Difference between revisions of "TEMPERATURE"

From Glen Canyon Dam AMP
Jump to: navigation, search
Line 26: Line 26:
 
Prior to completion of Glen Canyon Dam in 1963, the temperature of water flowing through the Grand Canyon each year was highly variable, ranging from the icy, spring run-off to the warm, 85-degree summer-heated flows.
 
Prior to completion of Glen Canyon Dam in 1963, the temperature of water flowing through the Grand Canyon each year was highly variable, ranging from the icy, spring run-off to the warm, 85-degree summer-heated flows.
  
However, once the dam was constructed, the temperature of the water released from the dam - drawn from the depths of Lake Powell and released through the dam's large penstock intakes - ranged for many years between 45 to 50 degrees. With the lowering of Lake Powell, release temperatures have been increased to as high as 57 degrees which has likely led to an increase in the humpback chub and other native fish populations in Grand Canyon.
+
However, once the dam was constructed, the temperature of the water released from the dam - drawn from the depths of Lake Powell and released through the dam's large penstock intakes - ranged for many years between 45 and 50 F (7 to 10 C). With the lowering of Lake Powell, release temperatures have been increased to as high as 59 F (15 C) which has likely led to an increase in the humpback chub and other native fish populations in Grand Canyon. These increases in temperature, however, also increase the risk of expanding the distribution and abundance of cool/warm-water nonnative fish like [http://www.usbr.gov/uc/rm/amp/twg/mtgs/16jan26/documents/Attach_05.pdf| brown trout], [[Green_Sunfish_Page| green sunfish]], smallmouth bass, and walleye which could have a devastating impact on the humpback chub population in Grand Canyon like they have in the Upper Basin.  
  
 
|}<!--
 
|}<!--

Revision as of 16:29, 19 July 2016


1948 2006 MainstemTemp.jpg

Prior to completion of Glen Canyon Dam in 1963, the temperature of water flowing through the Grand Canyon each year was highly variable, ranging from the icy, spring run-off to the warm, 85-degree summer-heated flows.

However, once the dam was constructed, the temperature of the water released from the dam - drawn from the depths of Lake Powell and released through the dam's large penstock intakes - ranged for many years between 45 and 50 F (7 to 10 C). With the lowering of Lake Powell, release temperatures have been increased to as high as 59 F (15 C) which has likely led to an increase in the humpback chub and other native fish populations in Grand Canyon. These increases in temperature, however, also increase the risk of expanding the distribution and abundance of cool/warm-water nonnative fish like brown trout, green sunfish, smallmouth bass, and walleye which could have a devastating impact on the humpback chub population in Grand Canyon like they have in the Upper Basin.

---
---
---

Updates

2016 ModeledRiverTemps.jpg
The timing of when releases are the warmest and when warm air temperatures have the greatest potential to warm the river has a large influence on downstream river temperatures. The warmest release temperatures occur in late October/early November but the greatest potential of warming the river in Grand Canyon occurs in July and September when air temperatures are the hottest. The reason is that it takes a lot longer to warm all the water in Lake Powell vs the water in the river as it flows downstream.

News


Mainstem Temperature at the LCR 1990-2015: Temperatures on the Rise

Temperature bl LCR 1990 2015.jpg


Temperature Gages


Papers and presentations

2013

2010


Other Stuff