- bull trout habitat on lake creek.
All of the water the Metolian resort would use presently recharges shallow aquifer supplies the Lake Creek system, particularly the North Fork of the creek. The stream that the Metolian would divert water from is a small, seasonal unnamed stream. This year the full flow of this seasonal stream has entirely percolated into the ground before reaching any other perennial stream. The majority of this water percolates into the ground within the watershed of Lake Creek less than one mile from the North Fork of Lake Creek.
The impact of the Metolian's water diversion between March 1st and June 30th will reduce the discharge of groundwater to Lake Creek--not during the spring when flows are high but much later, in summer and fall when stream flows are low. Adequate water in Lake Creek is critical for fish that spawn in the fall.
To compare the volume of the resort's diversion of the small, seasonal unnamed stream to the volume of the Metolius River at the Allingham gauge is meaningless. The comparison must be made to the North Fork of Lake Creek where the impact will occur.
The Metolian resort would divert an average of 0.66 cubic feet per second (cfs) of the seasonal stream for 122 days (160 acre feet). This diversion would reduce the North Fork flow by approximately 7% during late summer and fall. This is based on the Lake Creek gauge data from 2000 to 2008. The North Fork is approximately 25% of the total Lake Creek flow.
During the drought of the early 1990's, the Lake Creek monthly minimum flows in August, September and October were approximately 23 cfs. In these recent drought years the Metolian resort diversion would have reduced the North Fork of Lake Creek flow by approximately 10%.
Reductions in the flow of the North Fork will also result in reduced flows at Spring Creek and Cold Springs further downstream as their flows are connected. This fisheries habitat is very important to the native, ESA-listed bull trout, and the Chinook and sockeye salmon reintroduction effort.
The Metolian resort water plan estimates the flow of the seasonal stream using the indirect proportionate method because there is no data available that documents the flow of the seasonal stream. The proportionate method simply estimates the flow of the seasonal stream by calculating its flow as a percentage of the measured flow at the Lake Creek gauge. The percentage factor is based on a simple acreage comparison of the unnamed stream basin above the Metolian's diversion point to the acreage of the Lake Creek basin above the gauge.
The proportionate method is valid only if the two basins share the same characteristics. These two basins do not share many important characteristics. One important characteristic that is not shared is a similar distribution of ground surface slope. A greater proportion of the Lake Creek basin has shallower slopes than the unnamed stream basin, thus the Lake Creek basin has slower direct water runoff. Secondly, the Lake Creek basin has a much greater percentage of storage area with its two large lakes, Suttle and Blue, and many smaller lakes, ponds and wetlands. The use of the proportionate method greatly over estimates the flow of the seasonal unnamed stream crossing the Metolian property.
In addition, the use of the proportionate method does not establish the reliability of the seasonal stream as a water supply for the resort. Based on observations and measurements I made this spring, the seasonal unnamed stream will very likely not flow for the entire four months that they would be allowed to divert it even in a good water year. In a drought period the flow will be even less and the resort will ultimately have to depend on water wells.
It is telling that the developer has not applied for a right to divert the seasonal stream, but has applied for a groundwater right for two wells. The developer has repeatedly claimed groundwater will be used and yet they have started the process to gain the right to use groundwater from wells. They say one thing do another.
Mark Yinger is a Sisters-area hydrologist who has studied the impacts of Destination Resorts on ground water levels in Central Oregon, and was hired by opponents of the Thornburgh Resort outside Redmond.