Southlake subdivision is a development located on one side of Indian Valley Lake with the Cahaba River bordering the other side of the development. According to a resident and history buff, construction of the lake began in 1972 at a cost of $729,000. The lake was 110 acres and had seven miles of shoreline. The lake is fed by Acton Creek and was defined as anything below 423 feet above sea level regardless of the water levels of the lake . By 1989 Southlake was part of the ever-expanding city of Hoover. There are homeowners and lake associations representing various constituents around the lake. In 2008 the Spain Park detention pond dam failed and dumped water, sediment, and debris into the lake. This and other flooding have reduced the size of the lake by ten acres. There are places in the lake that now appear to be sandbars, inlets that once allowed lake access are full of debris and sediment, and lots that have been covered by sediment and debris flowing from overwhelmed stormwater infrastructure, for example, clogged curb inlets. Lake residents have worked with Cahaba River Society to address the environmental issues and met with city officials and staff with little to show for their efforts. For ten years the residents have reported silt runoff during one-third to one-half inch rains; they have documented over 20 incidences of relatively small rain events causing major silt, sediment and debris run-off into the lake. Generally, the city has indicated that the infrastructure was not built to plan and that these problems are private property issues.

Southlake subdivision is located in Hoover and Shelby County. Therefore, Southlake is served by a Hoover sanitary sewer with a contracted manager. The system comprises nine pumping stations, a sewage treatment plant near the Cahaba, a backup generator, and a telemetry system. There are 40 sanitary sewer manhole covers set at 425-430 feet above sea level and near the lakeshore in addition to others further from the lake. During rain events, these covers are routinely flooded over allowing stormwater to enter the sanitary sewer and the sewage leaks out onto yards and into Indian Valley Lake. The lake feeds into the Cahaba River. When the rain raises the lake level by two or more feet many of the sanitary sewers are inundated and sewage leaks from the covers. This also happens because stormwater is not controlled by the stormwater infrastructure so even at normal lake levels the lids are compromised and leak. Stormwater has left sediment and debris around the manholes thus raising the level of the land around the manholes so that with each rain it is easier for water to flood the manholes and release sewage. In addition, the multiple “fail-safes” that are in place have failed at the same time in certain events. Since 2017 the sanitary sewer pumps have failed four times. For example, the system is supposed to trigger an alarm, and notify the city. This failed in 2016 and homeowners reported the failure to the city. The response was “the solution to pollution is dilution”. On October 6, 2021, flooding and sewage leaks were repeated. The city has spread lime on private property to treat the sewage leaks and E. coli. The lake has high levels of E. coli bacteria. It is possible that the routine maintenance and checks of the system were not completed. October 6 was not the only time the system failed, nor the only time raw sewage was released at Southlake. Clearly, the city knew of the issues with the sanitary sewer at Southlake and has had a less than satisfactory response, particularly in saying “dilution” is the solution.

There are several solutions to this problem. One is to re-grade around the manholes. Of course, that only works in the long term if the stormwater infrastructure is also repaired or upgraded to reduce or eliminate the flooding from roads and easements. Another approach would be to replace the manhole covers with sealed covers that are bolted in place. Regular inspections, tests, and maintenance of the system (pumps, alarms, etc.) are necessary for either solution.

In the Future Hoover plan (the comprehensive plan) the city designates Southlake as a catch basin to protect the Cahaba. Indicating that the lake will need to be dredged as part of the plan. Clearly, the lake is already a catch basin and the city has recognized that but has not accepted responsibility for maintenance. No matter who or what has led to the inadequate stormwater infrastructure at Southlake the problem must be addressed. Most of the infrastructure is under city streets and that drainage system has caused erosion downstream. Further, construction has contributed to the sediment as silt fence was sometimes not properly installed during land clearing activities. In some situations residents reported this to ADEM. E. coli, and other pollution feeding into the Cahaba is a public health issue and should be a priority for the city.

The city collects taxes from Southlake residents, and fees from builders, and thus has a responsibility to residents to maintain the land and lake as it was when residents built their homes.