ITEM: INFORMATIONAL ITEMS/STAFF REPORTS
13. CARMEL
RIVER FISHERY REPORT
Meeting
Date: November 17, 2003 Budgeted: N/A
Program/Line
Item No.: Aquatic Staff
Staff Contact: Dave Dettman/ Resources Fisheries, 2.4
Beverly Chaney Cost Estimate: N/A
General Counsel Approval: N/A
Committee Recommendation: N/A
CEQA Compliance:
N/A
AQUATIC HABITAT AND FLOW CONDITIONS: During October 2003, Carmel River streamflow conditions were critical or lethal for rearing juvenile steelhead in the lower river and good for rearing fish upstream of Robinson Canyon. In October, mean daily streamflow recorded at the District’s Carmel River Sleepy Hollow Weir gaging station averaged 7.8 cubic feet-per-second (cfs) and ranged from 6.8 to 9.6 cfs.
In October
2003, 0.34 inches of rainfall was recorded by Cal-Am at San Clemente Dam
(SCD). The long-term October average at
this site is 0.71 inches.
The
Carmel River Lagoon has been closed since July 2, 2003. Lagoon water quality was fair to good for
steelhead during October. Following a
seasonal minimum in August, water depth began to recover early in October and
now is ranging below five feet (See chart below). Streamflow at the District’s Highway One Bridge declined to zero
on July 27 and the riverfront receded upstream, ultimately stabilizing at point
approximately 0.5 mile downstream of Schulte Road Bridge in early
September. During early October, the
riverfront advanced downstream approximately 3/8 mile in response to lower
Cal-Am production, but then retreated by an equal distance as water demand
peaked in the last week of October.
Carmel Lagoon Water Level October 2003
SUMMER STEELHEAD RESCUES: Staff started the 2003 summer steelhead rescues on June 30, 2003 as flows neared 10 cfs at the Highway 1 bridge. By September 5, 2003 a total of 55,287 fish had been rescued including 39,553 by MPWMD staff and 15,287 by volunteers from the Carmel River Steelhead Association (CRSA) (See inset chart below). The combined rescue totals for MPWMD and CRSA set a ten-year record for the number of fish rescued, exceeding the previous record of 38,995 in 2001 by approximately 16,000 fish. This year’s record numbers are probably a reflection of improved substrate conditions, increased numbers of returning adult steelhead due to past rescues of juvenile steelhead in this reach, and high reproductive success due to low, but adequate flows for spawning, embryo incubation, and fry emergence.
SLEEPY HOLLOW STEELHEAD REARING FACILITY: Currently, the Facility is in production mode, with all pumps functioning normally and the cooling tower running. By September 5, 2003, when fish rescues effectively ended, staff had stocked 28,327 fish at the Facility, or approximately one-half of the total number rescued from the lower river. As of October 31, a total of 21,151 fish had survived including 20,390 fish on hand, 353 fish that were released, and 408 fish the voluntarily escaped to the river. To date, overall survival is estimated at 75% (21,151/28,327).
Turbidity Levels:
Throughout this year’s rearing season, the turbidity of water at the
intake to the Facility has been elevated due to continuing operations at San
Clemente Dam, where Cal-Am has been required to lower the water surface
elevation for the Interim Drawdown Project (IDP). The purpose of the IDP is to reduce the safety risk to downstream
lives, following a seismic failure of San Clemente Dam. One environmental consequence of the IDP has
been elevated turbidity of water released through the dam. During the IDP,
turbidity levels in the reservoir have ranged from approximately 7 to 28
Nephelometric Units (NTUs), representing a 10- to 100-fold increase compared to
typical pre-project levels (See inset chart below).[1] Currently, turbidity is ranging from 15-19
NTU’s, but is expected to spike again as inflows increase due to storms. At the Facility intake, levels are somewhat
lower, but still significantly above pre-project levels and in a range that can
affect fish health. While the increased
turbidity has not apparently caused direct mortality to fish in the Facility,
levels in the 15+ ranges appear to interfere with feeding, especially in
rearing tanks, where particles tend to remain in suspension. In the upper end of the rearing channel,
turbidity is equal to or slightly lower than river levels, but some of the
suspended material settles out in the channel.
Early Release of Fish from Facility: Based on discussions with Cal-Am, CDFG, and NOAA-Fisheries, District staff is beginning to release fish from the Facility. This is earlier than in past years and addresses the risk that sediment from San Clemente Dam may overwhelm the intake system at the Facility within the near future. Recently, the Department of Water Resources, Division of Safety of Dams changed their order for planned operation of the reservoir during the winter. At the present time, it appears that Cal-Am will be required to hold the water surface elevation at 514 feet year round, whenever feasible. This means that sediment may begin moving out of the reservoir area within the next six months to two years. While there is some small risk associated with releasing the fish earlier, before the lower river has advanced to the lagoon, staff believes the risk of holding fish while increased sediment is mobilized during early storm events is far greater.
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11/3/2003 3:51:57 PM