Monitoring Reports

The rain falling across the basin today is helping to maintain flow
levels and, along with a drop in demands, is keeping utility
operations steady. The releases from the North Branch reservoirs
continue. The leading edge of the release can be seen at the Paw Paw,
WV gage on the mainstem Potomac River.

Washington Aqueduct will go off of the Little Falls pumping station
and back to Great Falls when possible. They were unable to reach the
station earlier in the day due to the triathlon taking place in the
area.

Potomac River flow at the USGS's gage station at Little Falls is now in the vicinity of 300 MGD. There may be some relief from the dry weather this weekend; the National Weather Service predicts accumulations of up to 1/2 inch of rain throughout much of the basin today and tomorrow. The release from the North Branch reservoirs will continue through the weekend.

The Jennings Randolph water supply release, which started at 8:30 AM today (September 10), is currently visible at the USGS stream gage in Luke, MD. The USGS did a rating curve adjustment that resulted in an increase of 71 MGD (110 cfs) at Point of Rocks from this morning's reading. We are watching for the arrival of the Little Seneca release at Little Falls. Past tests have indicated that the time of travel is approximately 29 hours, which would imply the arrival to be at 1:00 PM.

This afternoon we will be requesting concurrence from the general
managers for a release from Jennings Randolph beginning tomorrow
morning. The 50 MGD test release from Little Seneca Reservoir began at
8:00 AM today (September 9) and will continue through 8:00 AM tomorrow
(September 10). The release was observed by Karin Bencala of ICPRB
staff at a location approximately 1 mile downstream of the reservoir.
Flows were observed to be increasing by 9:15 AM. Black Hill Regional
Staff was setting out signs in the park notifying patrons that the

ICPRB COOP has requested concurrence from the utility general managers
to conduct a 50 MGD time of travel test release from approximately
8:00 a.m. on Thursday, September 9 through 8:00 a.m. on Friday,
September 10.

The weather update remains the same as this morning.

The basin did not receive any precipitation in the past 24 hours. Both the 48-hour and the five-day National Weather Service precipitation forecasts indicate no accumulated
rainfall in the basin, except for trace amounts in the North Branch area.

The basin continues to receive no precipitation, except for the small
amount seen yesterday. Both the 48-hour and the five-day National
Weather Service precipitation forecasts indicate no accumulated
rainfall in the basin. Given current conditions, enhanced monitoring
will likely begin tomorrow. Tomorrow we will contact the utilities
directly to confirm procedures.

Except for scattered amounts of trace rainfall yesterday, the basin has not received any precipitation over the past 7 days. The National
Weather Service predicts no precipitation in the basin over the next 48-hour period. A small amount of rain, up to 1/10 of an inch, is
being forecasted to fall in the North Branch area within the next five days. It appears that the artificially varied flow (AVF) release from
Jennings Randolph has reached Little Falls causing increased flow at the gage. It is expected that flows will drop again once the AVF

Over the last 24 hours, less than a 0.1 of an inch of precipitation fell over the mainstem of the Potomac between Goose Creek and the Monocacy; the remaining areas in the basin received no rain. Over the next 48 hours, the National Weather Service indicates a chance of up to 0.1 of an inch of rain in the North Branch, with a possibility of a 0.25 of an inch in the Washington, D.C. area. Over the next 5 days, there is a chance of up to 0.1 of an inch of rain, with most of the central portion of the basin receiving no rain.

No precipitation fell in the basin yesterday, except for an isolated amount of trace rainfall over the mainstem between Goose Creek and the Monocacy. The trajectory of Hurricane Earl remains off the coast and it does not appear that the basin will receive any precipitation from this event. The National Weather Service does indicate a chance of up to 0.10 of an inch of rain in the next 48 hours in the North Branch area. The flow at Point of Rocks reflects the artificially varied flow release reaching the gage.