Number of days from spring canal runs to moderate (<−0.30 MPa) and severe (<−0.50 MPa) water stress based on predawn leaf water potentials (Ψpd) of plains cottonwoods within each canal section along the High Line Canal, Denver, Colorado, U.S. (1998–2008). Yearly days and mean over all years are presented. SE = standard error; hyphen (−) = data not collected.
| Canal section | Year | Sites (n) | Days of canal water | Days to moderate stress | SE | Sites with severe stress (n) | Days to severe stress | SE |
|---|---|---|---|---|---|---|---|---|
| Cherry Creek | 1998 | 7 | 79 | 46 | 1.3 | 0 | 0 | |
| 1999 | 7 | 146 | 60 | 2.9 | 4 | 74 | 0.8 | |
| 2000–2003 | - | - | - | - | - | - | - | |
| 2004 | 7 | 14 | 22 | 2.9 | 3 | 26 | 5.1 | |
| 2005 | 7 | 50 | 25 | 1.3 | 5 | 48 | 6.5 | |
| 2006 | - | - | - | - | - | - | - | |
| 2007 | 7 | 21 | 14 | 1.5 | 7 | 43 | 3.5 | |
| 2008 | 7 | 21 | - | - | 7 | 23 | 4.6 | |
| Mean (all years) | 33.4 | 8.2 | 42.8 | 8.7 | ||||
| Toll Gate Creek | 1998 | 2 | 79 | 54. | 10.6 | 1 | 60 | - |
| 1999 | 5 | 56 | 28 | 4.5 | 2 | 92 | 7.1 | |
| 2000 | 6 | 24 | 74 | 1.6 | 0 | no | - | |
| 2001 | 3 | 64 | 46 | 9.1 | 1 | 81 | - | |
| 2002 | 2 | 0 | 0 | 0 | 2 | 14 | 13.6 | |
| 2003 | 4 | 14 | 50 | 5.4 | 3 | 66 | 5.5 | |
| 2004 | 4 | 0 | 16 | 1.5 | 0 | no | - | |
| 2005 | 4 | 50 | 38 | 1.8 | 2 | 38 | 5.1 | |
| 2006 | - | - | - | - | - | - | - | |
| 2007 | 4 | 14 | 18 | 2.0 | 3 | 60 | 7.8 | |
| 2008 | 4 | 14 | - | - | 2 | 35 | 8.0 | |
| Mean (all years) | 40.4 | 7.4 | 56.0 | 8.8 | ||||
| Sand Creek | 1998 | 4 | 79 | 56 | 4.5 | 2 | 62 | 2.5 |
| 1999 | 4 | 56 | 58 | 8.4 | 2 | 92 | 3.7 | |
| 2000 | 6 | 24 | 72 | 3.3 | 4 | 78 | 3.3 | |
| 2001 | 6 | 30 | 46 | 2.4 | 3 | 47 | 6.1 | |
| 2002 | 6 | 0 | 0 | 0 | 6 | 20 | 5.1 | |
| 2003 | 4 | 7 | 36 | 5.8 | 3 | 76 | 29.4 | |
| 2004–2006 | 3 | - | - | - | - | - | - | |
| 2007 | 3 | 0 | 4 | 2.9 | 2 | 18 | 3.5 | |
| 2008 | 3 | 0 | 0 | 0 | 1 | 15 | - | |
| Mean (all years) | 45.0 | 8.9 | 50.9 | 11.1 |