July
31 monsoon a ‘100‑year storm’
Town
engineer confirms total rainfall crossed threshold
by
Brian DiTullio
CAREFREE
– The much talked about possibility of a 100‑year
flood became a reality in Carefree on July 31, say town
officials.
Town
engineer Erich Korsten said Carefree’s criteria for a
100‑year storm is 2.41 inches of
rainfall in a one‑hour period. On July 31, between
2.44 and 2.88 inches of water fell in an hour‑and‑a‑half,
as registered by the town’s two monitors.
“This
qualifies as a 100‑year storm,” Korsten informed
town council at its Aug. 7 regular meeting.
One
of the monitors is located near the intersection of Stagecoach
Pass and Pima Road, the other near the Carefree Ranch.
“It
meets the requirement not only for rain depth, but also
for rain intensity” Korsten said.
During
call to the public, several residents complained that
development has altered or increased water flows in certain
parts of town, particularly south of the Cave Creek Road/Tranquil
Trail intersection.
“There’s
so much water coming down, the drainage can’t handle it,”
Randy Pagel said.
Korsten,
however, pointed out to the audience that the July 31
downpour was the 100‑year storm for which all town
roads and drainage plans were engineered and that everything
performed exactly as planned.
“No
homes have been flooded that I have been made aware of,”
the town engineer said, adding inspections showed 21 locations
around Carefree suffered some kind of storm damage, mainly
sediment on the roadways or some erosion of land. “It
wasn’t more development; it was more water,” he stated.
Korsten
also explained the rain wasn’t a slow, steady rain but,
instead, developed fast with an intense, sustained flow.
“Everything you looked at was bad and created a lot of
runoff.”
Some
residents pointed to the Dream Street bridge as having
narrowed the wash, increasing water flow through that
area due to its construction, but Korsten said the bridge
was engineered for the wash which already was narrow at
that location.
“We
did not encroach on that wash at all (with its construction),”
stated Korsten, noting the bridge performed well under
the 100‑year storm conditions and no water spilled
over the street.
Vice
Mayor Lloyd Meyer said there was “no way to compare this
(storm) to anything else” because of the amount of water
it dumped in such a short time span.
Councilman
Bob Coady asked who bears responsibility for maintaining
the washes, to which Korsten replied that individual homeowners
are responsible for any part of a wash going through their
property.
Carefree
Water Company manager Stan Francom said Long Rifle Road
lost some pavement in the storm and that it took his crews
about five days to clean everything up. It normally takes
two days to clean up after a big storm, he added.
Asked
about costs, he reported the backfill used was obtained
at no charge. Francom also noted that storm cleanup is
figured into the yearly budget.
