Autumn on Lake Audobon

Autumn on Lake Audobon
Autumn on Lake Audubon, Photo by Alison Kamat

Friday, October 16, 2015

FCPS ignores current stormwater management standards and downstream damage in South Lakes High School expansion proposal.

In their report on the much-needed proposed 40,000 SF addition to South Lakes High School (SLHS), the County planning staff note that Fairfax County Public Schools (FCPS) does not plan to meet current stormwater management standards approved just a year ago.  Instead, they obtained a waiver from the state Department of Environmental Quality (DEQ) to use earlier, less stringent requirements.  Here is what the staff report says:
Staff notes the applicant has received approval of a general permit through the Virginia Department of Environmental Quality (DEQ), which allows for the applicant’s proposal to be grandfathered under the old stormwater management requirements prior to the Board’s adoption of the new stormwater ordinance in 2014.
By using this waiver, FCPS will contribute even further to the erosion, silting, and--most recently--raw sewage release into Lake Audubon as a result of the massive stormwater flows from SLHS property through a ravine south of South Lakes Drive.  The stormwater releases have cut through the natural ravine surface to a depth of more than twelve feet near the mouth of the creek, forcing the County's public works department (DPWES) to rebuild the bottom and shoreline with very large rip-rap (large boulders to protect the shoreline).  DPWES has also had to add rip-rap at two places farther upstream where its sewer line is also exposed, but the torrents from SLHS have eroded the base underneath those simple fixes so the sewer line is hanging several feet above the ravine's base.  Three residential laterals connected to the sewer line are also exposed and suspended and are at risk of breaking (although two neighbors have reinforced their laterals by double-wrapping them with high-strength pipes).

The erosion and silting problem has gotten worse with every addition to SLHS in its near-40 year history.  The addition to the high school a decade ago included the addition of more than 100 asphalt parking spaces on the east side of the school, and the larger impermeable surface added to the flow into the basin to the east, through the tunnel under South Lakes Drive, and plunging down the ravine to Lake Audubon.  This summer, FCPS tried to remedy the flooding in the townhouse development on the other side of the basin caused by the additional runoff from its parking lot.  In so doing, it accelerated the flow through South Lakes Drive tunnel, turning the downstream side of the tunnel into a spigot throwing large volumes of stormwater at high speeds down the steep incline to Lake Audubon (30' drop in 1,000').  One consequence, in a recent storm, the County sewer line that runs along and across the ravine broke, spewing raw sewage into the stream and the lake.

It was only at that point and with pressure from RA leaders that Supervisor Hudgins agreed to begin a process to see how the stormwater problem might be remediated.  The first step in that process was a meeting with the community, specifically the two neighborhoods--Cedar Cove and Wakerobin--directly affected by the eroding stream.  It was no surprise that no one from FCPS attended the meeting.  At that meeting, held on Tuesday evening at RA headquarters, DPWES personnel laid out the process through which such a remediation project must go.  Suffice it to say, it will be at least three years and maybe five before the stream below South Lakes Drive will be repaired--and that's if the project makes the budget cut.

Community members highlighted that the problem originates with the repeatedly inadequate effort of FCPS to control the stormwater flow on its property across the street, and that the problem won't be solved until FCPS stops the torrential flows, an outcome impossible with its current plan for the SLHS addition.  The community also highlighted that this problem has been a continuing for years and was brought to Supervisor Hudgins attention in a creekside meeting at least eleven years ago.  It is time to set a side the normal business process and accelerate the remediation effort starting with completing the assessment and design process in time to seek full funding for construction in the next fiscal year.  That was left for further consideration.

RA leaders promised to follow up on the community meeting with Supervisor Hudgins by the end of the month.

Separately, Terry Maynard, among the Wakerobin homeowners affected by the creek's deterioration, sent a letter to FCPS Board Chairman and Hunter Mill District Representative Pat Hynes detailing the problem, FCPS' continuing refusal to address it in any meaningful way, and calling on her and FCPS to at least meet the requirements of the current County stormwater management ordinance and possibly even take leadership in remediating the stream.  No response has been received yet.

Below are two short videos showing the water flows a day after a major recent downpour.  One shows the repaired sewer pipe (light blue wrapping) in the midst of the flow.  The other shows the water tumbling from the South Lakes tunnel down the stream below. 


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