PERMFILE100724

• Permit No: M1980047
• IBM Index Class Name: Permit File
• Section_Exhibit Name: EXHIBIT E RECLAMATION STATEMENT OF PURPOSE
• Media Type: D
• Archive: No

• Colorado (5,830 feet) and solar radiation data from Grand Junction,
Colorado.
The resulting formulae (Wymore 1973) for estimating potential
evapotranspiration are:
Etp = (0.006T + 0.05) Rs for Nov. - March
Etp = (0.014T - 0.30) Rs for April - October
where Rs = solar plus sky radiation converted to inches of evaporation
T = mean air temperature (°F).
The vegetation of Davis Gulch is a mountain shrub type adapted
to xeric conditions. It is not lush and does not cover 100 per-
cent of the ground. Thus, the above evapotranspiration equations
were further revised to reflect the water use by the specific
vegetation types in Davis Gulch. This resulting equation is:
•
Et = KCEtp
where ET = Evapotranspiration for a specific vegetation
type with water not limiting.
where Kc = A water use coefficient for given plants.
* r
The actual evapotranspiration under present conditions for the
Davis Gulch watershed is based on the mean annual precipitation
for the area so that evapotranspiration is limited by precipitation.
The present condition water balance is:

E-25