Project Summary, Quitobaquito Pond – Cottonwood Sealing, October 18 - 28, 2010
Organ Pipe Cactus National Monument. 2010. Project Summary, Quitobaquito Pond – Cottonwood Sealing, October 18 - 28, 2010
From October 18 through 28, 2010, Organ Pipe Cactus National Monument (ORPI) attempted a partial, temporary sealing of an area of Quitobaquito Pond. This was the latest phase in continuing efforts to analyze and correct an acute water-loss situation that has existed since 2006. Previous efforts included renovating the northeast spring (2007), installing a diaphragm wall inside the pond’s retaining berm (2008), thinning of encroaching bulrush (2006-2010), supplementing the pond with trucked-in water (2008-2009), and renovating the southeast corner (2009). The latter project, in August 2009, proved effective at resolving the most acute loss of water from the pond (Figure 1). Following that project, the pond level rose from minus 27” to 28” (pond largely gone, Figure 12b) to minus 12”, an increase of 15”. In early 2010, the pond surface leveled off at minus 12”, suggesting additional leakage was taking place, at or near that level, somewhere other than in the southeast corner. In late January, heavy rains over several days quickly raised the pond to nearly minus 7” (Figure 1). However, the pond surface quickly fell back to about minus 12”, indicating that a high-volume leak (>10 gpm) remained, at or near that level. The often-photographed leaning cottonwood tree rooted on the retaining berm was a top candidate for the location of the leak. Both physical and circumstantial evidence implicated this tree. Multiple trials using nontoxic tracer dye in the pond, in 2009- 2010, suggested water movement toward the tree. Photographs of the tree over nearly 100 years document its gradual lean toward, then over, then into the pond. Photographs and physical inspection revealed the scar of a large broken-off branch of the tree approximately 12” in diameter, which has been underwater since about 1969. These circumstances suggested that the gradual leaning of the tree may have compromised the retaining berm, and/or the underside of the tree trunk including the large branch scar may be rotting and opening conduits to allow water to flow from the pond, through the
- Type
- Unpublished Report
- Authors
- Organ Pipe Cactus National Monument
- Date of Issue
- 2010
- Units
- ORPI