1. OVERVIEW OF THE 1921 PUEBLO FLOOD; one of the deadliest in American history
J. David Rogers, Ph.D., P.E., P.G., F.ASCE, F.GSA
Professor & Karl F. Hasselmann Chair in Geological Engineering
Missouri University of Science & Technology
2017 AEG Annual Meeting
Colorado Springs

2. In 1921 Pueblo was the major commercial center of Colorado, with a population of 43,000 people. Approximately 18,000 men worked for one of the four railroads, two foundries, and casket, broom, mattress, macaroni, or coffee roasting factories. At the time one in every five Colorado jobs were in Pueblo and 55 percent of all products manufactured in Colorado came from the city.

3. The first hint of an impending flood on the Arkansas River in Pueblo, Colorado came at 6:30 PM on June 3, 1921, when an unknown person called and reported that the Arkansas River was flooding upstream because of a sudden cloudburst ten miles west of town.

4. The flood was very short lived, reaching a peak flow of 108,000 cfs around midnight, which only held for about 6 minutes. The total volume of water during the storms of June 2-5 was about 90,000 acre-feet in Pueblo.

5. The flood worsened when Fountain Creek also began to flood from down pours 30 miles north.

6. Slide Title
Stage record of the 1921 Pueblo Flood measured between June 2nd and 5th. Note the 20 foot rise between June 3rd and 4th

7. The flows of the two swollen rivers combined and peaked a little after midnight, inundating the city’s two principal rail yards and shops, shown here.

8. The flood peak occurred around midnight, while a Denver & Rio Grande Western train was parked in this station, filled with sleeping passengers.

9. The water depth was over 15 feet deep in some portions of the downtown area, drowning train passengers. About 300 people were killed within the city limits, but many more were believed to have perished downstream, where no warnings were possible.

10. All of the bridges over Fountain Creek were destroyed; however, the bridges over the Arkansas River and the rail yards remained.

11. The 1921 flood was one of the deadliest in America, exclusive of coastal areas, with close to 1500 people losing their lives, with about $20 million dollars in damages to Pueblo alone.

12. Railroad Levees
One of the greatest encumbrances to flood control were the railroad levees of the Rio Grande Western and the Santa Fe. Every effort was made to avoid re-routing these lines, if the need could be obviated some other way.

13. Channel scour around bridge abutments and supports
Aerial oblique view of the Arkansas river channel, which had been constrained by bridge crossings

14. 510 dwellings were simply washed away, 98 buildings wrecked, and 61 buildings washed off their foundations.

15. One of the biggest problems in the wake of the flood was the provision for potable water. The Colorado National Guard was called upon to provide security and sanitation, boiling drinking and cooking water

16. AFTERMATH OF THE 1921 PUEBLO FLOOD
J. David Rogers, Ph.D., P.E., P.G., F.ASCE, F.GSA
Professor & Karl F. Hasselmann Chair in Geological Engineering
Missouri University of Science & Technology
2017 AEG Annual Meeting
Colorado Springs

17. Arthur Morgan, founder of the Morgan Engineering Companies of Memphis, Tennessee and Dayton, Ohio
Soon after the floodwaters of June 3, 1921 subsided, Pueblo leaders realized the city needed more protection from the Arkansas River. They formed a committee of 200 to take on the various aspects of recovery, but whittled the flood control engineering panel down to just three men, so it wouldn't be unwieldy. They decided to hire Arthur Morgan to perform similar studies to those he had overseen for Dayton, Ohio after the flood of 1913.

18. Lumberjack in the Rockies
By his late teens he had a sense of being driven to do something more than usual, something above average, with his life, but he had no idea what that would be. His father encouraged him to become a surveyor, a craft with which he was already familiar.
Coercing a high school buddy, the pair set off an a “grand adventure,” floating down the Mississippi River on a large tree trunk. In a letter he described stopping at a store to wait for a man who was said to have work. Young men lounged around the porch, he wrote, "whittling their lives away, and are probably there yet. I happened to think, 'What if I should catch the same lethargy?' and we got up and left.“
Morgan ventured westward from Anoka, MN by himself, working his way to Colorado picking fruit, delivering goods, and mining coal. He purchased cent editions of Ruskin, Carlyle, Goethe, Emerson, and Kipling and tried selling them to miners, without any success.
His favorite job was at a lumber camp in the Rockies. But he soon learned the mill was sawing wood to be used to construct a gambling hall at a nearby mining camp. Being opposed to gambling – he quit and decided to return home.

19. The young surveyor
Morgan
During his sojourn to Colorado Morgan completed his formal education, taking a scattering of classes at the University of Colorado during a 6-week summer term. His poor eyesight and meager resources could not sustain him so, alone and broke, he returned home.
Morgan believed in the value of honest work, and scorned any scheme to profit one’s self through chicanery or cleverness. He vowed to do something that would “contribute to human well-being.“
Back in Minnesota he entered the surveying business with his father, as Morgan & Morgan rather than Morgan & Son.
In he achieved some measure of respect by preparing the Minnesota Water Control Code, whereby the state’s statutes for drainage control were formally established. The governor offered Morgan the post of state engineer, but he declined because his wife Urania, an osteopath, died suddenly, just four months after the birth of their first child, Ernest. He decided to leave Minnesota.

20. Supervising Drainage Engineer for the USDA
Morgan was one of four engineers hired by the Department of Agriculture's Office of Drainage Investigation in He soon became the Supervising Drainage Engineer.
The image at upper left shows him in 1908 with his "instrument men,” the same year that he contracted malaria.
While Morgan was working for the Department of Agriculture he received numerous inquiries about a proposal to sell drained swampland in the Florida Everglades.
When the Everglades surveying report fell into Morgan’s lap he refused to approve it for publication, leading to a congressional investigation and exposé of the fraudulent investment scheme.
Morgan
Morgan
Congressional panel formed to investigate the Everglades development scheme in 1909, hastened by Arthur Morgan (second from left, first row). He was 31.

21. The Morgan Engineering Company of Memphis
In 1910 Morgan left government to set up the Morgan Engineering Company in Memphis, strategically located halfway up the Mississippi.
The following year (1911), he married Lucy Griscom, a biology instructor on the Wellesley faculty, whose Quaker sense of mission would greatly influence Morgan’s life decisions. At 33, Morgan had finally completed his apprenticeship.
The firm specialized in consultations pertaining to water resources development, irrigation, and flood control for a wide range of clients, from railroads to government agencies.
He was able to attract many solid and capable civil engineers, to work on an array of challenging problems. In each case, Morgan would reward these men by making them partners in his young firm, a most unusual practice at that time.
This became the Memphis Morgan Engineering Company, which thrived for many years after Arthur Morgan departed.
Among the pioneering schemes the Morgan Engineering Co. developed was the 175-mile long bypass floodway extending southwestward from Cape Girardeau, MO for a congressional flood committee; and subsequently adopted by the Little River Drainage District in They excavated more than 100 million cubic yards of earth.

22. The 1913 Dayton Flood
4 rivers converge in Dayton within one mile of each other
The Dayton area averaged one major flood every decade
The Great Miami River watershed covers 3,937 square miles, 115 miles of channel; feeds into the Ohio River
23 March - Easter Sunday, rain begins falling
24 March - heavy rains. A 7 AM river reaches high stage for the year at 11.6 ft and continues to rise
25 March - 5:30 AM the Miami River reached unprecedented 100,000 cfs flow, streets begin flooding at 6 AM
26 March - flood waters reach their crest at 1:30 PM
Isohytes of March 23-27, 1913 storms, prepared by the Morgan Engineering Co.

23. The city had designed their levee systems to withstand a peak flow of 90,000 cfs
The flood waters reached a peak flow of 250,000 cfs, considered a 500-yr event at that time.

24. 10 square miles of Dayton were inundated
20,000 homes were destroyed in Ohio, most along the Great Miami River Valley. Hamilton was the hardest hit, with Dayton second.
700 people died in the storm event, including 467 in Ohio. Most of the casualties were elderly and children/infants
1400 horses and 2000 other domestic animals also died in the flood

25. Morgan moved from Memphis to Dayton, establishing the Morgan Engineering Co. of Dayton to carry out the work. He thrust himself into the research, design, and construction of a resilient flood control system, involving the entire watershed of the Great Miami River.
Arthur Morgan, CE
The Miami Conservancy District required legal pioneering to formulate the agency on a solid legal foundation that would withstand a flood of challenges from the affected communities. Morgan’s experience with drainage legislation west of the Mississippi proved invaluable.

26. In April 1922, the Colorado Legislature passed an act authorizing formation of the Pueblo Conservancy District to construct flood controls on the Arkansas and Dry Creek, and the district issued $4.5 million in bonds to pay for the construction ( ).

27. The “Rock Canyon Barrier Dam” was located about 7 miles upstream of Pueblo. It was a rubble masonry and earth-rockfill embankment dam about 33 feet high, with a volume of 200,000 yds3. It was 3,090 ft wide and the concrete spillway weir (grey) was up to 45 feet high. The structure was capable of storing about 19,500 acre-feet of water during a flood event (the reservoir pool was normally dry).

28. The barrier dam was constructed with three vertical notches, through which the Arkansas River and the Denver & Rio Grande Western Railroad passed. The plan was to limit the peak discharge to 100,000 cfs
The main spillway was built on Dakota Sandstone
The notch at was 70 ft wide and about 45 feet above the low water surface of the Arkansas River

29. Map showing the existing and the new, larger channel through downtown Pueblo proposed by Morgan’s firm

30. The inundation area followed the prehistoric limits of the Arkansas River flood plain
1,000,000 cubic yards of channel fill was required to construct the proposed protective levees along the re-routed river channel. 1,250,000 cubic yards of channel fill was placed beneath the new railroad yards that had to be re-located to make room for the channel. This fill served to elevate the yards to make them much safer from flood hazards.

31. The river channel through Pueblo was enlarged by constructing 15,000 lineal feet of concrete-faced embankments 32 feet high, which required one million cubic yards of earth, relocation of railroad tracks, and four new bridges. The new levees had 10-inch thick concrete slabs with 1.5:1 side slopes on the river side and 2:1 slopes on the protected side.

32. Concrete-Lined Trapezoidal Channel
The new channel was 12,600 feet long, intended to bypass the downtown business district. It was designed for a maximum capacity was 125,000 cfs, with a flow depth of 27 feet. The improvements were completed by June 1925.

33. Dry Creek
Fountain Creek
Map of the existing and proposed flood control channel through downtown Pueblo proposed by Morgan’s firm

34. A half century later, the Bureau of Reclamation considered replacing the 1925 rock barrier dam with the only massive head buttress dam in the USA, as part of their Fryingpan-Arkansas Project (later retrofitted with rolcrete).

35. Reclamation ended up settling on zoned wing embankments on either side of a massive head buttress spillway structure constructed in and christened Pueblo Dam.

36. Lowering of the channel levees in 2014
In 2014 the Pueblo Conservancy District lowered the Arkansas River Levee by 12 feet as part of a $15 million project to improve flood protection for downtown Pueblo, using the flood storage afforded by Pueblo Dam.