North Platte Basin Roundtable 10 30 07 Final.d

• Basin Roundtable: North Platte
• Title: October 07 Minutes
• Date: 10/30/2007
• Basin Roundtables - Doc Type: Minutes

North Platte Basin Roundtable Meeting 10.30.2007 4
Pr~esentution on Forest HyrlNOlogy:
By Kelly Elder, USDA Mountain Research Station, Research hydrologist and Forest
Administrator of the USDA Forest Service Fraser Experimental Forest.
Kelly tallced about the management of the forest and how that affects water yield, also the
effects of the beetle. He will focus on the Fool Creels Study; Objective was to determine
the effect of harvesting on snow accumulation, n~noff quantity and timing, and sediment
production.
In subalpine hydrology there are 2 big players: Snow and Trees
Snow: snowpack is a natural reservoir, but we don't have much choice in the timing.
Trees: hold snow on site, change local energy balance (snow melts faster in open areas),
intercept snowfall, losses from canopy. Younger trees douse water differently than older
trees: they have a larger demand for water. Trees also catch snow in the canopy where it
can sublimate.
Forest Management: what do we know from studies?
Runoff maiupulation: people figured out that if they manage trees they can affect the
water balance.
Results of the Fool Creels study: 29% (6.0 cm) average increase in annual flow after the
cut, mostly sustained over 50 years.
*Largest differences in flow on Fool Creels still occur on years with greater total flow
(point: you see the biggest effects on wet years). The savings usually occur on the years
you don't need the water, so if you want to benefit from the savings, you have to build
storage.
Effect on timing runoff: the peak flow occurs 7.0 days earlier than pretreatment. There is
more flow, but the flow is coming in May--too early. To realize the savings you need
storage.
Hydrologic recovery: Time to recovery significantly reduced: data suggest 58 years.
Kelly thinks about 60 years. Most of Fool Creek is eveiily stocked.
If you maintain the clearcuts, you maintain the hydrologic recovery.
Now the Fraser Experimental Forest is hit by the beetles, so they won't ever lalow the
hydrologic recovery anymore than now. They also have pine beetles hitting the spruce
now also.
What do ~~~e ky~o~~~ fi~oha beetle s~t~rdies?
There are oiily a few studies existing.
1. Bethlahmy: 1975 White River, CO (controversial study due to statistics).
Take home message: you may see the same kind of flow increases from the beetle that
you see from managed basins.
22% increase in high flow rate
Showed similar numbers on the Yampa River
2. Potts: 1984, Jack Creek MT (had less than 10 years of data)