The North Fort Bend Water Authority (NFBWA) is a
regional water authority created by the 79TH Texas
Legislature, with the passage of Senate Bill 1798 in May
2005 and by establishing Chapter 8813 of the Special
District Local Laws Code.
A. The primary reason was to facilitate
compliance with the Fort Bend Subsidence District’s
groundwater reduction mandates by creating a viable
single entity to acquire, develop and deliver a long
term supply of potable surface water to water users
within the Authority’s boundaries. The mandates are
outlined in the Subsidence District’s 2003
Regulatory Plan, and are intended to wean the area
off its dependence on groundwater
in a phased reduction plan, to minimize the risk of
future subsidence, and to enable the aquifers that
serve the region to recharge.
In addition, Fort Bend County has monitored the
water supply issue since the late 1980’s through the
Fort Bend County Surface Water Supply Corporation.
The Corporation completed a detailed study in 2002
which concluded that rapid population growth in Fort
Bend County combined with the Subsidence District’s
groundwater reduction requirements will likely cause
water shortages in the County as early as 2014.
Fort Bend County is trying to avoid the problems
with subsidence and water supply that portions of
Galveston and Harris Counties have suffered.
A. Webster’s defines subsidence as “to sink, to
fall to the bottom; to settle.” Technically
speaking, it is the reduction or decline in
elevation of the land surface due to compressing the
many underlying layers of soil. While it
occurs slowly over long periods of time due to the
natural compaction of soils, subsidence can be
greatly accelerated by the withdrawal of groundwater
from underground aquifers. In the Gulf Coast region,
the withdrawal of oil and natural gas is also
credited with contributing to subsidence.
The fluids withdrawn from very shallow oil and
gas fields allowed the clay layers to compact
beneath the land surface. Approximately two feet of
subsidence resulted from early 20th century oil and
gas withdrawal. The growth of greater Houston since
the 1920’s demanded significant water supplies. The
aquifers beneath land surface yielded amazing
amounts of high quality water, and the area grew
substantially on the basis of an available — and
seemingly endless – source of groundwater. However,
since the original two feet of subsidence from oil
and gas withdrawal, the burgeoning population’s
thirst for groundwater caused as much as five times
more subsidence.
In the early 1970’s, groundwater pumpage was
approaching 450 million gallons per day (mgd).
Subsidence had resulted in elevation losses that
threatened entire subdivisions with complete
destruction from tidal flooding. With the water
demands of the mushrooming population and the
expanding petrochemical industry by the mid-1970’s,
at least 6 feet of subsidence had occurred along an
area between Baytown and Houston. The fate of the
Brownwood subdivision of Baytown affords a
particularly dramatic example of the dangers of
coastal subsidence.
Brownwood
was an upper income community of about 500
single-family houses constructed on wooded lots
along Galveston Bay beginning in 1938. The area was
originally 10 feet or less above sea level, but by
1978, more than 8 feet of subsidence had occurred.
In July of 1979, 12 inches of rain fell on the
subdivision and caused the flooding of 187 homes. In
1983, Hurricane Alicia struck a final blow, and all
homes in Brownwood were abandoned. Today, the area
is a swampy area best suited as home to waterfowl.
The Texas Legislature created the
Harris-Galveston Subsidence District in 1975, to
tackle the problem of subsidence. (The Fort Bend
Subsidence District was created in 1989.) The
District focused first on the coastal areas, which
were most at risk due to the lower elevations.
Cities and industries were largely cooperative and
from 1976 to 1985, groundwater pumpage was reduced
dramatically.
While groundwater reduction was producing
significant results in Galveston County and
southeastern Harris County, north and west Harris
County began to subside at increasing rates due to
the increased pumpage to serve the population
growth.
Groundwater pumpage had increased significantly
through the late 80’s and subsidence rates in
northwest Harris County were beginning to equal the
all time historic high rates from eastern Harris
County — at one-tenth to one-quarter a foot per
year.
The Jersey Village area suffered subsidence of 5
feet or more. On two successive years, extreme
rainfalls caused major flooding throughout the
subdivision…to the extent that some twice-flooded
homes were purchased by FEMA.
In addition to Subsidence, the water levels in
the water wells have declined significantly,
endangering the supply of potable water. The US
Geological Survey monitors what is happening to the
water in the
aquifers
that supply the groundwater wells. The Jersey
Village area, for example, has experienced a water
level decline of up to 260 feet. The Champions/1960
and the F.M. 529/State Highway 6 areas have
experienced declines which have affected both the
quantity and quality of their water supplies.
Over the next 50 years, the greater Houston area
is expected to more than double — essentially adding
the current population of the City of Los Angeles to
what is already the 4th largest city in the USA. If
the increasing population were to rely on
groundwater to quench its thirst, another 5 feet of
subsidence would result in northwest Harris County
by 2030.
The Subsidence District has demonstrated that
reducing groundwater demand does in fact help halt
subsidence. In some areas where reduction plans have
been in place over the past several decades, the
aquifers have recharged as well. Also critical,
however – in both the short- and long-term – is the
teaching and implementation of water conservation
throughout our communities, neighborhoods,
businesses, and households…all the way down to the
youngest family members.
