Taming the flow
By EMILY FEATHERSTON and ALYX CHANDLER
Though it serves as a popular spot to launch a canoe, wade on a hot summer day or even hunt for fossils in the drier season, the Cahaba River access off Old Overton Road is also a gateway to one of Alabama’s most critical resources.
At 194 miles long and with a watershed encompassing more than 1,800 square miles, the Cahaba is the state’s longest free-flowing river. It is also considered to be one of the 10 natural wonders of Alabama, according to the state department of conservation, and is recognized by the World Wildlife Fund as one of only eight “hot spots” for biodiversity in the world.
The Cahaba is also the largest source of water for the Birmingham Water Works Board in serving the over the mountain area, and as development continues in Jefferson and Shelby Counties, the concern about the health of the upper river basin has grown as well.
David Butler, a representative for Cahaba Riverkeeper and owner of Canoe the Cahaba, said that he and others see it as a delicate balance.
“It’s a really difficult problem to resolve because I think it’s universally recognized that water is a fundamental building block for any community,” Butler said. “If you can’t provide water, you can’t sustain life.”
But, as the river grows in popularity and development on and near it increases, he and others are concerned that the river itself has already begun to suffer.
“We think it’s great that everyone loves the river but we are kind of loving the river to death,” he said.
At those meetings, Butler, along with Riverkeeper President Peggy Gargis and environmental biologist Janna Owens, expressed grave concerns not only about the development in question, but about the precedent it would set for developing along the river.
“I would say that this project has been done with due diligence, but we have to be considerate of [the] water system going forward,” Owens said at the meeting, referring to the steps developers had taken to protect the river.
Those steps focused on stormwater runoff mitigation, arguably the most significant danger Butler and others said the Cahaba faces.
Stormwater is any rain, snow melt or other large flow of water that runs untreated into a storm sewer system.
In significant or sudden rain events, a “first flush” of water collects and flows quickly through the storm sewer system into creeks and rivers, often carrying debris, contaminants and other pollution with it.
“What has been the practice in Alabama for a long time is to sort of evacuate the water from those developments as fast as possible,” Butler said, “so you have all these storm drains and gutters and everything else that channels the water into the river at an unnatural pace, and it doesn’t have the chance to soak intothe ground.”
Stormwater management is not a new concern, said Vestavia Hills City Engineer Christopher Brady.
In the early 1990s, the municipalities in Jefferson County came together to address the issues in the 1987 Water Quality Act, forming the Storm Water Management Authority (SWMA).
At that time, Brady said, the state issued the group a stormwater management permit – meaning that the municipalities could issue permits to developers using one set of guidelines.
But in the time since, Brady said the state determined that permits should be more specific and determined that each municipality needed to go through its own process.
Vestavia is currently in the process of moving to a more stringent permitting process, known as MS4.
In the greater Birmingham area, only Trussville currently has and operates under an MS4 system, but other municipalities are moving in the direction.
“We are still working with SWMA and other cities in the area so that we are consistent,” Brady said, but added that city employees are looking and putting together a plan to begin following the MS4 rules once the permit isin place.
The city received approval from the state in June, effective July 1, and has one year to bring the city’s ordinances and processes up to par.
The purpose of the MS4 is to control the water that results from sudden and significant rain events, working to have that water filter through permeable ground or artificial filters to eliminate pollutants and debris.
Much of what is in the MS4 is similar to steps the city took in 2010 when it reworked its zoning codes, but Brady said that the major change is that current system doesn’t quantify the amount of stormwater that needs to be controlled.
In the new requirements is the mandate that the first 1.1 inches of rain, what generally constitutes a “first flush,” is controlled.
While the city’s current regulations say that the “first flush” must be controlled, the MS4 further defines exactly what is required.
“Now we’ve got a hard-written rule,”Brady said.
Even before receiving the MS4 from the state, the city has been working with developers during the rezoning process to attempt to move toward the pending change.
During the discussions about Helen Ridge, Brady and engineers for the developers said that the subdivision as planned would control the first 1.2 inches of rain, which would be more than required by MS4.
With more definable regulations, Brady said municipalities can better protect water quality.
But for river advocates, questions remain, particularly about the effect development at the top of the basin has on the river asit moves south.
“The biggest impact, unquestionably, is development – the rapid expansion of the communities that surround the rivers,” Butler said.
Whether it’s pollution and trash that inevitably float downstream, or displacement of sediment due to the higher velocity flows that result from stormwater runoff, there are visible effects advocates say development has on the Cahaba.
Even if pollution is controlled, development usually increases the volume of water and the speed at which it reaches the river, which Butler said can erode banks and create major problems for the river's ecosystem.
“That’s the other important part of this discussion, more than anything else we do, rivers connect communities in a way that almost nothing else does. It’s sort of an interstate or highway,” Butler said.
And while the city may be moving to a more strict permitting system, there are also ways Butler and others said citizens can make an impact individually.
Alabama Rivers Alliance Program Director Mitch Reid said he encourages people to find places to live in Vestavia that were developed using “Low Impact Development,” which refers to practices that use or mimic natural processes that result in the infiltration stormwater. It is also referred to by the EPA as green infrastructure.
By utilizing developers that use green infrastructure, runoff regulations are followed and residents show support for the Cahaba and other rivers through their choices and wallets,Reid said.
Butler and Reid agreed they think cities like Vestavia need to be doing more than holding developers to runoff regulations.
Butler and other advocates for the Cahaba are currently in talks with the city about the future of the former Altadena Valley Country Club, which the river runs through, and said he hopes the city will leave it as a passive space to act as a buffer for the river.
“Vestavia has this huge opportunity right now to do something that has a generational impact,” Butler said.
He added, “at some point you have to take a stand and make some changes or else these impacts we are fearful of in the future will become reality much quicker.”
For more information about the Cabaha Riverkeepers' efforts, visit their website at
cahabariverkeeper.org. For more information about the MS4 permit, visit epa.gov/npdes.