PROJ00434

• Contract/PO #: C153337
• Contractor Name: Farmers Extension Ditch & Highland Lake Lateral Company
• Contract Type: Loan
• Water District: 1
• County: Weld
• Bill Number: FSA
• Loan Projects - Doc Type: Feasibility Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

It takes approximately ten percent (10%) of the water bought to carry the irri-

gation water through the Highland Ditch to the Highland Lake Lateral Ditch and

another ten percent (10%) to deliver the waters through the Highland Lake Lateral

to the Farmers Irrigation Ditch. With the completion of this project, there will

be a carrying water savings of ten percent (10%) throughout the irrigation season.

Based on an average usage of 22,500 acre-feet per year, the water savings will

be 2,250 acre-feet. These savings are slightly more than fifty percent (50%)

of the yearly amount of rented water. This reduction is substantial; for it is

rented water which is the most expensive.

Water is lost from the ditch by evaporation and seepage. According to studies

done by the U. S. Department of Commerce, the Average Annual Lake Evaporation

for this part of Colorado is forty (40) inches. Evaporation rates are affected

by two (2) parameters; temperature and windspeed. Because the water in the ditch

is constantly flowing, an artificial surface wind is created. Thus, there is

an increase in the amount of evaporation from the ditch as compared to a motion-

less body of water. For our project, we will conservatively estimate this in-

crease to equal ten (10) inches annually so that our yearly average evaporation

is fifty (50) inches. This figure is somewhat low due to the fact that water

flows down the ditch only during the summer months; which is the high evaporation

season. Using these figures, we find that there is an estimated loss to evapora-

tion of nearly 44.50 acre-feet. Over a four (4) month irrigation period this is

equivalent to a loss of .185 cubic feet per second or 120,000 gallons per day.

The second way that water is presently lost from ditches is through seepage.

The seepage that eminates from the ditch is becoming worse every year. The rea-

son for this is that as the water erodes the banks, less compact, more permeable

soils are exposed and vegetation is washed away. It is very difficult to esti-

mate where the water is lost to seepage. It is difficult to tell, for instance,

where the ditch still has substantial compaction left to it and where it does

not. Also seepage increases as the water level behind a check structure is raised.

This is because there is little or no compaction at the top of the embankments.

The seepage is evident throughout the fields along the ditch, there are places

within fields that show the muddy signs of seepage waters. Many of the areas

12