The first dam at Alouette Lake was designed and built between 1924 and 1928 by the British Columbia Electric Railway Company, later BC Hydro. However, the facility at the south end of the lake has never contained power generation equipment. Instead, the purpose of the dam was to raise water levels in Alouette Lake by fifty feet in the process of diverting them to power projects in the Stave Lake watershed. As part of the dam project, the BCER dug a one-kilometre tunnel between Alouette and Stave lakes underneath the north slope of Mount Crickmer. Water flows down this tunnel to power a turbine at the Stave Lake portal. The combined watershed of the Stave and Alouette then hosts two more generating stations at Stave Falls and Ruskin before its water falls into the Fraser River at Ruskin. The Alouette diversion was designed to produce 8.5 megawatts at its generating station on the western shore of Stave Lake  .
The construction of the dam at the south end of the new Alouette Reservoir began on March 22, 1924. The railway to the dam site was extended as a branch of the existing Abernethy and Lougheed Logging Company (Allco) railway, which served the company’s extensive timber holdings in Maple Ridge. The construction railway ran six-and-a-half kilometres between the Allco logging camp at the top of present 248thStreet and the lakehead. Materials and labour destined for the tunnel project would be taken by boat to the top of the lake to a point near the new intake. A workers’ camp, hosting between 100 and 200 men, existed at the rail-water break for the duration of the construction project – until the autumn of 1928. The right-of-way of the construction railway is now maintained as a private road by BC Hydro .
While the primary purpose of the dam was to divert water into BC Electric Railway power generating stations, the local population demanded the BCER become involved in flood prevention. The responsibility of the dam to prevent floods was a matter of public debate, and the management of water levels by the BCER came under attack during times of flood on the Alouette. Following unusually high water in 1941, popular opinion was that the reservoir levels were being kept too high—leaving too little room for expansion in times of heavy rain or snowmelt. In a 1942 letter published in the Gazette, BCER President W. G. Murrin reported that “the removal of the timber from the watershed has had the effect, here as elsewhere, of hastening the run-off, and this, therefore, has had a tendency towards aggravating flood conditions in the River”. He suggested that the dam bore credit for reducing the volatility of run-off from logged slopes:
“We may consider the greatest [run-off], in October, which resulted from an unusually heavy rainfall. […] thirteen and one-half inches [of rainfall] were recorded in thirteen days at Alouette Dam. To take care of this condition, we loaded our Alouette Plant to the limit, and also discharged water through the tunnel gate directly into Stave Lake, from October 9 to 20. This enabled us to divert 4,000 acre-feet of water per day, and to avoid a great flood down the Alouette River.” At the time, Murrin considered a total run-off through the Alouette River of more than 8000 acre-feet per day to qualify as “flood conditions”.
He cautioned, however, “We cannot generally allow the storage in the Lake to be depleted, as a measure of flood control, in anticipation of a possible future heavy run-off which may not always materialize.”  This indicated the company’s commitment to its first goal – producing electricity at its Stave River power generating complex.
The largest flood on record in the Alouette River valley occurred between November 3rd and 5th, 1955. Early in the morning on November 3rd, water in the south Alouette River had risen approximately four feet between midnight and 2:30am from a high autumn flow. Water had been released by the breaching of the dam, and a wide area below Yennadon was inundated. Although the greatest acreage was flooded in Pitt Meadows, property losses were greatest where the flows were faster and deeper, in the area around Maple Ridge Park . Five homes were damaged beyond repair by floodwater on 14th Avenue (232ndStreet) and 29thRoad (Dogwood Avenue). Of these, four were completely destroyed, belonging to the Harms, Warianko, Spalding, and Marshall families . 28 cattle were drowned in Pitt Polder after water overflowed the dyke at the Edge property . Although total municipal and private losses were first predicted to reach as high as $75,000 in 1955 dollars (roughly $650,000 2012 dollars), compensation assessments were revised down to $50,000 by November 24, and the province eventually refused to reimburse any more than 80% of damage claims lodged.
During this event, log jams at Maple Ridge Park and the 8th Avenue (224th St) bridge created swift and unpredictable currents. During high water on November 3rd and 4th, the volunteer fire department and Haney police attempted to rescue families trapped in the inundated area on 29th and 32nd roads. The town was later captivated by the rescue of Mrs. Warianko and her daughter Kathy, who – after several submersions in the fast-running water at Yennadon – climbed out onto a log jam and waited 12 hours for help to arrive. They were joined by several of their would-be rescuers whose skiffs had capsized in rough waters.  The Gazette wrote: “Kathy was swept under a brush pile despite the rescue line around her waist. Fortunately Constable Millhouse pulled her out and got her into the boat. Then the boat upset and apart from Constable Millhouse, who had the recue line in a half hitch around his waist, all occupants were swept about 300 feet downstream where they managed to climb on a log. Constable Millhouse is reported by other [sic] to have worked his way back up the life line about 300 yards in the extremely deep and fast water to reach and bring help to the marooned four whose plight was unknown to anybody at the time.”
As floodwaters receded, local residents used tractors to ferry food and supplies across washed-out roads. The Medical Health Officer at the Maple Ridge Health Center, W. J. Armstrong, posted a warning that all those affected should boil or chlorinate their well water, scrub down flooded cellars with disinfectant, and remove all contaminated foodstuffs . Oddities emerged soon after flooded areas had been drained, including a refrigerator recovered in Maple Ridge Park containing unbroken eggs  and the story of George Stanley Evans, age 79, who remained in his flooded home on 32nd road (132nd Avenue) for five days before seeking aid at a neighbour’s farm: Evans had been missed by rescue boats because his front lights were put out, and he reported having continued to sleep on his waterlogged bed .
Construction on the present dam began in 1983. The dam’s owners, now BC Hydro, intended to replace the 1926 structure with an earthquake-resistant design, which could also handle higher water volumes. At this time Colin Gurnsey, senior land supervisor for BC Hydro, considered a broader view of the dam’s purpose, summarizing neatly: “If we’re managing the river […] the costs of fixing up [flood] damages more than offset any costs for bringing the dam up to standards so [floods] can be controlled. We’ll have to spend the money one way or another eventually, so we might as well do it right. I guess that’s the argument that won out.” 
Carpenter, E. E. “Launching of Alouette Development Continues Company’s Power Programme”. The BC Electric Employee’s Magazine, (1924, April). p. 4-8.Carpenter, E. E. “Alouette-Stave Development Well Under Way”. The BC Electric Employee’s Magazine, (1924, June.) p. 7-8.Carpenter, E. E. “Alouette-Stave Development Well Under Way”. The BC Electric Employee’s Magazine, (1924, June.) p. 7-8.“Alouette Rivers Controllable?”. Gazette, (1951, January 5). p. 2.“Alouette Dam Improves Flood Control.” Gazette, (1942, March 15).“Alouette Dam Improves Flood Control”. Gazette, (1942, March 15).“Alouette River Flood Damage Will Not Exceed $100,000”. Gazette¸(1955, November 10). p.1.“Dam’s Collapse Kept Secret”. Vancouver Sun, (1955, December 12). “Drastic Loss in District Caused by Flooding of Alouette Rivers”. Gazette, (1955, November 10). p.1.“Reeves to Meet with B.C. Premier”. Gazette, (1955, November 24). p.1.Alouette River Flood Damage Will Not Exceed $100,000”. Gazette.“Mr. & Mrs. W. Harms Lose Everything in Flood”. Gazette, (1955, November 10). p.7.“Flood, Fires Destroy Ten Homes in District in Past Two Weeks”. Gazette, (1955, November 24), p.1.“28 Cattle Drowned in Pitt Polder Area”. Gazette, (1955, November 10). p.8.“Reeves to Meet with B.C. Premier”. Gazette.“Drastic Loss in District Caused by Flooding of Alouette Rivers”. Gazette.“Residents Advised to Guard Against Contamination”. Gazette, (1955, November 10). s.2. p.1.“Refrigerator Lands in Maple Ridge Park”. Gazette, (1955, November 10). S.2. p.1.“Flooding South Alouette Strands Resident 5 Days”. Gazette, (1955, November 17). p.7.McKave, Marianne. “57-year-old dam gets grand tour before replacement work begins.” Gazette, (1983, March 2).