investigation of Possible MSD Negligence?

The Cincinnati Metropolitan Sewer District (MSD) harmed the residents of the Northside community with a catastrophic dam failure.

Why hasn't there been a public investigation of this failure?

This is one multiple "do-overs" for a city agency that has an annual budget of $217.7 million dollars. At a time when COVID-19 has ravaged the Cincinnati city budget causing unprecedented layoffs of city staff we can ill afford additional failures in leadership, design, and oversight at the MSD. The number and severity of problems with the Northside project go beyond just the primarily design issues this conversation addresses and raises the further question, was the MSD negligent?

The weekend of June 15th, 2019 was a bad weekend for the residents of the Northside neighborhood when a rainwater detention basin failed due to a heavy storm. A basin is collection ditch and earth dam like structure. Dramatic flooding resulted from the out flowing waters that damaged the insides several residences and caused above ground property damage as well. 

The tragic event and its immediate outcomes were reported in the Cincinnati Enquirer. The pictures and personal stories explain the consequences of the failure.The MSD response regarding residents demanding compensation from the news article:

"[MSD Director] Christy told The Enquirer in an email that the sewer district has a team that investigates sewer backups. The flooding in Northside was caused by rainwater runoff, not sewer backups, and wasn't covered by this program, Christy said."

The question needs to be raised does the statement of the Director rejecting coverage apply if the MSD caused the rain water due to neglect or maintenance failures? MSD will have you believe it was rain water only but once the flood is in the basement the sewage will perk up into the basement. It was in the financial interests of the MSD to say the event was just rainwater to prevent a hit on the city budget. Did this cause a conflict of interests when the MSD makes determinations on itself? 

While this basin failure was not primarily a 'sewer backup' it was a dam project to prevent sewer overflows with the MSD designing and contracting the project. This project overview is on display at Project Groundwater:

Proposed Basins as described at Project Groundwork

The three key points from the Project Groundwork overview written by the MSD:

1. The Challenge in Northside When it rains, stormwater enters combined sewers in the vicinity of Kirby and Virginia avenues. If the sewers become too full, sewer overflows can occur at CSO 125... About 188 million gallons of raw sewage and stormwater overflow annually from this location. 
2. The Solution in Northside MSD is designing two stormwater detention basins — North Basin and Martha Basin — off Kirby Avenue that will keep stormwater out of the combined sewer system...
3. Each basin is designed to hold stormwater from a 100-year storm.

That the MSD is responsible for the designs of the system is also found in the contract for Project ID 10240018 CSO 125 Stream Separation:

"Modeling or other analysis to estimate [Combined Sewer Overflow] CSO volumetric control at CSO 125 except showing the results of the completed project by modeling the completed design with the calibrated model to be provided by MSDGC." 

The Metropolitan Sewer District intended to design a system to solve a problem at one of the Combined Sewer Overflows that had been overflowing human waste contaminated rainwater for years at a specific location, Combined Sewer Overflow 125, in the Northside community. 

The details that unfold with the April 2020 after-action engineering report that released ten months after the dam failure presents the project as having many design, construction, and oversight failures:

1. The North Basin does not include a spillway designed to protect the embankment from breach and channel excess flow safely downstream.
2. The design of the North Basin Outlet Structure may provide less capacity to utilize the Combined Sewer than existed before the project. This may have contributed to washout of the embankment and to increased flooding during the June 2019 event.
3. The North Basin embankment was under construction at the time of the June 2019 event, and it is unclear whether the embankment was completed to its full height before the June 2019 event. If the embankment was not at its full height, this could have decreased the flow conveyed by the existing 96 inch combined sewer and increased the flow over the embankment.
4. In addition, while not confirmed as a factor in the June 2019 flooding, the design greatly underestimates the flow from the design storm, posing a risk of increased flooding during future significant rain events. Specifically, the North Basin does not have sufficient capacity to protect against a 100-year storm, as required by the design documents. Engineering calculations and an MSDGC modeling run conducted as part of this review suggest that the Basin should be designed to handle a 100-year design flow ... [an] estimate [that is] is approximately 67% higher than the [calculation] used to design the North Basin.

The MSD took the scathing report and created a marshmallow summary memo to the Cincinnati City Manager. The memo, written by MSD tones down MSD's own responsibility in the project and casts blame to the contractors. The memo to the City Manager makes no mention that the model showed the project undersized by 67%. The basin design never met the required design goal for a 100 year storm. The MSD memo further asserts the contractors are not accepting responsibility for the failure. A narrative the primary contractor refutes for many reasons including their response the MSD provided a bad calibrated and validated model... that the MSD contract required design was wrong. 

The MSD memo to the City Manager makes additional statements that contradict the MSD's own design documentation.

The MSD created design document, MSD Recommendation of LMCPR Alternative 2012, says on page 93: 

"The intent of the sustainable projects is to design detention basins that are not classified as dams or that minimize dam impacts." 

Why would a contractor go against the design document? They wouldn't...but the MSD tries to throw the contractor under the bus anyhow in their memo to the City Manager:

"[the contractor] admits that it designed the facility with insufficient capacity and that it modified the design (without MSD’s knowledge) so that it would not be subject to Ohio Dam Safety Rules..."

This statement from the memo to the City Manager by the MSD directly contradicts the MSD created design documentation! It was in the MSD design document that the basins were not intended to be subject to Ohio Dam Safety Rules. 

The four major points from the engineering report were reduced to one sentence in the MSD letter to the City Manager that completely misrepresents the project's failure: 

 "...it does appear likely that some design modification will be required in order to ensure flood protection."  

The four bullets from the after-action report above make it clear the failure was much more than "some design modification" required, it was a complete breakdown of process. Someone had to approve each step of the project, someone had to oversee the project, someone even had to approve water being allowed in the basin before completion. The day after the failure the berm is being repaired...was the soil ready or appropriate for that repair? Is Northside at risk of another failure? The 'someone' that had oversight was supposed to be the MSD.

How and why the Cincinnati Metropolitan Sewer District failed the Northside community to this extreme needs to be investigated by a third party and made transparent through a public report. Oversight of the MSD needs to increase, not decrease as requested by the MSD, from Hamilton County.


The Google Drive share for the following documents obtained through Ohio Open Records Law and Freedom Of Information Act requests:

CDM Smith response to MSD September 19 2019
Memo Diana Christy Director MSD to Patrick Duhaney City Manager April 8 2020
MSD Recommendation of LMCPR Alternative 2012
Project ID 10240018 CSO 125 Stream Separation October 15 2015
MSDGC West Fork CSO 125 Project June 15-16 2019 Flood Event Investigation April 3 2020