• Bull Run Lake - origin of our drinking water
  • Aerial view of Bull Run Lake and clear cuts
  • Construction of Reservoir 5 at Mount Tabor 1910
  • Reservoir 1 "Thumbelina" at Mount Tabor looking south
  • Construction of Reservoir 6 at Mount Tabor 1910
  • Reservoir 3 at Washington Park 2010
  • Bull Run Lake - Frank Dodge Island
  • Reservoirs 3&4 at Washington Park 1900

Ernest L. Ransome-Portland’s Open Reservoir Rebar Construction

During the Historic Landmark Commission and Portland City Council hearings, the Portland Water Bureau testified without evidence that open reservoirs’ construction was built using rebar placed at +10 foot intervals. This statement makes no sense from an engineering and construction basis. Portland Water Bureau provided misleading and incorrect testimony trying to convince Council and Landmark Commission there was an open reservoir construction defect. There are no defects. The Washington Park soil drainage and pump system, along with de-watering processes provided stabilization improvements for the last 100 years. Ironically, when Portland Water Bureau was asked about the cement and rebar construction defects that lead to 3200 cracks in the recently built $130 million 2014 Powell Butte Reservoir 2 there was no answer; other than they were working on it.


We have proven through photos and diagrams the open reservoirs were built to consistent open reservoir rebar specifications as shown in the historic construction images. Portland’s open reservoirs at Mount Tabor and Washington Park were designed, engineered, and built by Ernest L. Ransome the “master” and “father of reinforced concrete”. The open reservoirs have provided safe and healthy water for over 100 years because of their advanced construction workmanship and design. Reinforcing steel (rebar below) was placed in 1 foot to 2 foot increments as shown by reservoir construction photo. The approximate 1 foot rebar increment was critical to the wall and sloping areas. The rebar increment addressed the 20° (degrees) of slope on the reservoir walls and other vertical areas. The Ransome buildings at Stanford University were the only structures to withstand the Great 1906 San Francisco Peninsula earthquakes clearly demonstrating innovative and superior construction and engineering.