Bear Creek Snowpack vs. Flow data analysis

[deepsouthpaddler]

April is prime to to let your inner gauge geek rage. After some much needed spring storms, the inevitable question for front range boaters is... will bear creek run?

After searching through the snotel data, it appears that the Echo Lake snotel site, is the best site to use for Bear Creek analysis. The Echo Lake snotel site is located about 5 miles NW of Mt. Evans and is in the Bear Creek drainage. Attached is a map that shows the location of the snotel site relative to Bear Creek.



I pulled echo lake snotel data from 1999-2008, and compared the snowpack data to estimated peak flow during runoff from the bear creek at morrison CODWR gauge. I removed two outlier data points, and the correlation is reasonable. You can use this plot to get a general idea of what kind of snowpack you need on the echo lake snotel gauge to get certain peak flows on bear creek. It should be noted that I neglected the monsoon rain peaks in July/Aug as those are driven by rain, and independent of snowpack.



The sad news for Bear Creek for the 2009 season is that the current snowpack on the Echo Lake snotel looks to be about 50% of average. Bummer. Based on the correlation of snowpack to peak flows, we can expect a peak flow on Bear Creek of about Jack Squat CFS.



Anyway, bad news for this year, but good information to have. In the future, look for 125% of average or above on the Echo Lake snotel site for a potentially decent Bear Creek season. For reference, the 2007 banner Bear Creek season had 168% of avg on the Echo Lake site, and was the largest snowpack the site had in a decade. We can still hope for monster upslope storms and massive monsoon rains...

[TheKid]

Dude awesome work. Let the gauge geek rage! Well done!

[benrodda]

You probably know this but I figured I would throw two thoughts in:

1. Echo lake runs into Idaho Springs. It does provide a decent reference for snow pack however it varies fairly significantly from one side of the mountain to the next. As well I think that the watershed for Bear creek is actually significantly larger than the watershed for that area. I know because I lived up there.

2. The damn that they snuck in for Gennessee will prohibit Bear creek from ever running again. Some people disagree. If any one can find out what its capacity is versuses its current level, then determine how much water they are allowed to draw from run off you will have a better idea. The last part of the puzzle is actual snowpack... Even if the snowpack was huge i am betting that the flow will be sucked up by Genessee people leaving only enough water for fish to survive untill someone feels like tearing their lips off.

3. Last year was not the best year as a point of reference either. They were filling the resevoir and took a good bit of run off. As well the run off trickled last year. For bear creek to run it needed to be above freezing at night or rain. We never really got a good heat wave to thaw it out quickly enough to see it high enough. This was the case throughout the state. Everyone thought it was going to be an epic year with they way snow pack was but because the weather was so mild we never really had a peak... instead we had three.

just my thoughts.

[DanOrion]

The new Genesee Dam is 101 af....or 50 cfs for one day...or 25 af for two days...or 5 cfs for 10 days. I don't know what the pump capacity is to the dam, since it's off channel, but I'll bet its on the order of 5 cfs or less.

Genesee Water & Sanatation District

Bummer that Bear won't run. Maybe they'll make a "damn release"

[xkayaker13]

Ian, that's some awesome work. Thanks for the graphs, my finance professors would be proud. Hopefully I'll see you soon on the river!

[crackeryaker]

thanks for putting that up! I have been getting curious about Bear...thanks for the clarification on the damn as well.

[thecraw]

Ian... just the fact that you put that much time in to this get's me SO F"N STOKED! The fact that Bear will be hindered by that damn dam does not have me stoked. Could be a good mission for AW here locally to get involved and finger out if a solution is possible?

[crane]

so you are saying purely on speculation that the pump may run at 5 cfs. if bear creek were to "run" it would need at least 175 cfs. so 5 cfs is a drop in the bucket. right??? or do they turn the pump up if the flow increases. just wondering. i want that thing to run this year!

Originally Posted by DanOrion

The new Genesee Dam is 101 af....or 50 cfs for one day...or 25 af for two days...or 5 cfs for 10 days. I don't know what the pump capacity is to the dam, since it's off channel, but I'll bet its on the order of 5 cfs or less.

Genesee Water & Sanatation District

Bummer that Bear won't run. Maybe they'll make a "damn release"

[DanOrion]

I'm pretty damn sure that the Genesee Dam doesn't fill at a rate of more than a few cfs. Genesee's engineering report (from their website) points to 1000 gpm, or about 2.2 cfs. They probably need about 7 horsepower per cfs for pumping. Even if the Genesee Dam could divert lots of water, say 50 cfs (with a 350 horsepower pump), it could only divert that much for one day because the reservoir is only 100 cfs.

Bothering AW with this topic would be a waste of their time. It's a nothing burger. Seriously.

Nice analysis Ian. Do you have a graph with the outliers? Statistically insignifigant minds are curious.