North Park Lake Workers Dig in Deep
By Bill Vidonic
Thursday, June 17, 2010
For nearly 80 years, North Park Lake was considered the centerpiece of the Allegheny County park, its serene waters welcoming boaters and anglers.
These days, it’s anything but welcoming, essentially little more than a muddy hole as it undergoes a $16 million transformation.
Within a year, if all goes according to plan, the lake will be deeper, bigger and once again host nature lovers from across the region.
“We had some little setbacks in the winter, but we’re making some good progress now,” said Craig Carney, project manager for the U.S. Army Corps of Engineers. “We’re still shooting for (finishing) next spring.”
Within the next couple of weeks, workers will begin scooping sediment off the lake bed and into dump trucks. Those trucks will be making 80 to 100 trips a day, Carney said, to an old fly ash dump along Wildwood Road, near the Pie Traynor baseball field.
Carney said motorists, joggers and bicyclists should be aware that the trucks will be in the park.
In all, the corps expects to remove more than 315,000 cubic yards of sediment from the lake.
Stormwater runoff has been dumping sediment into the lake for decades, according to the corps, along with stream bank erosion from portions of Pine Creek and North Fork creek. That shrunk the 75-acre lake to about 60 acres, and cut the depth of the water by more than half in many areas. Some areas of the lake turned into wetlands, and those areas will be protected.
Without the restoration work, Carney said, the lake — albeit in several decades — would degrade entirely into wetlands.
Work to divert North Fork from the upper portion of the lake was completed last week. Pine Creek’s diversion, on the lower portion of the lake, is continuing.
Carney said draining the lake didn’t go as smoothly as first hoped. The lake was drained in September and October, but heavy rains hit in November. Debris that collected at the lake’s gatehouse caused problems in draining the additional water, and that wasn’t fixed until March.
Since then, Carney said, drainage has gone relatively smoothly. Since the beginning of June, nearly 4 inches of rain has fallen. After each storm, workers are able to drain the water within a day or so.
“It’s been a typical spring,” Carney said. “We had a pretty dry late April and early May.”
History: The once-75-acre lake was created in the 1920s. It is located in Hampton, McCandless and Pine.
Project: Sediment had filled the lake, decreasing the lake’s depth and causing problems for boaters and anglers. The lake was drained beginning Sept. 8. Workers will remove at least 315,000 cubic yards of sediment. Once done, the lake will be restored to its original depth of up to 24 feet. North Fork and Pine Creek are being diverted on the northern and southern ends of the lake to drain the lake and allow workers to scoop up the sediment.
Other work: Improvements will be made to help mitigate downstream flooding. Coir logs, composed of coconut fiber, will be laid along the shoreline to prevent further erosion and sediment buildup. Invasive plants are being removed from the lakebed, which will be lined with gravel to encourage fish spawning. In October, 75 percent of North Park Lake fish, including blue gill, crappie, bass, sunfish and catfish, were relocated upstream to Marshall Lake and Deer Lakes Park.
Cost: $16 million. The federal government has contributed $5 million, and the state $400,000. Allegheny County is paying the remainder.
Source: U.S. Army Corps of Engineers