Rio in Southside

The Friends of the Rio was founded primarily to oppose to the United States Army Corps of Engineers (USACE) plan to relocate the Rio de Flag underground in massive cement boxed culverts, an outdated and expensive method of flood control. The Friends of the Rio still finds that a natural channel design to be a more cost-effective approach and allows the Rio de Flag to remain as a valuable community asset. View our page specifically on Flood Control for more information. 




According to Stone Landmarks: Flagstaff’s Geology and Historic Building Stones (By Marie D. Jackson, 1999), the Rio was rerouted through the low-income ethnic Southside Neighborhood of Flagstaff to prevent flooding in the new P.J. Brannen’s upper-middle-class subdivision (a subdivision that was approved in 1894).

A 2800 ft shallow and narrow trench was built southeast from Cottage Ave to the head of a small existing tributary near O’Leary and Ashurst St (Figure 1). The new channel was said to have intensified residential flooding 1896-1938 in Downtown, Southside, and even still today as the channel remains very narrow.

Figure 1 –


The Southside Neighborhood is a historic area home to many underprivileged minority peoples, a great number of whom came to Flagstaff during the booming lumber industry in the early 1900s. The Southside has faced the dangers of flooding since the late 1800s and remains in a Federal Emergency Management Agency (FEMA) designated floodplain today.


“The flood zone makes it more expensive to purchase home insurance, to make repairs, and to build affordable housing— but once the river is re-channeled to protect against floods, the land and housing in Southside will increase in value, and possibly lead to gentrification and removal of longtime residents who have doggedly held onto homes built by their parents and grandparents, but which are now in need of repair and renovation.” – Ricardo Guthrie, PhD  (Ricardo is the Director and Associate Professor of Ethnic Studies at Northern Arizona University).



Children in the Southside play near the Rio in the 1960’s (Courtesy of MNA Archives)

Friends of the Rio de Flag received an Environmental Protection Agency (EPA) Environmental Justice Small grant in 2017 to lead a collaborative, community-based education and river planning initiative focused on Flagstaff’s underserved Southside Neighborhood. This project seeks to engage the Southside Neighborhood in planning for the future of its river.

At the same time, the City of Flagstaff is working on completion of a Southside Neighborhood Plan. The City will be hosting public meetings to collect neighborhood feedback in order to plan for the future of the neighborhood. Friends of the Rio has partnered with the City in order to work together on the river-specific portion of community engagement for the Southside Neighborhood Plan.

Currently, the Rio Project has a Benefit-Cost-Ratio (BCR) of 0.85, whereas a majority of projects that receive federal funding have a BCR of 2.0 or even 3.0 if not greater. Unless the City is able to reach a greater benefit-cost-ratio, the Rio Project will remain dead in the water without funding.

The Flagstaff community must look towards local funding options in order to complete the Rio Project.


Why is Flood Control Urgent?*

  1. The community is at risk of catastrophic flood, which is a threat to life, health, and safety.
  2. Estimated $916M in Flood Damage and over 1,500 structures impacted
  3. The floodplain regulations and mandatory flood insurance make the area expensive to renovate and to own a home.

Flooding in Continental Estates (East Flagstaff) in 1993. It was a “25-year” flood.

The City is currently completing an updated Southside Neighborhood Plan addressing such issues as affordability, parking, and flood control. The Rio de Flag in Southside is a catch-22 situation. The threat of flooding and the expensive of flood insurance must be dealt with, however, when the floodplain is removed there is the risk of increased change in the composition of the neighborhood. Please join us as we work towards understanding the specific implications of a flood control project and threats faced by the Southside residents.

Upcoming Neighborhood Planning Meetings

July 24th :: 4:30 – 9pm at South Beaver School

July 26th ::  4:30 – 9pm at South Beaver School

August 18th :: Stormwater meeting from 12-3pm at the Murdoch Center. At this meeting. The plan for this meeting is to get into the nitty-gritty of flood control for the Southside residents.


Additional Resources

  1. Presentation: The (Mis) Management of the Rio de Flag; Food Justice and Social Vulnerabilities of the Southside Neighborhood (Muchna, 2018).
  2. Document: Southside Plan (2005) – Neighborhood Plan that was created but not adopted into policy by the Flagstaff City Council.
  3. Brochure: Rio de Flag in Southside Neighborhood – A quad-fold brochure created to help info residents on the connection between the Rio de Flag and Southside.



* Duval, James (2017). Flagstaff City Council Meeting, January 16th, 2018. Retrieved from