9 things you should know about the Truckee River flood control project

The Army Corp of Engineers has released its Draft General Re-evaluation Report and draft environmental statement for the Truckee Meadows flood control project. The Corps held a public meeting about the plan last week and will hold a second and final meeting Wednesday, June 19, at the Sparks City Council Chamber.

The deadline for public comment is July 7. The Corps’ goal is to submit a final plan to Congress by the end of the year.

The report is a 211-page PDF file, which does not include the appendices. The EIS is in two volumes, one 405 pages long and the other 379 pages. Here are some highlights:

1. The community coalition plan put together by the Truckee River Flood Management Project “did not result in a plan that the Corps could recommend.” Instead, the Corps has studied modifications to its own plan that Congress approved in 1988.
2. The plan “efficiently reduces flood damages in high-value commercial and industrial areas near the Truckee River, including the Reno-Tahoe International Airport, by containing flood flows with levees and floodwalls, enlarging the existing channel with floodplain terracing, and by detaining peak flows in a designated overflow area . . . near the mouth of Steamboat Creek . . . largely occupied by the Nevada Agricultural Experiment Station.” See page 154 of the report PDF file for a map.
3. The plan does not include any work in downtown Reno because it was not economically feasible.
4. The Corps has concluded that a plan for the 1:50 event (one that would have a one in 50 chance of occurring in any year) would provide the “greatest net economic benefits” and that a plan for a 1:100 event would not. Therefore, this plan is for the lower level (1:50) of flooding. (The 1997 flood was deemed a 1:117 flood, or one that would have a one in 117 chance of occurring in any year).
5. Modeling found that the plan would “induce flooding” in the Steamboat Creek/UNR Farms area; that is, the100-year flood elevation would increase as much as 0.6 foot there. About 900 residences in this area are already in the 100-year floodplain. The increased flood elevation would put about 175 additional residences in the 100-year floodplain, but they should still be above flood level. (Note: The owners probably would have to start buying flood insurance or pay higher rates if they already buy it.) The flood elevation would “affect” 22 additional residences (which presumably means the induced flooding would put them both in the floodplain and below the flood level, with similar flood insurance effects). See pages 155, 159 and 160 of the report PDF.
6. Modeling found that the 100-year flood level on the North Truckee Drain just north of I-80 would increase by 0.5-1 foot.
7. The Corps did not find that doing anything about this induced flooding would be “economically justified” for federal funding. However, the National Flood Insurance Program would require the community to keep structures from being impacted by the plan. The Corps report recommends raising structures in the UNR Farms area and installing a pump station at the North Truckee Drain. See page 162 of the report PDF.
8. Some recreation facilities are included in the plan. Provision for fish passage was studied but not included.
9. The estimated cost of the plan is $260,660,000 with the federal government paying $163,774,000 and the community paying $96,887,000. The Truckee River Flood Management Authority would have an additional $195,000,000 as the estimated minimum cost to comply with the National Flood Insurance Program requirements for avoiding the induced flooding caused by the plan. The estimated average annual maintenance costs (also paid locally) would be $429,000. See details on page 13 of the report PDF.

According to a Corps handout, the TRFMA “is pursuing options to further decrease the community’s flood risk beyond what is provided by the proposed plan.”

Washoe County residents have been paying a one-eighth cent sales tax for flood control since 1999. Expenditures by the TRFMA so far have been for staff, planning, outreach, land purchases along the Truckee River in 2006, downriver restoration projects and the Reno-Sparks Indian Colony levee.