Reservoir No. 5.

This large reservoir was originally designed by the city of Boston for the storage of the water from a portion of the Sudbury watershed, but it will also be valuable in connection with the metropolitan system of works, particularly in the next few years, before the storage reservoir upon the Nashua River is ready for use.

The construction of this reservoir involves the building of a dam, to retain in the deepest place about 65 feet of water, and the removal of trees, bushes, soil and muck from the area to be flooded with water. The soil and muck removed in the improvement of the reservoir are deposited where the water would otherwise be shallow, and faced with gravel, so that the reservoir will be surrounded with gravelly shores. Where the depth of water would otherwise be less than 8 feet, the reservoir is being excavated to this depth. Plan No. 4 shows the form which this reservoir will have when completed by the filling of the shallower portions, and shows the portions excavated and to be excavated.

The first contracts for the construction of this reservoir were made by the city of Boston, as follows: one large contract for the dam, in 1893, although work upon it was not begun until 1894; three contracts in 1894, one of them for the improvement of the reservoir and two for other work connected with the reservoir and dam; and ten contracts in 1895, seven of which were for the improvement of the reservoir and three for building roads, fences and filter beds.

On Jan. 4, 1896, when the work of constructing this reservoir was transferred to the Metropolitan Water Board, there were in force one large contract for the construction of the dam, eight important contracts for improving the reservoir and two minor contracts. These contracts were assumed by the Metropolitan Water Board, under the provisions of the metropolitan water act.

During the year 1896 the Metropolitan Water Board made eleven additional contracts, nine of which were for improving the reservoir, one for building an arch under and widening the embankment of the New York, New Haven & Hartford Railroad, where it crosses the reservoir, and another for sluice gates for the dam.

The following statement gives the gross amount of the contracts made by the city of Boston and in force at the time the works were taken by the Metropolitan Water Board, the amount of work done upon these contracts before they were taken by the Metropolitan

Water Board, and the total amount of the contracts assumed and made during the year. The figures given are the nearest approximations to the final amount of these contracts which can be made at the present time: —

Reservoir No. 5 Contracts.

Total amount of the uncompleted contracts of the city of Boston,
Amount of work done on these contracts by the city of Boston,
Amount of work remaining to be done by the Commonwealth,
Contracts made by Metropolitan Water Board,

Total amount of contracts made or assumed by Metropolitan
Water Board,

$1,051,903 54

512,000 00

$539,903 54

800,720 71

$1,340,624 25

The progress on the contracts, as a whole, has been very satisfactory. The value of work done upon the contract for Dam No. 5, up to Jan. 4, 1896, was about $284,000, and the amount done from Jan. 4 to Dec. 15, 1896, was about $220,000. The work on this dam is nearing completion, and it should be finished within two months after resuming work upon the masonry next spring.

The improvement of the reservoir required the removal of 4,544,000 cubic yards of earth. Prior to Jan. 4, 1896, the city of Boston had removed 761,000 cubic yards; from Jan. 4 to Dec. 1, 1896, the amount removed under the direction of the Metropolitan Water Board was 2,016,000 cubic yards, leaving 1,767,000 cubic yards to be removed. The contracts provide that all of this earth shall be removed before Dec. 1, 1897, and the rapid progress made upon the work this year indicates that the work will be completed on or before the time stated.

Under a requirement of the existing contracts, the improvement of the reservoir has been practically completed up to a level 18 feet below the top of the dam, so that the reservoir can be partially filled in the spring of 1897, thereby furnishing a much-needed addition to the water supply of the city of Boston. It is expected that all of the work connected with the reservoir will be completed during the coming year, so that it may be filled in the winter and spring of 1898.

Distribution.

The completion of the Nashua Aqueduct and of Reservoir No. 5 will furnish a sufficient supply of water at Chestnut Hill Reservoir in Boston. From this point the water is to be pumped and con

veyed through pipes to the cities and towns of the metropolitan water district. It is the aim to construct the pipe systems so that they will be ready for use by the end of 1897; but, on account of the time required to perfect plans for pumps and pumping stations and to construct and erect pumps, it will not be feasible to have any new pumps ready to operate upon the completion of the pipe lines. The surplus pumping capacity of the high-service pumping station of the city of Boston at Chestnut Hill Reservoir can be utilized to pump water for the cities and towns outside of Boston; and as these pumps will connect with Spot Pond, which has a very large capacity for a distributing reservoir, it will be feasible to maintain a supply in this way until additional pumps are ready for use. In carrying out this plan, the completion of one of the lines of 48inch pipe from Chestnut Hill Reservoir to Spot Pond is a most important factor, and much of the work during the year has been done on this line.

The principal contracts made during the year in connection with the distribution of water may be summarized as follows:

11 contracts with four pipe foundries for furnishing 42,875 tons of cast-iron water pipe, ranging in diameter from 48 inches to 6 inches; the total amount of these contracts is.

8 contracts for pipe laying, representing a total of 19.7 miles of pipe, varying in diameter from 48 inches to 16 inches; the total amount of these contracts is .

$869,424 86

5 minor contracts,

166,836 33 18,279 59 $1,054,540 78

The progress on these contracts has been very satisfactory, as up to the end of the year 1896 the total quantity of pipe inspected and accepted amounted to 38,080 tons, and the amount of pipe laid equalled 15 miles. The amount of pipe now on hand in the pipe yards in Somerville and Edgeworth equals a length of 13.8 miles, and the additional length contracted for, but not yet received at the pipe yards, equals 4.1 miles.

The total length of the 48-inch pipe line now being laid from Chestnut Hill Reservoir to Spot Pond is 11.7 miles, of which 7.56 miles have been laid, and existing contracts cover an additional 1.67 miles, leaving 2.45 miles for which no contracts have yet been made. The pipes across the Charles and Mystic rivers are included in the lengths for which contracts have not yet been made.

It is expected to so far complete the pipe systems during the year 1897 that water can be distributed to the cities and towns in the metropolitan water district in 1898.

Summary of Contracts to Nov. 30, 1896.

The contracts made and assumed by the Metropolitan Water Board from Dec. 27, 1895, when the first contract for construction was made, to Nov. 30, 1896, may be summarized as follows:

Reservoir No. 5, assumed from the city of Boston

(uncompleted portions), .

11

539,903 54

Reservoir No. 5, made by Metropolitan Water Board,

Value of work done on these contracts to dates of
December estimates,

$2,029,022 12

Force Employed on Works.

The largest force employed upon the works at any one time during the year was in the latter part of October, 1896, as follows:

A detailed statement of the work done in the different departments of the engineering force is as follows:

RESERVOIR DEPARTMENT.

HIRAM A. MILLER, Department Engineer.

In this department is included the greater part of the work to be done in connection with the construction of the reservoir upon the Nashua River above Clinton, exclusive of the dam. The work upon the reservoir was, as already stated, temporarily in charge of Mr. T. F. Richardson, until May 21, when Mr. Hiram A. Miller was appointed in charge of this work, reserving, however, to Mr. Richardson the completion of the borings and other investigations to be used as the basis for locating and designing the dikes. Statements with regard to the dikes will, therefore, be found under the head of the dam and aqueduct department.

The work in this department has been almost wholly of an engineering nature, as the work of construction has not been begun. The force during the greater part of the year has been organized as follows: 1 department engineer; 4 assistant engineers in charge of field parties, and a small office force under the immediate direction of the chief draftsman of the dam and aqueduct department. The assistant engineers are Charles A. Bowman, Chester W. Smith, Moses J. Look and Harry J. Morrison.

The force employed upon this part of the work has varied from 17, at the beginning of the year, to 25, at the end of the year.

The main office of the department has been located in Pierce's Block, Clinton, and a branch office has been maintained at West Boylston.

NASHUA RESERVOIR.

Descriptive. In order that the subsequent statements with regard to the work done on the reservoir may be understood, I will give a brief description and statistics.

The reservoir is to be formed by constructing a masonry dam across a gorge through which the river flows just above Clinton, and by constructing dikes to the north and south of the main dam, to prevent the water from overflowing from the reservoir in other directions.

The reservoir will flood a very large area, containing a railroad, roads, houses, mills and other buildings, and it will be necessary to