Glen Canyon NRA Releases EA on Castle Rock Cut Deepening
Glen Canyon National Recreation Area officials want to spend roughly $750,000 to deepen the so-called "Castle Rock Cut" so boaters can gain quicker access to the main reservoir of Lake Powell from Wahweep Bay.
Under the environmental assessment released today, NRA officials plan to deepen the cut by 35 feet over a five-year period. The channel was originally excavated to an elevation of 3,622 feet in the 1970s to allow boats to traverse the cut at a lake level of 3,627 feet or higher, and then down to 3,615 feet in 1993.
However, continued drought in the Southwest has made the cut impassable continuously since 2003, according to the Park Service. Without that short cut, boaters have had to run 12 miles through Antelope Canyon to reach Warm Creek Bay and other up-lake destinations.
To address this detour, the Park Service wants to deepen the cut down to an elevation of 3,580 feet, a project that would entail removing approximately 400,000 cubic yards of Navajo sandstone bedrock.
This has been a somewhat controversial topic on the Traveler. Just read the comments that were appended to the initial post when Glen Canyon officials voiced this proposal back in November. However, during the public comment period far and away those who took the time to comment were in favor of deepening the cut.
Approximately 1,470 responses (out of roughly 1,630 received) were in favor of the project, stating that proceeding with the project would improve boater safety, particularly when passing through the Channel; reduce fuel and boat maintenance costs; reduce emissions; reduce water and air pollution caused by boats traveling uplake via the longer route through the Channel; reduce travel time to uplake destinations; and benefit the local economy.
... Approximately 149 responses were opposed to the project, in general stating that the project
would violate NPS mandates; favor one group of recreationists (i.e., boaters versus hikers,
birdwatchers, etc.); create pollution and cause damage to the lakeshore to effect a short-term
solution to a temporary drought; be a waste of taxpayer money and park economic resources;
harm threatened or endangered species and other natural resources; and negatively impact the
aesthetic and backcountry values of Glen Canyon NRA.
Of course, if this winter's heavy snowpack is repeated next winter, there might not be a need to deepen the cut. But Park Service statisticians don't think that will be the case. According to their estimates, there's only a 60 percent chance that Lake Powell's surface elevation will reach 3,620 feet on September 30 -- typically the high-water mark during the year -- during the years 2008-2012, and only a 62 percent chance if you run that out to 2017.
At the same time, they say there's only a 40 percent chance that the lake's elevation will stand at 3,620 feet on March 30 -- typically the year's low-water mark -- during the years 2008-2012. That possibility rises to only 50 percent if you run that out to 2017.
(The probabilities based on 100 modeling runs using inflow and lake level elevation data from 1906 to 2005. Model does not take into account potential long-term climate change, including global warming. Modeled elevations are based on existing and target excavation depths, with 5 feet added as a minimum freeboard for passage of houseboats and personal watercraft (Reclamation 2007c).)
The Park Service will take comments on this plan through March 20. You can submit yours at this site.