months of 1911 and 1912 was still affected. Thus, the estimates of flow probably do not represent that to be expected during ordinary years or even ordinary low years. In the absence of further data the estimated flow for ordinary low years has been based on the mean of the lowest monthly flow in 1910, 1911, and 1912.

The following table shows the estimated power at the dam sites described previously:

There have been compiled from various sources approximate elevations at different points along Embarrass River, which is tributary to the St. Louis. From these approximate data the following table of elevations and distances has been compiled:

Elevations and distances along Embarrass River from mouth to Sec. 5,

From the preceding table it is seen that the best opportunity for power development on the Embarrass is between the outlet of Esquagama Lake and the mouth, where the river has a fall of 36 feet in four miles. As no records of flow of the river are available, no estimate of available horsepower has been made.

SANITARY STATISTICS.

To show the sanitary quality of the water in St. Louis River, and the extent to which it is used for municipal purposes, data showing the source of municipal supply and disposal of sewage have been compiled for all towns of 500 inhabitants, or more, located on the river or its tributaries. These data are given in the following table in order of location, beginning near the source:

Municipal water supply and sewage disposal of towns on St. Louis River and tributaries.

From the preceding table it appears that no urban sewage enters St. Louis River above the mouth of Partridge River. The rural population is very small being 1.7 per square mile. During the winter months this population is increased by the presence of logging crews, which operate extensively in this basin.

At the mouth of Partridge River is received the drainage from 178 square miles, which contains untreated sewage from Aurora

located 5 miles above the mouth of the river. As Partridge River drains a portion of the iron range, it has a rural population of 14.3 per square mile.

From Partridge River to Floodwood, a distance of 88 miles, no urban sewage enters St. Louis River direct, but the water is polluted by the drainage of the various tributaries. Twenty-one miles below the Partridge, Embarrass River brings into the St. Louis. the drainage from 165 square miles, containing untreated sewage from Biwabik, a town of 1690 inhabitants located 17 miles above the mouth. However, as much of the channel of Embarrass River below Biwabik is through a chain of lakes where sedimentation is an active factor, it is probable that much of the sewage pollution is removed before reaching the St. Louis. The rural population of this basin is 12.2 per square mile.

Nineteen miles below the Embarrass, East Two Rivers brings in the drainage of 66 square miles, containing untreated sewage from Virginia and Eveleth, representing an urban population of 17,500. This basin has a rural population of 34.1 per square mile as it is nearly all included in the iron range district.

One mile below East Two Rivers, West Two Rivers enters with the drainage from 88 square miles. This contains the untreated sewage from Buhl, a town of 1005 inhabitants, located 20 miles below the mouth. Only the upper portion of this basin is within the range district, and therefore the rural population is only 12.2 per square mile.

East Swan River enters 22 miles below West Two Rivers and brings into the St. Louis the drainage from 250 square miles. This river contains raw sewage from Hibbing, representing a population of 8832, and treated sewage from Chisholm with a population of 7684. As nearly all the drainage area is within the range district, the rural population is high, being 40.3 per square mile.

From the mouth of Partridge River to Floodwood, a distance of 88 miles the St. Louis has an average fall of 1.6 feet per mile which insures the presence of sewage pollution from the various tributaries reaching Floodwood.

Although there are no towns located on the St. Louis above Floodwood, the presence of the iron range increases the rural population of the St. Louis basin from 1.7 per square mile above Partridge, to 15.8 per square mile, above East Swan River. From the mouth of East Swan River to Cloquet, a distance of 62 miles, the river receives no additional urban sewage. The rural population of this portion of the basin is less than that above, being 11.0 per square mile for the entire area above Cloquet. The average fall in the river in this section is 1.1 feet per mile. The lower 4.7 miles

of the distance is within the mill pond created by the upper dam at Cloquet. The average width of this pond is about 700 feet.

At Cloquet, the river receives untreated sewage from a population of 7031. This is the last source of urban pollution, as below Cloquet, there are no towns on the river or on tributaries entering below. As the river below Cloquet has a heavy fall it is probable that the sewage pollution from that source is found at the mouth of the river.

No water from the St. Louis or its tributaries is used for municipal purposes.

WHITEFACE RIVER.

SOURCE, COURSE AND TRIBUTARIES.

Whiteface River rises in Jack Pine Lake in sec. 4, T. 57 N., R. 12 W., on the eastern edge of St. Louis County and flows in a generally, though winding, southwesterly course, entering St. Louis River in sec. 24, T. 52 N., R. 20 W. Its chief tributaries are North Branch, Paleface River and Bug Creek.

TOPOGRAPHY, GEOLOGY AND FORESTATION.

The upper portion of the basin is rugged but this ruggedness gradually becomes gently undulating toward the mouth of the river. Elevations range from 1200 to 1800 feet. The entire area is covered with a thin layer of red till, a mixture of sand, clay, and gravel. In the upper portion of the basin it is underlain by gabbros of the Cambrian system. The lower half of the basin is flat and contains large areas of muskeag, due to inadequate natural drainage. The drift sheet in this portion of the area is much thicker than in the remaining portion.

The entire area is forested with dense areas of pine, balsam, spruce, cedar and tamarack. There are dense areas alternating with areas where the growth is thin. The basin has been cut over extensively but very little of the land has been cleared.

RAINFALL.

The mean annual rainfall increases from 28 inches at the mouth to 31 inches or more at the upper edge of the basin.

REGULATION OF FLOW.

The few lakes and the large swamp areas in the lower part of the area tend to equalize the flow to a certain extent. This effect is more than offset by the logging dams located as follows: on Whiteface River in sec. 2, T. 54 N., R. 16 W.; on Paleface River in sec. 36, T. 56 N., R. 16 W.; on Bug Creek in sec. 21, T. 54 N., R. 16 W. These dams control the flow from 215 of the 522 square miles

drained by Whiteface River. The operation of these dams increases the inequality of the flow by storing water during the winter time which is the period of natural minimum flow, and releasing this stored water in the spring to increase the natural highwater flow.

The Minnesota Forest Service has made the following estimate regarding the log driving on the Whiteface and its tributaries: 1909, 21,314,360; 1910, 9,997,780; 1911, 13,733,150 feet B. M.

DRAINAGE WORK.

Although there are large swamp areas in the basin, very little land has been drained as through a lack of settlers very little of it has been cleared.

WHITEFACE RIVER AT MEADOWLANDS.

Location. -At the highway bridge at Meadowlands, in Sec. 14, T 53 N, R 19 W, 1⁄2 mile below nearest tributary, a small stream entering from the east.

Records available.-June 7, 1909, December 31, 1912.

Drainage area. -442 square miles.

Gage. Vertical staff; datum unchanged since establishment.

Channel. May be shifting at bridge; nearly permanent at control point. Discharge measurements.-Made from highway bridge except during extremely low water when wading measurements are made.

Regulation. The flow is controlled to a large extent by logging dams above. The opening and shutting of the gates of these dams causes a fluctuation in gage heights of several feet at the gaging section. Accuracy. Logs collect on the control point some 2 miles below the gage causing varying amount of backwater at the gage. Prior to 1912, the flow during such periods of the year has been computed from a number of rating curves, some of which have been applied indirectly. During 1912, the flow during periods of backwater has been computed using gage height at a chain gage established below the rapids applied to a rating curve which has been developed for that point.