Category Archives: Ashokan Release Channel Operations

Release channel re-activated

The Ashokan Release Channel has been re-activated after a shutdown during Winter Storm Finn. Now that Mt. Marion stream gauge has dropped below the action stage of 18 ft,  NYCDEP will resume releases, increasing from 0 MGD to 600 MGD (928 cfs) in a series of steps that started today, January 11, at approximately 8 AM and will continue throughout the day concluding on or about 7:00 PM.

The releases are operating according to the Interim Release Protocol (IRP) to draw reservoir storage toward the seasonal storage objective of 90%. Ashokan Reservoir storage is 96.4 % today. Turbidity of the water in the release channel is 16.0 NTU. The Catskill Aqueduct is online at a flow rate of 550 MGD.

NYCDEP will continue to monitor conditions and make additional adjustments pursuant to the IRP, which 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.

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.

Ashokan Release Channel reactivated

The Ashokan Release Channel has been reactivated to draw Ashokan Reservoir storage toward the Conditional Seasonal Storage Objective (CSSO) now that the Mt. Marion gauge has dropped below the action stage of 18 ft.  After the shutdown during the storm event, NYCDEP will increase the Ashokan Release Channel from 0 MGD to 120 MGD (186 cfs) starting today in a series of steps.

Ashokan Reservoir storage is 97.3% today, the CSSO is 90.0%.  Turbidity of the water in the release channel is 1.7 NTU.

The Natiional Weather Service forecast for the Mount Marion gauge predicts that the stream level will continue to decrease over the next 72 hours.

Additional adjustments may be made to releases in repsonse to reservoir and weahter conditions pursuant to the Interim Release Protocol.

Ashokan Releases shut down, 12/18

NYC DEP shut down the Ashokan Release Channel just after 6:00 AM this morning, December 18th. This is due to the Mt Marion USGS gage reaching 17 ft (1 ft below action stage). The flow was reduced from 309 cfs to zero. The release channel will stay closed until the Mt Marion water level falls below action stage and reservoir conditions are assessed. Ashokan Reservoir storage is currently at 90.5% with a 10.9 BG void.

Proposed changes to Ashokan release protocol

NYCDEP has requested a modification to the Ashokan Reservoir Interim Release Protocol (IRP).  High level changes include:

  1. the removal of the protocol to allow for Operational Releases;
  2. Modification of the Spill Mitigation Release Protocol which would require DEP to reduce the discharge to the Community Release levels should the turbidity of the Release Channel discharge meets or exceeds 20 NTU.  However, language has also been included to allow Ulster County to submit a written request to DEC and DEP for DEP to continue or restart discharge mitigation releases to achieve the void target as identified in the Conditional Seasonal Storage Objective (CSSO) when the turbidity meets or exceeds 20 NTU.

Comments can be submitted before November 2nd to:

Ken Kosinski, P.E.
Director, Bureau of Flood Protection and Dam Safety
New York State Department of Environmental Conservation
625 Broadway, Albany NY 12233

Draft Ashokan Interim Release Protocol

JOIN US for an information session

DEP and towns along the lower Esopus Creek will co-host a public information session on Nov. 18 at 6 p.m. The meeting will happen at the Frank D. Greco Memorial Senior Center in Saugerties, at 207 Market Street. DEP will share information about Ashokan Reservoir, its operations during the ongoing Catskill Aqueduct shutdown, and an overview of the rules that currently govern releases from the reservoir. Those in attendance will also learn about helpful tools for creekside residents, including real-time gage data that can be found online.

Registration is required for in-person attendance at the senior center. You can register at the following link: http://events.constantcontact.com/register/event?llr=zl6cbwuab&oeidk=a07eisnopqi82676906

The info session will be broadcast live online for those who want watch but cannot attend in person. The following link will take you to the broadcast on the night of the meeting: https://cantineveteranscomplex.webex.com/cantineveteranscomplex/j.php?MTID=mdb23091ef19fbeb0854eb25ed50201af

Public review and comment period for ashokan releases

Available for Public Review and Comment: Draft Environmental Impact Statement (DEIS) for the Modification of the CATALUM SPDES Permit, and Draft Permit. This includes Proposed Action in Lower Esopus Creek as part of the revised Ashokan Reservoir Release Protocol. Written public comments will be accepted on the Draft EIS until March 16, 2021. A virtual public comment hearing on the permit application and the Draft EIS will be held before at 4:00 P.M. on Thursday, February 4, 2021, through the Webex Events electronic webinar platform. Information on how to provide public comment and participate in the Virtual Public comment hearing can be found here.