An engineering firm gave the Brookhaven City Council bad news about the Nancy Creek Watershed, saying the creek is unsafe according to state standards and has been contaminated with fecal matter, likely from county sewer overflows.
The price tag to repair the damaged watershed and address other concerns, including trash in Murphey Candler Lake, is $19.4 million.
The report was presented to the City Council at its Aug. 9 meeting by the firm Sustainable Water Planning and Engineering, which the city hired last year.
Councilmember Linley Jones said the plan represents a “turning point” in caring and repairing the watershed.
“The watershed has gone without any attention for decades and now we have a plan,” Jones said.
It is an expensive plan to fix the watershed, Jones acknowledged, but that cost is expected to be stretched out over 20 years. In the meantime, the city can take out “bite-size” chunks.
One possibility is using stormwater fees, plus grant money, to repair the shoreline of Murphey Candler Lake. The cost of that project is $123,000 and can be completed in about three years, Jones said.
Residents brought the issue of the deteriorating watershed to city officials in recent years, discussing their concern over the loss of fish and lack of wildlife. As the city works to reclaim the watershed, Jones said she hopes homeowners also take pride in the environment and watershed, much of which is located on private property, to care for the land.
“This will make a big difference,” she said.
A watershed is an area of land that catches rain and other forms of precipitation and drains or seeps into a marsh, stream, river, lake or groundwater.
The upstream portion of the Nancy Creek Watershed includes portions of Dunwoody, Doraville, Chamblee and Sandy Springs, as well as Brookhaven, the report explains. From Brookhaven, Nancy Creek continues to flow southwest through Sandy Springs and Atlanta before it joins Peachtree Creek and then flows to the Chattahoochee River. Water from the Nancy Creek Watershed eventually reaches the Gulf of Mexico.
The plan presented to the Brookhaven City Council focuses on the upper Nancy Creek Watershed, which is delineated from the downstream boundary of Brookhaven, where Nancy Creek exits Brookhaven, states the report.
The study area covered 19.3 square miles, or about 12,300 acres, over eight different subsections of the watershed. In Brookhaven, those areas include Bubbling Creek; Nancy Creek’s North Fork and main stream; Perimeter Creek; and Silver Creek. The study area also includes drainage from Chamblee, Dunwoody, Doraville and Sandy Springs.
The main tributaries in the watershed as stated in the report:
North Fork Nancy Creek that flows south from Dunwoody and is located to the east of the Perimeter Mall area. The dam on North Fork Nancy Creek at West Nancy Creek Drive created Murphey Candler Lake. The lake is just upstream of the confluence of North Fork Nancy Creek with the primary Nancy Creek downstream segment.
Bubbling Creek originates in Chamblee and flows northwest to the confluence with Nancy Creek.
Perimeter Creek originates in Dunwoody to the west of Perimeter Mall and receives most of the drainage from the Perimeter Mall area. A major tributary of Perimeter Creek flows southeast from Sandy Springs near Northside Hospital and joins Perimeter Creek just inside Brookhaven. Perimeter Creek flows south and west to the confluence with Nancy Creek.
Silver Creek is the name assigned to an unnamed tributary stream included in the report. This stream includes Silver Lake and Little Silver Lake.
There are three ongoing watershed concerns the report says need to be addressed:
►Trash and debris: Trash including plastic bottles, cans and other floatables is a concern, especially within Murphey Candler Lake, the report says. Trash from I-285 flows down North Fork Nancy Creek and into Murphey Candler Lake. The trash accumulates in the lake’s upper coves, and trash that is washed into the lake is blown by the wind into the eastern cove. Volunteer groups periodically remove trash via a canoe, but those efforts are not consistent or sustainable, according to the report. A better solution, the report says, would be “floating trash racks” that are attached on the downstream side of a culvert to catch the trash before it enters into the waterway. Cost of a trash rack is $50,000. The plan proposes four trash racks just north of Murphey Candler Lake.
►Streambank erosion: Erosion results in the loss of private property, and the eroded sediments are deposited downstream, negatively impacting stream habitat, the report says. Planting hardy and native vegetation along shore banks can help reduce erosion. Stream enhancement projects, such as stabilizing stream banks with logs, can help reconnect a stream with a floodplain and improve the quality of the watershed.
►Stormwater and drainage concerns: Complaints to the city are numerous about erosion, infrastructure and maintenance, the report says. There are only 108 stormwater management features within the Brookhaven portion of the watershed to drain an area of approximately 3,025 acres. Since most of these features are intended to serve drainage areas less than 1 acre, much of land area is uncontrolled, the report says. In a developed watershed, like Nancy Creek, there are relatively few opportunities for larger stormwater management features, which means that a larger number of smaller features will be needed. The overall impervious area in the Nancy Creek Watershed study is 38 percent. Studies show that watersheds with impervious area greater than 25 percent have degraded habitat conditions.
Pollution and bacteria are also concerns, the report says. There are many pollutants in the watershed area, likely because there are more intense land uses such as commercial, industrial and roadway, and few stormwater management features in the study area.
Murphey Candler Lake also has too much fecal coliform bacteria, according to state standards. According to the report, the DeKalb County Watershed Management Department is under a federal court order to address sanitary sewer overflows that should lower fecal matter in the water.