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Another rain reprieve
for area water
Raleigh,
which had been lurching from shower to shower in an attempt to avoid imposing
stricter water conservation measures, won a huge reprieve from Sunday’s soaking
rain.
Falls
Lake had risen more than a foot by Wednesday morning, standing at 243.2 feet
above mean sea level. “The lake reached a new
all-time record low level of 241.52 feet MSL on Christmas Day,” Dale Crisp, the
director for Raleigh’s Public Utilities Department, wrote in his weekly update
on Monday. The lake is expected to continue to rise this week.
The
rain, 1.8 inches measured at the airport, gives the city and the water systems
it owns – Wake Forest, Rolesville, Garner, Knightdale, Wendell and Zebulon – at
least 112 days of water. That number had fallen to 96 days last Friday.
The
city was poised to implement Stage 2 restrictions when the available supply
dipped to 90 days. Those restrictions would have caused a screeching halt to
construction because they would have banned flushing and sterilizing of new
water connections. Also, Stage 2 restrictions ban power-washing, hand-watering
of lawns and gardens and washing vehicles at home.
Sunday’s
rain may also change the drought designation for the area. It has been
designated as being in an exceptional drought, the most extreme category. The
weekly updates are released on Thursdays.
During
next week’s meeting of all the Falls Lake stakeholders, the discussions will
include ones about accessing the sedimentation pool in Falls and the
often-raised question about dredging out some of the dry areas in Falls.
Dale
Pendleton, owner of The Raleigh Boat Exchange in Durham, recently asked those
stakeholders and officials: “What is the quality of the water that is delivered
to the public water supply? I say this because the wastewater treatment plants
are still discharge into the lake and there is significantly less water in the
lake to dilute their output”
George
Rogers, who was the supervisor of Wake Forest’s water and sewer systems before
merger and is now the environmental coordinator for Raleigh’s utilities, sent
an answer in an e-mail to Crisp and copied widely.
“The raw water quality
in Falls Lake is largely dependent on rainfall events and varies considerably
from the upper reaches of Falls Lake to the intake near the water treatment
plant. The water quality upstream is poor due to the drought but the water
quality at the intake is better than usual this year for the same reason. Large
rainfall events have a greater impact on raw water quality at the intake than
drought because of the nutrients and sediments washed into the lake during
heavy rains.
The upper portion of
Falls Lake sees long-term impairment in water quality due to turbidity
(sediments) and the entire lake sees higher chlorophyll-a (nutrient response)
than NC water quality standards. There will be a NC Division Water Quality
report on Falls Lake soon. The DWQ is preparing a model that will be used to
determine loading rates and limits on discharges to Falls. There will
also be additional rules proposed to control stormwater pollution.
“Historically, metals
have not been pollutants of concern in the Falls Lake watershed.
“Overall, the raw water
quality in the Falls Lake watershed is excellent.”
Vicki Westbrook with the City of
Durham also answered Pendleton’s question, giving the pounds of phosphorus and
nitrogen discharged by the two Durham wastewater treatment plants, but without
a reference framework the numbers do not give a picture laypeople can
understand.
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