New York Codes, Rules and Regulations › Title 21 - Miscellaneous › Chapter XVIII - Delaware River Basin Commission › Subchapter E - Water Code › Part 890 - Conservation, Development And Utilization Of Delaware River Basin Water Resources › Allocation of Water Resources › Section 890.11 - Coordinated operation of lower basin and hydroelectric reservoirs during a basinwide drought

Current through Register Vol. 46, No. 28, July 10, 2024
During "drought" conditions as defined in Figure 1
						(section 890.9 of this Part), the Francis
						E. Walter, Prompton, Beltzville, Blue Marsh, Nockamixon, Lake Wallenpaupack and
						Mongaup hydroelectric reservoirs, will be utilized to complement the drought
						management operations of the New York City reservoirs. The priority of lower
						basin reservoir use to meet Trenton flow objectives is set forth in Table 1 of
						this section.
TABLE 1
PRIORITY OF USE FOR EXISTING
LOWER BASIN RESERVOIRS DURING DROUGHT
Operation to
								  Meet
Remaining
cfs-days
Priority
Trenton
								  Objective
Storage (%) bg
Used
1
Prompton*/**
2
F.E. Walter**
3
Beltzville to Elev. 615
73.7/9.89
5,475
3
Blue Marsh to Elev.
								  283***
68.9/5.13
3,595
4
Nockamixon to Elev. 385
68.7/9.00
6,364
5
Beltzville to Elev. 590
38.0/5.10
7,411
6
Blue Marsh to Elev. 273
36.8/2.74
3,700
7
Beltzville to Elev. 537
3.4/0.45
7,198
7
Blue Marsh to Elev.
								  261****
13.0/0.97
2,735
8
Nockamixon to Elev. 325.5
1.0/0.13
13,745
* Subject to reconstruction of temporary control gate
						(Depending on final negotiations with the Corps of Engineers).
** Would first require filling of temporary storage, so
						would not likely be available during the first year of a drought (use subject
						to final negotiations with the Corps of Engineers).
*** Blue Marsh Reservoir augments flow of the Schuylkill
						River and the Delaware River downstream of the Trenton gage at Philadelphia;
						however, for estuarine salinity control, flow augmentation in the Schuylkill
						River has roughly the same effect as an equal augmentation in the Delaware
						River at Trenton.
**** Sufficient storage would be retained to supply the
						needs of the Western Berks Water Authority.
Lake Wallenpaupack and the Mongaup reservoirs would be
						called upon to provide releases to assist in meeting the Montague flow
						objective in the summer and fall periods whenever reservoir releases would have
						to be directed by the River Master. These releases would be independent of
						lower basin release requirements needed to maintain flows at Trenton. After
						issuance of a Conservation Order by the commission, the power companies, as
						agreed upon, shall make power generation releases from storage only in
						accordance with commission direction. For Lake Wallenpaupack, the schedule is
						set forth in Table 2 of this section. While the Lake Wallenpaupack schedule is
						designed to meet drought management requirements, the lake levels have been
						established to preserve the recreation value of the lake during the summer
						months.
TABLE 2
LAKE WALLENPAUPACK ELEVATION SCHEDULE
DURING DROUGHT CONDITIONS
Month (1st Day)
Elevation (ft.)
Daily Average*
								  Discharge (cfs/24 hr.)**
June
1187.0
308
July
1185.0
297
August
1182.0
232
September
1179.0
247
October
1176.0
254
November
1173.0
282
December
1170.0
25
January
1171.1
25
February
1172.2
25
March
1176.6
25
April
1180.0
25
May
1184.9
25
June
1187.0
308
* Based on 1960's drought of record inflows.
** Daily release volume may be provided during "on peak"
						power periods.
For the Mongaup reservoirs, a drought operation rule
						curve will be followed. The rule curve will be based on maximum available
						storage of 15.38 billion gallons for the total system and will provide for
						refilling the system during the worst hydrologic year of record and for
						maintaining a minimum release. Daily average discharge for the period
						June-November inclusive generally will be on the order of 100-150 cfs/24-hours
						and for the period December-May inclusive generally will be on the order of
						20-30 cfs/24-hours. Temporary storage in Prompton reservoir would be used to
						help meet the Trenton objective; however, depending on upper and lower basin
						conditions, Prompton releases could also be used for a Montague objective if
						there was a critical need to conserve storage in the New York City Delaware
						Basin reservoirs and the combined storage in the Beltzville and Blue Marsh
						reservoirs was above 70% of capacity.
Francis E. Walter reservoir will be called upon to meet
						the Trenton flow objective only after any storage in Prompton is depleted. It
						is understood, however, that until this dam is modified to retain water supply
						storage, its function is flood control. It will not likely be available for
						flow maintenance during the first year of a drought if such drought is declared
						subsequent to June 1, or the end of the heavy spring runoff period. Water could
						be stored temporarily in flood control storage upon issuance of requests for
						storage and releases after issuance of a conservation order by the commission.
						In the event of a threatening major storm, temporarily stored water may have to
						be released in order to restore the necessary flood protection capacity of the
						dam. Water may also have to be released in order to draw down to the winter
						drought pool level at elevation 1,370 (see Table 3 of this section). If
						releases to meet winter drought pool requirements or to prepare for a storm
						occur when releases are not required for the Trenton flow objective, then the
						Montague requirement would be adjusted in order to save equivalent water in the
						New York City Delaware Basin reservoirs. In so doing, the storage saved in the
						New York City reservoirs would be available for use later should the drought
						persist, or be available, if conditions improve, to return to a normal
						condition at an earlier date, at which time restrictions could be
						lifted.
TABLE 3
TEMPORARY EMERGENCY WATER SUPPLY STORAGE AT F.E.
						WALTER RESERVOIR (PURSUANT TO DROUGHT DECLARATION)
F.E. Walter
								  Reservoir
Usable storage 11.30 bg
									 between elevations 1300
(DA 288 sq. mi.)
to 1392. Inactive storage
									 below elevation
1300-0.58 bg (1793
									 ac-ft)
Storage
Elevation (ft./s.l.d.)
Surface Area (acres)
(acre-ft.)
(bg)
(inches runoff)
Drought/
Summer Pool*
1392
824
36,458
11.88
2.37
Drought/
Winter Pool**
1370
587
20,831
6.79
1.36
Normal Pool
1300
80
1,793
0.58
0.12
1245
0
0
0
0
* Drought summer pool = 11.30 billion gallons of
						temporary water supply storage (32% of flood control storage).
** Drought winter pool = 6.21 billion gallons of
						temporary water supply storage (18% of flood control storage).
While it is clearly understood that the water supply
						storage at Beltzville and Blue Marsh reservoirs is to be used for water supply
						and to control salinity intrusion into the Delaware estuary during low flow
						periods, it is also recognized that extensive recreational development is
						established on these lakes, which should be protected to the extend possible.
						Accordingly, the operation plans for both of these reservoirs, as well as
						Nockamixon, in drought emergencies have recognized these multiple uses, with
						water supply having precedence.
After Francis E. Walter, then Beltzville, Blue Marsh, and
						Nockamixon reservoirs are used in that order down to the elevations indicated
						in Table 1 of this section for priorities 3 and 4, at which elevations
						recreation will become affected. Recreation will then be eliminated at
						Beltzville and Blue Marsh while retaining fish life, as those two reservoirs
						are drawn down to the elevations indicated as priorities 5 and 6. Finally, all
						remaining usable storage would be utilized as indicated by priorities 7 and
						8.
When only conservation releases are being made from the
						lower basin reservoirs, they will be modified according to Table 4 of this
						section, beginning with "drought warning" conditions, as defined by Figure 1 in
						section 890.9 of this Part. Drought
						conservation releases will terminate and return to normal at the same time as
						augmented conservation releases are restored at the New York City Delaware
						reservoirs.
TABLE 4
CONSERVATION RELEASES
Reservoir
Normal
									 Conservation Release (cfs)
Drought Warning
									 and Drought Conservation Releases (cfs)
F.E. Walter
50
43
Prompton
inflow-outflow
6
Beltzville
35
15
Blue Marsh
41 (50*)
21 (30*)
Nockamixon
11
7
* With Western Berks Water Authority release included. As
						the future needs of the Authority increase, the release will correspondingly
						increase.
Operation of the lower Basin reservoirs for drought
						management will continue unt\l termination of the drought emergency declaration
						by the Commission.
Footnotes
* Subject to reconstruction of temporary control gate
						(Depending on final negotiations with the Corps of Engineers).
** Would first require filling of temporary storage, so
						would not likely be available during the first year of a drought (use subject
						to final negotiations with the Corps of Engineers).
*** Blue Marsh Reservoir augments flow of the Schuylkill
						River and the Delaware River downstream of the Trenton gage at Philadelphia;
						however, for estuarine salinity control, flow augmentation in the Schuylkill
						River has roughly the same effect as an equal augmentation in the Delaware
						River at Trenton.
**** Sufficient storage would be retained to supply the
						needs of the Western Berks Water Authority.