"After months of darkness light has come to guide the weary traveler home. And we have found that just for pay, the dreary night has turned to day. Oh, that our trials might now be over, Oh, that our pastures might be clover. Henceforth and forever this city shall be lit by its own electricity. And in the years to come we'll say, that was for us a glorious day, When first the streets and stores at night used arc and incandescent light."

F. B. Lambert had an idea that the event was important. His poem appeared in the Rochester Post to commemorate Rochester's first public utility: an electric lighting plant. Learn about RPU's humble beginnings and how it grew into one of Minnesota's largest utilities.

The History of Rochester Public Utilities

1885 – 1915: The New Lights

In the early 1890s, Rochester's population numbered just several thousand. Kerosene and oil street lamps had lighted the city’s main thoroughfares since the mid 1870s. But times were changing and the city was beginning to grow. By the late 1880s the City Council had seen and heard of the electrical power generated by municipally owned plants. Motivated by the need for safely lit streets and reliable electrical service, in 1892 the City Council (after several rancorous meetings) sanctioned the construction of Rochester's first public utility: an electric lighting plant measuring just 27 by 72 feet. After this plant burned down in October 1915, the dim working conditions and rough floor boards were replaced by the new plant construction on North Broadway.

The generator was turned by a belt from the enormous flywheel. To start the 16-ton flywheel for the steam engine, plant workers sometimes had to insert a long heavy bar into a hole on the wheel and manually crank the wheel to a position where the steam engine drive arm could move it.

1894 – Rochester’s First Municipally Owned Power Plant Generates Electricity

On the gently snowing evening of March 14, 1894, Western Electric construction foreman A.C. Sprout switched on the current for lamps on the west circuit; moments later he lighted the lamps on Broadway. Spectators gathered for hours to catch a glimpse of the events inside the plant. Rochester's first municipally owned power plant generated electricity on March 14, 1894, but did not operate full-time until May when the city's contract with a private lighting company expired. By the turn of the century, the fire department had vacated the building and the Light Plant occupied the space.

1887 – City's First Water Service

Not attracting as much attention as the electric plant opening was the struggle the water works faced in the 1890s. The water company had difficulty showing a profit to the stockholders while still delivering water, main extensions, and service to the swiftly growing city. The water company was subject to disasters that cost time and money to recoup. When the pump house flooded during a 1903 flood, an engineer jumped into the water that was up to his head and adjusted the pump valves with his feet. During another flood in 1908, the whole water works plant was submerged and the boilers extinguished. A sprinkler truck kept Saint Mary's Hospital supplied from the well owned by Schuster Brewery. In 1910 the water company drilled its first deep well, about 418 feet deep.

Dr. William Worrall Mayo took a strong leadership role in developing Rochester's water and electric services. An outspoken advocate of municipal ownership of utilities, Mayo served a term as Mayor (1882 – 1883) and held a seat on the City Council.

1916 - 1949: New Utilities and Responsibilities

By 1915, city growth indicated the water and electric service would face enormous demands. Rochester had grown nearly 15 percent from 1900 to 1910. 1910 to 1920 was the explosion in growth decade; the city grew from 7,844 to 13,722, a 75 percent growth rate! As a result, city leaders were looking at water and electric service changes for Rochester. The Utility Board, formed in 1904, would study building a new and more reliable light plant in 1915 after the Third Street Southwest plant burned on Oct. 31, 1915.

The hydroelectric dam and powerhouse were under construction July 1, 1918. The North Broadway Plant and new hydro plant could produce enough electricity, in that era, to meet the needs for a city of 60,000 residents. The Lake Zumbro facility has used water-driven generators to supply electricity for Rochester consumers since the powerhouse was placed in service on Nov. 7, 1919. In 1961, concrete workers refurbished the structure and remote controls were developed for plant operations.

The water department was created in 1916 following a May 25 bond issue to purchase a private water company. The Utility Board and City Council faced four service problems for the water department during the 1920s: water supply and storage, pumping capability, metering usage, and financing water main extensions. In 1924 and 1925, four static or artesian wells were bored on water department grounds near the Fourth Street Southeast pumping station. The only water storage was the Saint Mary’s Park standpipe (built in 1887) and 500,000-gallon underground reservoir (built in 1916 – 1917) near the waterworks. In 1924, a 200,000-gallon concrete water tower was completed on "College Hill" next to Saint Mary’s Hospital.

As the water department entered the 1930s, its pumping and storage problems that had seemed daunting ten years before found remedies to deal with the city’s growth. Rochester soon would have more than two million gallons of storage and a pumping capacity of 7,100 gallons per minute. Fire protection remained a vital concern, but 378 hydrants on the 38 miles of water main provided a far better safety net than the 208 fire plugs on the 17.5 miles of main when the city bought the system.

The 200,000-gallon concrete tower, built near College Street (Fourth Street Southwest) in Saint Mary’s Park still furnishes water pressure and a reserve supply for the high-level system in southwest Rochester.

Eelectric - and gasoline-powered pumping machinery improved efficiency at the Fourth Street Southeast Water Works after it was installed in 1924. The eight-cylinder engine provided Rochester's first reliable auxiliary water pump when storms would interrupt electricity to the main pumping unit.

In 1928, the school system approached the Utility Board with a steam heating proposal to run a steam line from the North Broadway Plant. The steam used to run those turbines could be further used by ducting it to the school for heating and driving vent fans. Using the plant for these two purposes prompted the label "co-generating facility." Until maintenance and other costs reduced the net return years later, the Utility Board found willing customers in the central district for this relatively inexpensive and odor-free heat source. The steam system was operated until April 1986. Approximately 100 customers were on the steam service.

In 1937, People's Cooperative Power Association, a rural cooperative, negotiated an agreement to buy wholesale power from the North Broadway Plant. The agreement was approved by a representative of the Rural Electrification Administration from Washington, D.C., and all parties were pleased by the arrangement that was to last almost 20 years. By March 1949, the Co-op took 24 percent of the total annual kilowatt-hours of the electric department, while Rochester residential consumers used 28 percent. As the Co-op needed more power to serve its growing customer demand, it engaged Interstate Power Company in 1952 for that wholesale supplement and in 1956 the agreement between Rochester and the Co-op expired. The Nov. 21, 1956, Post-Bulletin recorded this account of the relationship: "The arrangement between People's Cooperative Power and the City of Rochester had been an excellent example of cooperation between a rural electric system and a municipally owned generating system. In referring to the harmonious relations between the two organizations, [People's Co-op] Manager Ray Krofchalk commented, 'We will always be grateful to the City of Rochester for the way it stepped in to meet our needs for wholesale power...when it meant the difference between success and failure of our efforts.'"

When the Park Board developed plans for the Silver Lake Park in the 1930s, the Utility Board requested that some of that property be used for a new generating plant. Construction began in 1947 with a groundbreaking ceremony. The new Silver Lake Plant went on-line in April of 1949. The 7500-kW unit was powered by a 90,000 lb./hour steam boiler and necessary equipment.

1950 – Present

In 1951, after the worst flooding since 1908, the Park Department gave the Utility Board control of the Silver Lake Dam. The Fourth Street Northeast dam pooled water for the North Broadway plant, and the Silver Lake Dam pooled water for the Silver Lake Plant.

Silver Lake unit three was installed in 1962; unit two (1953) and unit one (1949) are the smaller generating units beyond number three.

In 1975, a 30-megawatt gas turbine unit was installed to supplement power during peak demand at the Cascade Creek substation, located between Seventh Street Northwest and Highway 14 West.

In 1978, Rochester joined the Southern Minnesota Municipal Power Agency (SMMPA) with Council approval. "Organizing and joining SMMPA was probably the most fundamental change that this utility has ever seen," commented John Miner, RPU General Manager from 1983 – 1986. "There has been and will continue to be spirited debate among its members about how well SMMPA does its job," he acknowledged, "but I believe, at this point, that SMMPA has accomplished what the founders intended." SMMPA allows its member cities to pool their electric power and meet their communities’ energy needs. Initially, RPU was a full-requirements member with SMMPA controlling all of Rochester's electric power. Today, RPU is a partial-requirements member of SMMPA and retains control over its own generating units.

With the introduction of the Clean Air Act in 1976, issues of power plant emissions, PCBs, and water quality were addressed by RPU and other utilities. Precipitators (to reduce airborne emissions) and cooling towers (to control water emissions) were costly additions. RPU's commitment to the environment did not end with costly construction projects. It has employed a full-time environmental regulations specialist since the late 1970s and continues to monitor all plant emissions. Since the mid-1980s, many changes have occurred at RPU.

Projected reduction amounts:

Both the water and electric departments made efforts to place public service as their first priority. Yet one enduring feature of municipal ownership's responsibility to the public surfaced in the 1930s and continues today: the utilities return revenue to the city. In 2001, for example, the Electric and Water Departments returned $6,837,000 to the city of Rochester.

  • 1988 – Completion of Service Center construction.
  • 1990 – Conversion of RPU's transmission system from 115,000 volts to 161,000 volts begins. The project was completed in 2002.
  • 1993 – RPU joined the Mid-Continent Area Power Pool (MAPP), further ensuring Rochester's power requirements will be fulfilled into the next century.
  • 1994 – RPU completes 100 years of electrical service.
  • 1995 – RPU signs a Participation Sales Agreement with the Minnesota Municipal Power Agency (MMPA) for the output of the Silver Lake Plant.
  • 1996 – Walt Lorber named as Acting General Manager during an internal reorganization. Larry Koshire became the new General Manager in 1997.
  • 1998 – City of Rochester experiences first total blackout in 20 years as storms damage major transmission lines in the area.
  • 1999 – RPU Board elects Contracted Rate of Delivery (CROD) status with SMMPA.
  • 1999 – Board approves a new combustion turbine.
  • 2000 – The Board and Council approve the sale of electric revenue bonds to pay for the new turbine and other electric system improvements. This is RPU’s first bond
  • 2001 – The Council/Board approves the sale of steam to the Mayo Clinic.
  • 2002 – A new combustion turbine, similar to jet engines that power 747s, goes online in May.
  • 2008 – The ERP involves improving the 55-megawatt unit four generator by adding a scrubber and baghouse system for treating flue gas emissions is completed.
    • Sulfur Dioxide – up to 85 percent
    • Nitrogen Oxides – up to 60 percent
    • Mercury – up to 80 to 90 percent
    • Particulate Matter – a significant reduction
    • Dedication of the Cascade Creek Gas Turbine, May 2002
  • 2012 – The RPU Board approved a resolution directing staff to develop and execute a plan to decommission the Silver Lake Plant (SLP) by December 31, 2015 or sooner; ending all coal burning and electric generation at SLP.
  • 2013 – The 3.3 million gallon Saint Mary’s Reservoir was completed. (photo 004) The groundbreaking was held for the CapX2020 transmission project Hampton-Rochester-LaCrosse (WI) line. (photo 0025- caption- RPU staff and Board President attend the CapX2020 groundbreaking event.)
  • 2014 – The 2 million gallon 50th Avenue Hydropillar was completed. (photo DJI 0015) The first 161 kilovolt (kV) transmission line for the Hampton-Rochester-LaCrosse (WI) part of the CapX2020 transmission project was energized. (photo 0225- caption- A helicopter was used to string parts of the Capx2020 line.)
  • 2015 – The RPU Board approved the purchase of five Wartsila reciprocating engine generators for an amount not to exceed $22.5 million.
  • 2016 – The second 161 kilovolt (kV) transmission line for the Hampton-Rochester-LaCrosse (WI) part of the CapX2020 transmission project was energized.
    • The 500,000 gallon St. Bridget Water Tower was completed. (photo 4903)
    • The RPU Board approved the construction bid to build the Westside Energy Station, which will house the five Wartsila reciprocating engine generators approved in 2015 by the RPU Board.
  • 2019 – The RPU Board reviewed the RPU Resource Plan and voted unanimously to direct staff to further pursue two 100% renewable scenarios, one including a peaking generator and one involving battery storage for serving RPU customers after 2030.
  • 2019 –  RPU held an open house and offered public tours of the Lake Zumbro Dam as part of the 100 Year Anniversary of the facility.