Tag Archives: release channel

Ashokan release adjustment

NYCDEP announced another increase in flow from 300 MGD (557 cfs) to 450 MGD (696 cfs) in a series of steps today (April 19, 2024) in accordance with the Interim Release Protocol (IRP).  The Ashokan spill and release combined will be maintained below 1000 MGD (1547 cfs).

As of April 19th, the Ashokan Reservoir storage is at 100.8 %, today’s CSSO is 97.7 %, the turbidity of the release is 5.0 NTU, and the Catskill Aqueduct is online diverting 310 MGD for water supply.

Ashokan release increased

Today, April 18th, NYCDEP announced an increase in release flow from 200 MGD (309 cfs) to 300 MGD (557 cfs) in three steps in accordance with the Interim Release Protocol(IRP).  The Ashokan spill and release combined will be maintained below 1000 MGD (1547 cfs).

Ashokan Reservoir storage is currently at 101.0 %. Today’s Conditional Seasonal Storage Objective (CSSO) is 97.4%. The turbidity of the release is 5.4 NTU. The Catskill Aqueduct is online diverting 310 MGD for water supply. 

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 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 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 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 releases adjusted

This morning the Ashokan Release Channel flow was increased from 300 MGD (464 cfs) to 450 MGD (696 cfs) to help reach the seasonal storage objective and to maintain a combined spill and release flow less than 1000MGD. The turbidity of water in the release channel is 14.9 NTU.

Ashokan Reservoir storage is 101% today. The reservoir started spilling on Sunday and is forecast to continue spilling through Saturday. The Catskill Aqueduct is online diverting 175 MGD for water supply.

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.

Release channel ready for shut down in response to rainfall

NYCDEP said it is prepared to shut down the release channel when the Lower Esopus water level rises. The Interim Release Protocol (IRP) stipulates shut down of release channel when creek level is within 1 foot of the “Action Stage” (18′) and is forecasted to reach “Action Stage”, as predicted on the National Weather Service forecast for Mt Marion stream gauge.

The Mount Marion forecast from the National Weather Service predicts the river stage to reach action level overnight Tuesday and peak near 19.9 feet by noon on Wednesday, January 10th.

The Ashokan Release Channel is continuing to operate at its maximum rate of 600 MGD (928 cfs) today and has been operating at this rate since December 22. Ashokan Reservoir storage peaked on December 22 at 99.4% and has been on the decline since. Ashokan Reservoir storage is currently at 93.9%, and the turbidity of the water in the release channel is 15.9 NTU. The Catskill Aqueduct is online and diverting 550 MGD for water supply. The release channel is prepared to shut down when water level reached 17 ft at Mt Marion stream gauge.

For the latest information see the Mt Marion stream gauge.