[3] The dam continues to be fully functional for hydroelectric generation, as one of the drinking water sources to Juneau city and for aquaculture and fishing.

The dam (marked as Juneau B-2 in USGS maps) is located at the terminus of the tram-way that was built specifically by the Alaska Gastineau Mining Co.

However, a 3 miles (4.8 km) long road had been built by AEL&P to the upper powerhouse at the base of the Salmon Creek Dam, which has since been de-commissioned.

The stream bed has large gravel and bedrock substrata and its gradient decreases downstream of the dam.

Basically, an arch dam is a structure that curves upstream and the water pressure is transferred either directly to the valley sides or indirectly through concrete abutments.

This theory led to the development of the "constant-angle" (or variable radius) arch dam, which was also thinner in design.

[16] However, AEL&P gives design credit to their then Chief Engineer Harry L. Wallenberg for the Salmon Creek Dam.

Lars R. Jorgenson who had conceived this concept had proved that the most economic design of the dam was obtained with an optimum opening angle of 133.6°, with the least quantity of concrete.

[12] An ice pressure of 10 tons per square foot (500 kPa) was considered based on the rim conditions of the reservoir and the design was also checked for an ice pressure of 20 tons per square foot (1,000 kPa); in the latter case the safety factor in concrete under resultant compression values was considered to be 5 and safe.

A steel outlet pipe of 4 feet (1.2 m) diameter was proposed to be embedded in the mid base of the dam as a spillway.

The reservoir water spreads to an area of 192 acres (78 ha), while the catchment drained is 7.5 square miles (19 km2).

An article from the National Science Foundation's SimScience project notes the following:[1] The upstream bulging served to offset the undercutting by the stronger curved lower arches near the abutments while the pronounced downstream toe reduced the tensile stresses at the upstream heel.

The aggregates were mixed in designed proportions with cement and with a small admixture of lime to manufacture concrete for placing on the dam.

The first power station, the upper powerhouse titled 'Powerhouse 2', was located 1 mile (1.6 km) below the dam and had an installation of two units of 1.5 MW capacity each operating under a hydraulic head of 600 feet (180 m).

Near Powerhouse 1 on the shore, office buildings, machine shops, saw mills, canteen and housing facilities for staff were also built.

[5] Salmon Creek reservoir is a secondary source of drinking water which is provided in conjunction with Alaska Electric Light and Power Company (AEL&P).

However, this source is subject to seasonal high turbidity and also interruptions due to the annual maintenance of the generator units.

The water resources are generally pollution-free and quality is monitored and tested every month to check for drinking-water standards set by the EPA and Alaska Department of Environmental Conservation (ADEC).

[20][21] In 1880, the Salmon Creek was named by Richard Harris and Joe Juneau (during their first visit to the area for gold prospecting).