Propping up Lake Purdy’s pool

Less than 70 million gallons — not even the amount Birmingham Water Works distributes to its 600,000 customers in a day — is what stood between Lake Purdy’s November levels and its reserve pool. 

The lake, which, along with the Cahaba River, provides water to Birmingham Water Works customers in the southern part of Jefferson County from Liberty Park to Alabama 119, reached a low point of 26.2 percent of full pool following months of drought.

While Lake Purdy was back up to full pool — 5.59 billion gallons — by mid-April, the drought brought conversations about ongoing BWWB projects back to the spotlight, including work on the Carson Loop. The Carson Loop includes thousands of feet of pipe that will connect to the Carson Filter Plant in Pinson, bringing water from north Jefferson County to over-the-mountain communities. Planning and discussion about the Carson Loop started in the mid to late ’80s, when the southern part of the county saw immense growth, said BWWB Assistant General Manager Darryl Jones. 

Most areas on the BWWB system can be served by two water treatment plants or more, but areas south of town are not as easy to service from multiple plants, he said.

“We struggle with that,” Jones said, “because that’s just how the system grew. We’ve put probably 15-20 miles of pipe in the ground so far, to bring the Carson Loop, to bring water to south of town. It’s taken a long time; it’s taken a lot of money.”

Projects like the Carson Loop bring redundancy into the system, preparing for both growth and emergency situations.

“The only plant that can supply the southern part of the system effectively was the plant on Highway 280, so if anything happened — a contamination of water, prolonged power outage, things that could limit a plant’s production — the southern part of the system would be somewhat in jeopardy,” Jones said.

The extra pipe also can lead the BWWB to be less reliant on other water systems during a state of emergency or drought. 

Its intention is not to make the area drought-proof but to add another connection and water source to help strengthen the system overall, he said.

“It is our best man-made effort to strengthen our system to have a positive impact, but we will still have to have a drought-management plan,” Jones said.

Birmingham Water Works has partnerships with neighboring systems, and those systems will sell each other water to ensure customers are receiving a clean, constant stream, Jones said. During this drought, the BWWB purchased nearly $1 million in water over about 50 days from Shelby County Water Services.

The Birmingham Water Works system runs adjacent to Shelby County’s system, down U.S. 280 and Alabama 119, and there are places where BWWB and Shelby County Water Service can connect along Alabama 119, said Shelby County Water Services Manager Michael Cain.

“There have been a couple of times [the connections were used],” Cain said. “Shelby County actually needed their [BWWB] assistance when we’ve had some situations at one of our water plants, for a short period of time. They’re set up for emergencies, whether it’s drought conditions that we’ve had or short term  conditions like we’ve had.”

In this drought, the partnership with Shelby County helped relieve some of the pressure on BWWB’s Shades Mountain Filter Plant.

Because the Birmingham system pulls water from four sources and each source can be affected differently in a drought, connecting to more than one plant opens the option of pulling from a different source, rather than buying water from another system, Jones said.

“We do have a surplus of water in certain parts of the system, and this gives us the opportunity to take that surplus water to feed into an area that has some shortage of supply,” Jones said. “If the demand is greater than what it can produce, then we still have those agreements.”

Cain said it also benefits neighboring systems that might need the extra help a better-connected partner system could provide.

“If Shelby County really got into a bind for some reason, they would have the ability to provide any of the extra volume of water through that system as well,” Cain said. 

Areas such as Liberty Park, which can put a higher strain on the system due to population and topography, also will receive a redundancy in their water system, protecting against a loss of water service.

“Liberty Park is a big subdivision, a big development area, and the way the Carson Loop is routed, we’re going to be able to strengthen that area by having more than one way to feed that area,” Jones said.

Water travels into Liberty Park through the main entrance, and then the pipe dead ends. If anything happened to that pipe, all of Liberty Park would be out of water, Jones said. The extra pipe along Sicard Hollow Road provides a second path for water.

With initial plans on the Carson Loop, sections of the pipeline were projected to be completed in 2015 or sooner. A variety of factors, however, delayed those plans, Jones said.

To install new pipes, the BWWB must obtain easements for private property, coordinate with the Alabama Department of Environmental Management, address environmental factors that cause a pipeline to be rerouted and approvals from municipalities the pipe runs through.

“There’s a lot of moving pieces to it,” Jones said. “Just because you’re the water utility doesn’t mean you can drop pipe wherever you want to. There’s no one particular thing that delays the project.”

This project also was affected by the Great Recession, Jones said. 

“Funding kind of dried up for a period of time until we were able to go back to the bond market and get money to get back on projects,” he said.

Phases of the project are broken up according to funding, Jones said, to obtain the necessary funding, complete one of the phases and then seek more funds for future phases. 

During the drought, the BWWB was able to install phases 8B and 8D under Lake Purdy, about 0.44 miles of pipe. Thanks to the low lake level in 2016, the pipeline was installed more easily. Future legs 8A and 8C will connect Alabama 119 to Lake Purdy and the north end of the lake to the pipe along Sicard Hollow Road, respectively. Those projects will add a total of 1.29 miles of pipe. 

The 36-inch pipe that comes from the Carson Filter Plant branches into three legs of slightly smaller pipe. Within the next year or so, Jones said they plan to have one of those legs complete.

While the Carson Loop will address some issues of need on the system and help supplement the current system, Jones said it will not be the end of BWWB’s work to meet customer needs.

“That’s one of the things the Carson Loop is going to do — it’s going to continue to give us the ability to supply water to an area that doesn’t have as much redundancy, for sustainability reasons, as other areas, but once we accomplish that, there will be new goals, new hurdles to accomplish,” Jones said.