This weekend is a great example of the imprecise guessing game that the Delaware River Master and NYC reservoir managers are faced with when they make water release decisions based on weather forecasting to address the Montague (NJ) minimum flow target. With some frequency over the decades, these forecasting predictions often result in "Yo-Yo" water releases from the NYC reservoirs that cause rapid and erratic fluctuations in river flows and can have very damaging impacts on the cold water ecosystem of the Upper Delaware River.

The decision to dramatically drop the release from Cannonsville reservoir in recent days was based on a forecast of rain that did not materialize. Yesterday, to compensate for the forecasting miscalculation, reservoir managers chose to temporarily and substantially increase the release (54 mgd to 894 mgd) to help meet the Montague target. And now a new weekend forecast of more rain lead to a dramatic decrease in the release (894 mgd to 54 mgd) between the hours of 10pm last night (Friday) and 10am this morning (Saturday).

As NYCDEP acknowledges in their public statement (See NYCDEP web site), this will likely cause a "Yo-Yo" impact on the river which is of particular concern because it occurs during the spawning period for wild brown trout in the UDR. Beyond fish, many aquatic biologists have observed that these kinds of dramatic, short-term fluctuations in releases/flows are among the most harmful impacts to tail water systems across the country and can cause widespread ecological damage.

It is worth noting that we discussed this very issue at FUDR's annual conference this week specifically regarding impacts to the dwarf wedge mussel, a federal and state listed endangered species, as a result of the recent dewatering of the UDR system due to the month long drawdown of Lake Wallenpaupack coinciding with very dry weather. The Wallenpaupack draw down helped satisfy the Montague target and resulted in low releases from the NYC reservoirs to the Upper Delaware River above the Lackawaxen River. Unfortunately, the authorities with responsibility to manage and protect the Upper Delaware River did not anticipate the possibility of dry conditions during the Wallenpaupack draw down and consequently had no response plan for the damaging consequences to the upper river.

FUDR, Trout Unlimited and the UDR conservation community have consistently called for gradual ramping of releases in these situations to better mimic a natural system particularly when the water is shut off at the reservoirs on the back side of the release. However, the authorities have failed to develop and implement a ramping protocol that would avoid these negative impacts on the river. We have also asked them to wait until the rain actually happens before they make water release adjustments in these situations. In addition, for many years, we have called for weekly averaging of the Montague target which would remove the need for precise day to day forecasting analysis and help eliminate the need for" Yo-Yo" releases.

It is with great frustration that we relay this news because "Yo-Yo" releases and their harmful impacts on the river are not a new problem yet very little has been done to eliminate them even though solutions are available. This is a problem that must be addressed as Decree Party negotiators formulate the next Flexible Flow Management Plan.

For the river,