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Ashokan Release Channel Operations, News

Ashokan releases fluctuating during valve repairs

NYCDEP announced that perform critical and necessary repairs on the flow control valves for the Ashokan Release Channel from July 22 through July 31. During this time, flows in the release channel and points downstream will increase and fluctuate for brief intervals. The maximum release flows anticipated will be 600 MGD (930 cfs), and the minimum release flow will be maintained at 15 MGD (23 cfs) during the entire period. NYSDEC has approved the varying flow conditions and use of an alternate release point. Release Channel operations will otherwise continue in accordance with the Interim Release Protocol. 

Anglers and recreational users are advised to check local USGS gaging stations at Lomontville or Mt Marion and be aware of rapidly changing conditions. Stream level changes of 2.0 to 2.5 feet at both Lomontville and Mount Marion are expected from current conditions. The changes propagate along the creek from upstream to downstream and approximately 18 to 30 hours to travel from the Ashokan Reservoir to Mount Marion.  

Ashokan Release Channel Operations, Uncategorized

Ashokan release returns to minimum flow

NYCDEP announced additional decreases to the flow in the Ashokan Release Channel today from 200 MGD (309 cfs) to 10 MGD (15 cfs). The decrease started at 8:00 AM today (April 25th) in a series of steps until 2:00 PM.

Ashokan Reservoir storage is at 98.7 %. The CSSO for April 25th is 98.9%. Turbidity of the water in the release channel is 3.9 NTU.

Note: on May 1, the community release minimum shifts to 10 MGD and from May 1-June 30 no CSSO is in effect in accordance with the Intermim Release Protocol (IRP). NYCDEP monitor conditions and makes adjustments to releases pursuant to the IRP.

Ashokan Release Channel Operations

Ashokan release decreased

NYCDEP announced that it is decreasing the flow in the Ashokan Release Channel today (April 24) from 450 MGD (696 cfs) to 200 MGD (309 cfs). Additional decreases are expected as Ashokan storage approaches the Conditional Seasonal Storage Objective (CSSO).

Ashokan Reservoir storage combined is at 99.0% today, with the west basin at 96.6% and east basin at 100.3% with a slight spill at a rate of 51 MGD (79 cfs). The CSSO for April 24 is 98.7%, and the 30-year historical average is 100%. Turbidity of the water in the release channel is 4.1 NTU.

NYC DEP will continue to monitor conditions and make additional adjustments pursuant to the Interim Release Protocol (IRP.) Note: on May 1 the community release minimum shifts to 10 MGD, and from May 1-June 30 no CSSO is in effect in accordance with the IRP.  

Ashokan Release Channel Operations

Ashokan Release Channel Reactivated, April 17, 2024

NYCDEP announced that the Ashokan Release Channel was reactivated today and flow will be gradually increased to 200 MGD (309 cfs).  The combined flow of the Ashokan spillway and release channel will be maintained below 1000 MGD (1547 cfs) as stipulated by the Interim Release Protocol (IRP).

Ashokan Reservoir storage is currently at 101.2 %. Today’s Conditinal Seasonal Storage Objective (CSSO) is 97.2 %. The turbidity of the release is 4.0 NTU. The Catskill Aqueduct is online diverting 310 MGD for water supply. NYCDEP will continue to monitor conditions and make additional adjustments pursuant to the IRP. 

Ashokan Release Channel Operations

Ashokan Release Channel Shutdown

According to NYCDEP, the Ashokan Release Channel was shutdown at around mid-day on Friday, April 12th in accordance with the Interim Release Protocol (IRP) in response to rising creek levels and the National Weather Service forecast for the Mt Marion stream gauge .

NYCDEP is monitoring the stream gauge. Also, the Ashokan Reservoir is forecasted to spill beginning tomorrow morning and continuing through the weekend. The release channel will be re-activated once the streamflow and spill stabilizes. According to the IRP, operations can commence once Mt Marion falls below action stage so long as the combined spill and release flow rate remains below the 1000 MGD.   

As of April 12th, the Ashokan Reservoir storage was at 99.2% and the Combined Seasonal Storage Objective was at 96.0%. The turbidity of the release at shutdown was 2.2 NTU. The Catskill Aqueduct remains online diverting 400 MGD for water supply. 

Ashokan Release Channel Operations

Ashokan Release Adjustments

NYCDEP reported closure of the Ashokan Release Channel for a 10-hour period on Sunday, March 24th from around midnight to 10:00 AM, prompted by the Esopus Creek at Mt. Marion stream gage exceeding the “Action Stage” of 18ft. Afterwards, the Ashokan Release Channel was gradually reactivated to a flow of 440 MGD (681 CFS). As of Monday, March 25th, the release turbidity is 2.7 NTU, Ashokan Reservoir storage is at 98.3%, above the Conditional Seasonal Storage Objective (CSSO) of 92.3%. The Catskill Aqueduct is online and diverting 375 MGD (580 CFS) for water supply. NYCDEP will continue to monitor conditions and make additional release adjustments pursuant to the Interim Release Protocol (IRP).

Ashokan Release Channel Operations

Ashokan Release Adjustments

The Ashokan Release Channel was shut down over the weekend in response to the rising Esopus Creek water level at the Mt Marion gauge. With the Mt Marion dropping below Action Stage, the Ashokan Release Channel was reactivated on Monday, March 11th, increasing from 0 MGD to 420 MGD in a series of steps. NYSDEP will continue to monitor conditions and make additional adjustments pursuant to the Interim Release Protocol.

As of March 11, the current release turbidity is 5.3 NTU, Ashokan Reservoir storage is 97.7%, and the Catskill Aqueduct is online diverting 310 MGD for water supply.

Ashokan Release Channel Operations

Release channel reactivated, reservoir spilling

The Ashokan Release Channel was reactivated after the stream level at Mount Marion dropped below Action Stage. The current release flow is 300MGD and turbidity is 17.5 ntu.

Ashokan Reservoir storage reached 100% and starting spilling overnight Sunday, January 14th. DEP will monitor the spill and release flow rates to ensure that combined total is less than 1000MGD (1550 cfs), adjusting the release rate accordingly. The Catskill Aqueduct is online diverting 125 MGD for water supply.

DEP will continue to monitor conditions and make additional adjustments pursuant to the IRP.

Ashokan Release Channel Operations

Ashokan releases ramping up today

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NYCDEP Bureau of Water Supply will be increasing the release of water from the Ashokan Reservoir through the Release Channel Saturday December 1st. This increased release has been coordinated with NYSDEC and will not exceed 600 MGD and will last for 3 weeks. The purpose of the increased diversion is to temporarily stop the Schoharie Reservoir from spilling in order to complete the construction of at least one of the two new temporary siphons at Gilboa Dam.

The current release channel turbidity is 9.20 ntu. Releases are scheduled to ramp up in 40 MDG increments hourly, reaching 530 MGD by 4:30PM today.