The Virginia Soil and Water Conservation Board (VSWCB) is considering
a change to the Dam Safety Regulations, an alternative is being
considered that would require existing dam owners to upgrade
their dams to compensate for the additional potential hazards
created by subsequent downstream development.
A decision will be made at the next VSWCB meeting, which
will be held at 9:30 a.m. on Thursday, July 21, 2005, at the
Natural Resources Conservation Service’s Richmond
Office.
Currently, dams are classified by their size, as well as the
hazard potential that is expected during the life of the dam
based on current development conditions and zoning. Several
dam owners have expressed concerns with the costs associated
with updating dams in order to meet compliance when changes
in development conditions within the downstream inundation zone
have resulted in a change in the classification. The Ad Hoc
Dam Safety Study Committee was therefore established specifically
to review Section
40 (the Classes of Impounding Structures), Section 501
(Performance Standards Required for Impounding Structures),
and the Impounding Structures Table
1 of the Virginia
Impounding Structures Regulations.
The Committee met four times as a workgroup to develop several
alternatives to the current regulations. Ultimately, two alternatives
were recommended in a report titled, Report
of the Ad Hoc Dam Safety Committee to the Virginia Soil
and Water Conservation Board, dated April 30, 2005.
The first recommended alternative is to require both new and existing dams to
meet the same design and safety requirements. This alternative
would still require spillways to be designed for the full Probable
Maximum Flood (PMF) for the highest hazard dams and would require
some owners to have to upgrade their impounding structure.
The second recommended alternative is to provide alternative
standards for existing dams. This alternative would allow less
stringent design standards for dam owners who could justify/demonstrate
that their existing impounding structure would result in no
significant increase in downstream hazard. This would result
in decisions being made on a case-by-case basis, requiring more
time, coordination, negotiation and possibly field monitoring
to make such decisions.
In addition to recommending the alternatives, the report also
included in the conclusions that “...the Committee also recommends
that efforts be made to increase the degree to which dam safety
is recognized and considered by the public and local officials
as they make land use and development decisions. The Committee
also believes that land use zoning needs to be adopted or
adjusted to take the inundation area into account.”
The Ad Hoc Dam
Safety Committee presented their recommendations to the VSWCB
on Thursday, May 19, 2005. The Committee provided more support
for Alternative 2, but was specific in pointing out that both
alternatives would result in achieving the same level of protection
from potential hazards. After discussing both alternatives,
the VSWCB unanimously passed the following motion:
“...that the Virginia
Soil and Water Conservation Board accept the report of the
Ad Hoc Dam Safety Study Committee and direct the staff to
provide further information regarding Alternatives 1 and 2
at the July meeting.”
If you are concerned
about this issue, you should attend the Board's next meeting
and articulate your concerns.
For more information concerning this
topic, contact Mike
Marsala.
1Section 50 has been excerpted for easy reading in Table 1.
