COLORADO IRRIGATION WATERS AND THEIR CHANGES. 21 
TABLE VIII.—ANALYSIS OF WATER TAKEN FROM THE 
LARIMER & WELD RESERVOIR (TEhKY LAKE), 
Grs. 
Combined. Per Imp. 
Cent. Gal. 
Calcic Sulfate_ 21.606 37.940 
Strontic Sulfate_ 0.346 0.608 
Magnesic Sulfate.__ 39.136 68.723 
Potassic Sulfate... 0.663 1.164 
Sodic Sulfate_ 26.224 46.049 
Sodic Chlorid_ 1.439 2.527 
Sodic Carbonate_ 4.667 8.195 
Sodic Silicate_ 0.237 0.416 
Ferric and Alu. Oxids 0.063 0.111 
Manganic Oxid_ Trace Trace 
Ignition_ 5.441 9.554 
Analytical 
Per 
JULY 
Grs. 
Imp. 
Results. 
Cent. 
Gal. 
Silicic Acid... ___ 
... 0.117 
0.205 
Sulfuric Acid 
... 53.967 
94.766 
Carbonic Acid 
... 1.936 
3.400 
Chlorin 
... 0.872 
1.530 
Sodic Oxid 
... 15.071 
26.465 
Potassic Oxid 
.. 0.359 
0.630 
Calcic Oxid 
.. 8.893 
15.616 
Strontic Oxid 
.. 0.196 
0.344 
Magnesic Oxid 
.. 13.104 
23.011 
Ferric and Alu. Oxids 0.063 
0.111 
Manganic Oxid. 
Trace 
Trace 
Ignition 
.. 5.441 
9.554 
Sum. 
.. 99.822 1 
'75 632 
Total. 
...99.822 175.632 
Total ....99.822 175.287 
Total solids, I75.fi grains per imperial gallon. 
SANITARY A ALYSIS. 
Parts Per Million. 
Total Solids_2,508.570 
Chlorin_ 28.290 
Nitrogen as Nitrates.0.100 
Nitrogen as Nitrites_ 0.010 
Parts Per Million. 
Saline Ammonia_ 0.100 
Albuminoidal Ammonia.__ 0.600 
Oxygen required__ 2.283 
§ 40. Taking the average of the total solids obtained for 
these two years, 1900 and 1902, determined in each case when the 
lake was full, we have 155.02 grains per gallon. The present 
capacity of the lake being 9,000 acre-feet, these figures give us 
27,127 tons as the amoumt of mineral matter, only 507.5 tons of 
of which was originally contained in the water, assuming it all to 
have been taken from the river. This large amount of salts, 
27,127 tons, is annually distributed over the land irrigated by this 
water, or about three tons per acre-foot. At the present time we 
are less concerned with its distribution, which we will discuss 
later, than with the question of its source. It matters not whether 
it is storm water or river water; neither of these contains the fiftieth 
part of the salts here represented. If it were all river water con¬ 
taining 2.9 grains per gallon, it would account for oniy about 507 
tons, leaving 26,620 tons to be derived from the seepage of a com¬ 
paratively small area of country. If the whole of the Dry creek 
seepage were turned into the reservoir, its volume would not seem 
to be large enough to account for this result. The distance from 
Terry lake to the North Poudre canal is less than nine miles, and 
the average width of country which seeps or drains into it is not 
more than three and one-half miles, at the most thirty-two square 
