Whitney Dam consists of a 1,400 foot long earth embankment and a 120 foot wide grassed emergency spillway. The outlet consists of a concrete riser with 7.5 foot long weirs on each side and a 30-inch reinforced concrete outlet pipe discharging into Patten Brook at the toe of dam. Maximum height of dam is 52 feet with a maximum storage capacity of 1,960 acre-feet. Based on the visual inspection, Whitney dam appears to be in good condition. Only one small cedar tree is growing on the embankment and there is evidence of recreational vehicles climbing the embankment in three locations. The rodent screen on one foundation drain outlet is partially missing and the slide gate stem at the principal spillway outlet is bent and appears to be inoperative. Calculations by the Soil Conservation Service show a peak inflow of 6,500 cfs. and a peak outflow of 1,930 cfs. with a maximum water surface elevation 2.0 feet below the crest of dam, which was used as the test flood.

Ellithorpe Dam consists of a 4,250 foot long earth embankment and a 200 foot wide grassed emergency spillway. The outlet consists of a concrete riser with 23 foot long weirs and a 48-inch reinforced concrete outlet pipe discharging to Middle River at the toe of dam. Based on the visual inspection, Ellithorpe Dam appears to be in good condition. There are several recreational vehicles paths on the slopes with some erosion taking place. Also, there are numerous rodent burrows on the upstream slope. Maintenance practices at Ellithorpe Dam appear to be good. Based on Corps of Engineers guidelines, the PMF was calculated to be 16,900 cfs inflow, with the outflow 10,800 cfs at an elevation of 591.6, which is 0.6 feet over the top of dam. This flow was used as the test flood.

The dam, completed in 1961, is an earth embankment approximately 390 feet in length with an emergency spillway at its left with end. It is a flood control project approximately 28.5 feet in height and capable of impounding approximately 520 acre-feet of water. The principal spillway is a drop inlet type structure consisting of a reinforced concrete riser with a 24 inch diameter reinforced concrete outlet pipe through the dam. The grass-bottomed emergency spillway channel is cut into natural ground at the left end of the dam and has a crest length of 125 feet. The top and slopes of the dam are grass covered, with a filter drain at the toe of the downstream slope. Based upon the visual inspection and past performance, the dam is judged to be in good condition. No evidence of instability was observed in the project. There are some remedial measures, such as filling of large holes in the 'waste areas' adjacent to the dam, reestablishment of greasy vegetation in the vehicle tracks on the top of the dam, and institution of a biennial inspection program, which require attention. The spillway capacity with the pond level to the top of the dam is 4700 cfs, which is equivalent to 1300% of the routed test flood outflow.

The dam is comprised of an earthen embankment on the upstream side of a near-vertical rubble stone masonry wall, which is approximately 340 feet in length and rises approximately 37 feet above the original streambed elevation of the Mill River. The upstream earthen embankment is approximately 20 feet wide at the dam crest and has an upstream slope with a maximum inclination of 3 horizontal to 1 vertical. The right portion of the spillway is a concrete compounded circular crest with a sloped downstream face. The left portion of the spillway is a side channel concrete ogee section. The area below the dam is developed with industrial buildings, a high school, and residential structures. Based upon the visual inspection at the site and past performance of the dam, the dam is judged to be in good condition. No evidence was observed of structural instability in the earthen embankment or the masonry wall. The condition of both the embankment and wall appears to be good. There are some areas requiring attention. Based upon our hydraulics computations, the spillway capacity is 9700 cubic feet per second, which is equivalent to approximately 21 percent of the Test Flood. Peak inflow to the reservoir is 48,600 cubic feet per second; peak outflow (Test Flood) is 46,500 cubic feet per second with the dam overtopped 4.4 feet.