Current through Register Vol. 48, No. 9, September 27, 2024
Anytime the flow at the point of the permitted withdrawal is
less than or equal to the minimum instream flow and taking into consideration
natural and artificial replenishment of the surface water and existing or
planned consumptive and nonconsumptive uses affected by the withdrawal
downstream, the permitted surface water withdrawer must implement applicable
portions of its water contingency plan and, excepting public water systems
addressed in Section
49-4-150(A)(6),
will discontinue facility consumptive water uses from the surface water source
such that continued withdrawals will result in no net decrease in flow below
the facility's discharge.
a. Each
permittee must prepare and maintain on site, available for inspection, an
operational and contingency plan to promote an adequate water supply from the
surface water during times when the actual flow of the surface water is less
than the minimum instream flow, plus any flow necessary to protect downstream
permitted and registered withdrawals, taking into account natural and
artificial replenishment of the surface water, for that particular surface
water segment. The existence of a plan is deemed to be an enforceable part of
the permit under which the permittee is withdrawing surface water and shall be
deemed to control a permitted surface water withdrawal in situations where the
actual flow of the surface water is less than the minimum instream flow for
that particular stream segment.
b.
For applicable new or expanding surface water withdrawers, the plan must
identify actions to be taken to address low flow conditions, including: water
conservation, use of supplemental water supplies, use of off-stream water
storage, operational changes, seasonal water flow fluctuation withdrawals, or
hydroelectric operations in controlled surface waters. For expansion of permits
initially issued under section D above, the requirements of this section only
apply to the permitted amount over and above the permitted quantity of the
initial permit.
c. Public water
systems must develop operational and contingency plans consistent with E.4.b.
above and implement their plan, applicable to their service territory,
commensurate with the drought level declared by the State Drought Response
Committee and in accordance with any drought response plan required by the
owner of a licensed impoundment that they use as a water source.
d. Non-public water withdrawers must develop
operational and contingency plans consistent with E.4.b. above and implement
them consistent with the requirements of this section and act in accordance
with any drought response plan required by the owner of a licensed impoundment
that they use as a water source.
e.
For surface water withdrawers with an operational and contingency plan
requiring one or more supplemental sources of water to be used for continued
facility operations during minimum instream flow conditions, the supplemental
water supply needed will be addressed as follows.
i. For a surface water withdrawer proposing
to use surface water as all or a portion of the supplemental water supply:
(A) Where only surface water will be used as
a supplemental supply, the volume of water required to be stored is set forth
in Section
49-4-150(A)(2)(c),
and the following used as an aid to such determinations.
(1) Using an appropriate USGS or Department
approved gaging station, historical flow at the withdrawal point will be
determined. Factors to be considered in determining an appropriate index
station include but are not limited to drainage area, flow characteristics,
physiographic province, period of record, and land use.
(2) Using the flow record at the appropriate
index station, a daily flow record for the longest period of record feasible
will be determined at the proposed withdrawal point. All years experiencing
periods of flow below the minimum instream flow for the months July through
November will be determined and evaluated, up to and including the drought of
record. For the purposes of this section, the drought of record will be
considered the July through November period, within the period of record,
having the largest number of days with flows equal to or less than the minimum
instream flow.
(3) Using the flow
records of July through November periods experiencing flows equal to or less
than the minimum instream flow, including but not limited to the drought of
record, the Department will determine a supplemental water volume for inclusion
in any permit to be issued for the withdrawal. The supplemental water volume is
not required to be any larger than the quantity that allows for facility
operations during twenty percent mean annual daily flow conditions, based upon
a review of historical low flow data and projected facility consumptive water
uses during low flow periods. Facility consumptive water uses means the amount
of water that is lost and not returned to the source waterbody during normal
operations.
(4) If an appropriate
index station with an appropriate period of record is not available, the
Department, in consultation with the applicant, will determine an appropriate
storage volume using the best information available. The USGS and/or SCDNR may
be consulted as needed.
(B) For a surface water withdrawer proposing
to utilize surface water in conjunction with other supplemental sources to
satisfy contingency plan requirements, the volume of supplemental supply needed
will be determined as in item E.4.e.i(A) above with due consideration given to
the volume of water to be supplied by sources other than surface water when
determining drought contingency pond size.
(C) A permitted surface water withdrawer
utilizing a drought contingency pond as all or some of its supplemental water
source may withdraw the entire volume of water from the pond during low flow
periods requiring supplemental water source usage. Water withdrawn from drought
contingency ponds is not subject to environmental and permitting restrictions
unless or until it is discharged to state waters. The Department will designate
drought contingency ponds, a type of supplemental water source, as part of an
approved operational and contingency plan.
(D) For withdrawals where the withdrawal
point is not located on a licensed or otherwise flow controlled impoundment, a
permitted surface water withdrawer may withdraw water from the permitted
surface withdrawal point in order to refill its supplemental water source, or
other drought contingency water supply vessels, anytime the river flow exceeds
the minimum instream flow, provided the total amount withdrawn for daily
operations and for refilling the supplemental water source or other drought
contingency water supply vessel does not cause the flow downstream of the
withdrawal point to go below the minimum instream flow plus any flow necessary
to protect downstream permitted and registered withdrawals.
(E) For withdrawals where the withdrawal
point is located on a licensed or otherwise flow controlled impoundment, the
permitted withdrawer may withdraw water to refill his supplemental water source
or other drought contingency water supply vessel anytime the total amount
withdrawn for daily operations and for refilling the supplemental water source
does not cause the reservoir water level to drop below its minimum water level
or to be unable to release the lowest minimum flow specified in the license for
the impoundment as issued by the appropriate government agency.
ii. For a surface water withdrawer
proposing to utilize groundwater obtained on its site as a supplemental source,
the applicant must document the availability of groundwater of sufficient
quantity to provide for the withdrawer's daily needs for a period of time at
least equal to the period of time the surface water will be unavailable as
determined in item E.4.e.i(A) above. Any permits or approvals required to
extract groundwater for use as a supplemental source must be obtained prior to
issuance of a surface water withdrawal permit.
iii. For a surface water withdrawer proposing
to utilize as their supplemental source water purchased from: another surface
water withdrawer; a permitted discharger; a supplier using groundwater as its
source; or other source approved by the Department, the withdrawer must
demonstrate via contract or other legally binding commitment the availability
of a sufficient quantity of water to provide for the withdrawer's daily needs
for a period of time at least equal to the period of time the surface water
will be unavailable as determined in item E.4.e.i(A) above.
iv. New surface water withdrawers are not
required to engineer the supplemental water source identified in their
contingency plan any larger than the quantity that allows for facility
operations during twenty percent mean annual daily flow conditions, based upon
a review of historical low flow data and projected facility consumptive water
uses during low flow periods.
v. A
new surface water withdrawer may not return to the withdrawal source when its
supplemental water source is exhausted unless the supplemental water source has
been engineered to meet the specifications of this section.
vi. If after all reasonable contingency plans
have been implemented, and the surface water withdrawer is within fifteen (15)
days of exhausting the usable water supply from its supplemental water source,
a new surface water withdrawer may give notice to the Department that he is
exhausting his supplemental water sources and that he intends to return to the
withdrawal source in amounts up to his permitted amount. Notification must be
made in writing as expeditiously as possible, to include electronic
communication, to the address provided in the permit. Upon receiving notice,
the Department must determine whether all or any portion of the withdrawal for
facility consumptive water uses will result in a significant negative impact to
an existing user or the environment if the permitted withdrawal is resumed. If
the Department does not make its determination within ten (10) days of receipt
of notice, the permittee may make withdrawals up to the permitted amount and do
so until notified by the Department whether all or any portion of the
withdrawal for facility consumptive water uses will result in a significant
negative impact to an existing user or the environment during this low flow
period. Upon notification by the Department, the permittee will cease
withdrawals for facility consumptive water uses that will result in any
significant negative impact.
f. The Department must consult with the SCDNR
to determine which, if any, existing stream gaging station should be utilized
to quantify the stream flow at the point of the proposed withdrawal. The
Department may also seek the input of the applicant in determining a suitable
means to measure or extrapolate the stream flow at the point of the proposed
withdrawal. If no existing stream gage is suitable for measuring or
extrapolating the flow at which the applicant's water withdrawal must be
reduced due to inadequate stream flow, the SCDNR will recommend the location of
a new stream gage.
g. The
Department must consult with the SCDNR to quantify the stream flow measured at
the specified measuring device that will require a reduction in the applicant's
water withdrawal because of inadequate stream flow at the point of
withdrawal.
