Booker Creek Flood Mitigation Project Placed on Hold in Response to Resident Concerns

COMMUNITY

By Hannah Olson

Residents came out in full force this week to express their affection for the forested areas along Chapel Hill’s Booker Creek and to voice opposition to the proposed removal of about 50 acres of trees along the creek. As a result, plans to mitigate chronic flooding in the Lower Booker Creek watershed by constructing several stormwater retention basins in both the upper and lower sections of the creek are on hold. These basins, recommended by an engineering firm the Town hired to find ways to reduce flooding, have been controversial among area residents, due to their environmental, aesthetic and financial impacts.

On Monday, Sept. 13, dueling presentations between the Booker Creek Neighborhood Preservation Alliance and the engineering firm WK Dickson painted a picture of a community in agreement on one thing — the flooding needs to be mitigated — but at odds over what form the mitigation should take.

More than 250 people logged on to observe the virtual meeting.

Chapel Hill Mayor Pam Hemminger opened the meeting by attempting to put the concerns of many at ease.

“We know there’s been a lot of community interest in this topic,” she said. “We are not voting on anything tonight. This is a chance for us to communicate and hear from folks in the community as well as from our consultants. I know that a lot of you have been distressed about this situation. The plans that were presented to the council have been put on hold. We are not proceeding.”

Longterm issue, longterm solutions

Flooding has long been an issue in the Lower Booker Creek subwatershed. In the northern part of Chapel Hill, the Booker Creek watershed covers approximately 1,130 acres or 1.8 square miles of land, and generally drains north to south discharging to Little Creek.

Flooding problems have been exacerbated in recent years by the increased frequency and severity of heavy precipitation events as well as increased development, which replaced trees and soil with impervious surfaces like roofs and pavement, in the upper part of the watershed.

In 2014, the Town of Chapel Hill adopted a Stormwater Master Plan with the following goals:

• Address stormwater quantity (flooding);
• Address stormwater quality;
• Protect and restore natural stream corridors.

In 2015, Chapel Hill hired the WK Dickson engineering firm to analyze the watershed and make recommendations to reduce flooding. The firm’s Lower Booker Creek Subwatershed Study, published in 2018, evaluated how stormwater is currently managed within the subwatershed and how future development may affect the ability of existing infrastructure to convey stormwater. The study also recommended various stormwater management improvements, including the removal of riparian forest buffers and excavation of tons of soil to increase stormwater retention capacity at several points in the watershed.

In a presentation kicking off the meeting Monday, WK Dickson’s Tom Murray walked the public through some of the highlights of the previously published study and provided some context for the decisions the Town must make.

“We all know that this watershed is developed. It is impaired at certain locations, both from a quantity and quality perspective,” Murray said. “It’s estimated that approximately 22% [of the watershed] is impervious area. That’s noteworthy because, according to the Environmental Protection Agency, watersheds can begin to become impaired in the 6%-10% impervious range.”

Murray spoke about some of the unique challenges of addressing flooding in the Booker Creek watershed.

“One of the challenges is that we have some steep slopes in the upper portions of the watershed, and then we have some low-lying flat areas downstream near Eastgate shopping center and Fordham Boulevard and Willow Drive,” Murray said. “During a high-intensity rainfall event, water flows very quickly [in the upper portions of the watershed], but then it slows down and that’s part of why those [low-lying] areas can become flood-prone.” Another challenge, Murray stated, is that “The native soils have low infiltration rates. Water is less likely to soak in the way we would like it to, especially on the steeper areas.”

The firm’s report recommended 11 primary projects to address flooding, seven of them being floodplain storage basins (see map).

“I know there’s been a lot of concern about the floodplain storage areas and we certainly understand that,” Murray said. “We want to make sure we’re developing resilient solutions. One of those is floodplain storage, which allows the stormwater runoff better access to the floodplain.” This better access, he explained, would slow down the runoff at peak flow, which would reduce the stress on the stream banks and promote nutrient removal by allowing the water to remain in the floodplain for a longer period of time than it would otherwise.”

The highest priority storage basin project, according to the WK Dickson study, and the only one that has been constructed thus far, is the Elliot storage basin that lies between S. Elliot Road and Eastgate shopping center. This flood storage facility includes pedestrian amenities and has been developed as a park with a walking path that links the shopping center to a new apartment complex.

When asked about the effectiveness of the Elliot storage basin, which was completed about a year ago, Murray responded, “From what we’ve seen so far, it does appear to have been effective,” but acknowledged that the facility has not yet been tested by the kind of intense precipitation event that have caused severe flooding in the past. “So it’s something that obviously we would recommend the Town continue to monitor.”

The Town of Chapel Hill had been preparing to construct some of the other high-priority flood storage basins WK Dickson recommended, but when residents of the areas that would be affected by the projects learned about the potential loss of trees and associated ecological and aesthetic impacts, some expressed concern.

Residents mobilize to oppose flood storage basins

WK Dickson elicited input from community members in 2015 and 2016 as part of the subwatershed study. At that time, some residents raised concerns about the idea of transforming sections of creek corridor into flood storage basins, but neither the Town nor the consultant followed up on these concerns. In 2018, the firm published its final report containing their recommendations, including the 11 storage basin projects. When residents living near the proposed flood storage areas learned last summer that the Town had given the go-ahead to begin construction of the basins, they organized the Booker Creek Neighborhoods Preservation Alliance (BCNPA) to oppose the projects.

Representing the BCNPA Monday, were Dr. Edward Marshall, Dr. Douglas Frederick, John Morris and Michael Dupree.

“We didn’t find out until early July of 2021 that six of our neighborhoods were going to be clear cut, excavated, and turned into grass and concrete basins,” said Marshall. “We’re a group of neighborhood experts with many decades of experience in hydrology, forestry, biodiversity, green infrastructure, economics and leadership.

The group cited environmental concerns, primarily wildlife habitat destruction, deforestation and heat islands.

In the presentation, the four representatives laid out 23 alternative solutions to floodwater issues, compared Chapel Hill’s floodwater management to that of Durham, and pleaded with the Town Council to cancel the proposed storage basin projects in favor of adopting a comprehensive green infrastructure policy and strategy to mitigate stormwater.

“For the sake of our children, and for the future of our community. We’re asking for three things: First, to permanently remove all six approved neighborhood stormwater basins from the town stormwater plan. Second, to adopt a comprehensive green infrastructure policy and strategy, not just a working group, but a policy and a strategy,” Marshall said. “And third, to develop that policy to create an independent green infrastructure task force.”

Marshall said while WK Dickson did what they were commissioned to do in completing the study, there was more that needed to be done.

“They did what they were asked to do and they did a great job. It’s 500+ pages,” he said of the study. “What’s missing is an environmental impact analysis, an ecological impact analysis, a climate change analysis, a neighborhood impact analysis and a cost-benefit analysis. While some alternative green infrastructure was mentioned [in the study], we’re going to suggest a much more robust approach.”

Morris, former director of the North Carolina Division of Water Resources, questioned whether the costs of the project exceed the proposed floodwater mitigation benefits. “Dickson has not shown how much these projects would actually reduce flood damages,” he noted. “Dickson cites only reductions in flood levels in terms of tenths of a foot, not the amount of damage to structures that would be avoided. This information is fundamental to flood control studies, but it’s missing here.”

“There are many more cost-effective ways to target assistance to homeowners who actually experience repeated flood damage than this costly and environmentally damaging project,” he said.

The BCNPA slide presentation can be downloaded here.

Many Voices, One Message

Dozens of community members spoke during the meeting, citing wildlife, love of recreation, home value concerns, worries about children’s safety, aesthetics and more.

The spoken public comments included the following:

“I live on Ridgefield Road and my home is directly adjacent to the stormwater drain that takes the water from Ridgefield Road down to Booker Creek in an open-air ditch,” David Hartman said. “When flooding does occur, I get it from two directions — from the rising Booker Creek and also from that open-air drain. I have managed to control water from coming into my home by various mitigation procedures but my flood insurance is still $6,000 a year. All of that being said, I would prefer almost any solution, including no solution at all, than to cut down that beautiful forest that makes up my backyard and all of its water-absorbing trees.”

“The deforestation of the Lower Booker Creek subwatershed is an irresponsible and damaging act without a thorough environmental impact report and a clear cost-benefit analysis. By continuing without those reports, you’re not only spending $19 million of taxpayer money but also setting the precedent that future projects can be done without these analyses, potentially causing harm to the citizens of Chapel Hill,” Lillian Zwemer said.

“I bought my house adjacent to the Booker Creek riparian buffer because I love flowing water, I love the woodlands around the creek,” said Jameson Wildwood. “There’s a mated pair of barred owls who live in these woods. I know because I hear them calling each other every night. These owls mate for life and maintain their nest for many years; this crucial habitat is their home and they need the mature forest and creek to live and thrive.”

“The cost of these basins is more than just the $20 million of taxpayer money with little assured benefits, as we heard costs include loss of mature forests that provide stormwater mitigation and carbon sequestration, protection from heat. I would also like to add that there is an important quality of life cost: it’s now well documented in research studies that spending time in a natural forest environment increases a person’s reported sense of well-being and decreases reported feelings of anxiety and depression,” Martha Cox added.

Even more comments came in via email (see comments submitted through Sept. 8 here), such as the following:

“The problem of Booker Creek flooding initially started with building a shopping mall on top of one of the defining waterways of Chapel Hill, and the solution possibly lies in the same areas,” Chapel Hill resident James Jollis wrote, citing the words of a Joni Mitchell song: “They paved paradise to put up a parking lot.”

At the end of the meeting, the resounding voices of opposition were clear — do not move forward with the proposed storage basins.

What’s Next?

The issue remains far from settled. As promised, no decisions were made at the Sept. 13 meeting. The Town Council will next address the matter in October.

“We heard you,” Hemminger said at the close of the meeting. “The plan is on hold, we’re going to put this working group together, we’re going to figure out some paths forward. We love the engagement we’re hearing from people that we haven’t heard from in a long time or ever.”
At its Sept. 22 meeting, the Town Council will act on BCNPA’s petition to withdraw approval from the storage projects and will consider how the working group to be set up to develop new stormwater alternatives will operate.

BCNPA will present its concerns to the Town’s Environmental Stewardship Advisory Board Sept. 23 at 7pm. To register for this meeting, visit https://bit.ly/3lA5hyg.

The Town Council will hold a public work session Oct. 20 2021 for staff to provide an update on the subwatershed studies and a compilation of questions and comments received by the Town from residents and staff’s prepared responses to the questions.

Footage of the Sept. 13 meeting can be viewed at https://bit.ly/2VYchw4. Public comments can be sent to: stormwater@townofchapelhill.org.

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Update: At its Sept. 22 meeting, Chapel Hill Town Council voted to withdraw approval of the six Booker Creek stormwater basins and created a working group of community members, advisory board representatives, experts and staff to help the Town devise a new plan to address flooding in the Booker Creek watershed.