Fall Creek project data

Dam length 5,100 ft 1,554.5 m
Height 205 ft 54.9 m
Elevation (NGVD*) 839 ft 255.7 m
Lake length 6.8 mi 10.9 km
Area when full 1,820 ac 736.5 ha
*National Geodetic Vertical Datum

Contact us about Fall Creek:
General: 541-684-4300
Recreation: 541-942-5631

Email us about Fall Creek

Fall Creek pamphlet

Fall Creek Dam & Reservoir

Fall Creek Dam and Lake

Link to PDF version of Fall Creek Dam map graphic

Project Description:

Fall Creek Dam is located on Fall Creek, a major tributary to the Middle Fork Willamette River, one mile upstream of Unity, Oregon and 25 miles upstream of Eugene and Springfield, Oregon. Fall Creek Dam is a 205-foot tall, 5,050-foot long rockfill earthen embankment dam with a concrete spillway, two spillway gates, and a regulating outlet. Fall Creek Dam is owned, operated, and maintained by the Portland District of the U.S. Army Corps of Engineers (USACE). Construction of the dam began in 1964 and was completed in 1965.  Fall Creek Dam is part of a system of 13 multi-purpose dams in the Willamette Valley with the primary purpose of flood risk management and secondary purposes of recreation, irrigation, municipal and industrial water supply, fish and wildlife, conservation, water quality, and hydropower. Collectively, this system of dams is referred to as the Willamette Valley Project (WVP). Fall Creek Dam is one of four WVP dams that does not include a powerhouse.

During the winter months, the Willamette Valley Project reservoirs are maintained at their lowest elevations to allow for the temporary storage of rain and snow melt. When managing high flow events, the outflow from the system of dams is coordinated to reduce peak flows and river stages at downstream locations. In spring, USACE begins to fill the reservoirs, increasing the amount stored for conservation purposes and reducing the amount of storage available for flood risk management.  During summer, stored water is used for recreation on the reservoirs, and some stored water is released in the river downstream to improve water quality, support fish and wildlife habitat, and provide water for 
irrigation and municipal uses. During dry summer months, flows into the reservoirs are generally less than flows needed to meet minimum flow objectives, causing reservoir levels to drop. In fall, stored water remaining in the reservoir is drawn down to minimum levels in preparation for the flood season. Fall Creek Dam is located about 70 miles east of the Cascadia Subduction Zone, a megathrust fault along the Oregon Coast. The Cascadia Subduction Zone is capable of producing very large, long duration earthquakes. The last Cascadia Subduction Zone earthquake occurred in the year 1700.    

Risk Characterization: 

High.  USACE completed a routine risk assessment for the Fall Creek Dam in October 2014 that characterizes the risk associated with the dam to be High.  USACE performs risk assessments as part of an ongoing dam safety program and to assist in the prioritization of investment for aging infrastructure.  The risk assessments evaluate the life safety risks associated with the dams to determine if risk reduction actions are needed and, if so, what actions should be taken.  The assessment considers a wide range of hazard scenarios from the most likely to the most extreme and unlikely. The 2014 assessment concluded that the risk at Fall Creek Dam is driven by the high population downstream two possible, but very unlikely events: 1) an extreme earthquake occurring at the same time reservoir elevations are the highest or 2) an extreme flood event that fills the reservoir at a rate faster than the dam can pass water through the spillway.  

An extreme earthquake could cause the rockfill earthen dam to settle and crack, resulting in water overtopping and flowing through the dam. It is difficult to predict the exact amount of settlement and cracking that could occur to the dam as a result of such an earthquake. The speed and depth of water flowing over and through the damaged dam could erode the soil and rock that forms the dam and cause significant flooding downstream. The strong shaking from an earthquake could also damage the spillway’s concrete structure and gates. The assessment also determined that fallen trees and woody debris floating in the reservoir could partially block the spillway gates during an extreme and unlikely rainfall event. The partial blockage of the spillway gates from the debris could reduce or prevent passage of flow through the dam, which would cause the reservoir to rise above and flow over the top of the embankment dam. As water flows over the top of the dam, the speed and depth of the water could erode the soil and rock that forms the dam. Because Fall Creek Dam is located upstream of Eugene and Springfield, Oregon, there is potential for devastating flooding to affect large downstream populations in urban areas and surrounding suburbs, as well as rural communities in the floodplain.  


USACE is confident that the Willamette Valley dams are well-built, well-maintained, and will continue to significantly reduce flood risks for the region. However, the dams cannot eliminate potential for flooding. Even with the presence of the Willamette Valley dams, extreme rainfall and snowmelt events may result in flooding in areas downstream of dams.  Flooding can be caused by high flows resulting from unregulated portions of the watershed and/or high flow that must be passed through the dam outlets and spillways when reservoir storage capacities are exceeded.  

Risk Management Measures:

The likelihood is very low for an extreme earthquake or extreme flood resulting in a breach of the dam to occur, but the potential impacts of a dam failure are very high due to the large downstream population. Therefore, Fall Creek Dam will enter an advanced risk assessment called an Issues Evaluation Study (IES) starting in 2021 to further evaluate the dam’s performance during extreme seismic and flood events. The study will also determine whether short-term targeted measures (called Interim Risk Reduction Measures) or long-term modifications are necessary to reduce the risk.  USACE regularly conducts routine inspections of its dams and Fall Creek Dam is equipped with instrumentation to monitor dam performance and seismic activity. Post-earthquake procedures are in place to inspect and evaluate earthquake damages and USACE conducts routine dam safety exercises with local Emergency Managers and first responders. Fall Creek Dam’s Emergency Action Plan (EAP) outlines actions to be taken during an emergency. USACE will update the EAP based on advanced assessment results and information from updated inundation maps. In addition, USACE will continue and increase its outreach to improve community awareness of flood risks and risks associated with the dam.  

Fall Creek recreation

Day-use parks: Fall Creek Lake has one day-use park operated by the U.S. Army Corps of Engineers. It  has no associated fees and is open year-round from dawn to dusk. Tufti Park a minimally developed day use area with Fall Creek access, a gravel parking lot, hiking trail and vault toilet. For more information, call the Willamette Valley Project Park Ranger Office at 541-942-5631.

Five day-use sites at Fall Creek are operated by Oregon Parks and Recreation: Winberry Creek Park, North Shore Park, Free Meadows, Lakeside I & IICall either the park office at 541-937-1173 or the State Parks Information Center at 800-551-6949. 

Camping: Two campgrounds at Fall Creek are operated by Oregon State Parks: Cascara Campground and Fisherman's Point Campground. Call the Oregon State Parks Department 541-937-1173 for more information. Cascara also has a life jacket loaner station* available.

One campground at Fall Creek is a private camp for educational purposes: Sky CampThe caretaker can be reached at 541-937-3355.

*Loaner life jackets may not be available due to COVID-19. Be prepared and bring your own.‚Äč

 

Getting around

 

Environmental stewardship at Fall Creek Dam

The Fall Creek uplands and lake provide more than 3,500 acres of habitat for a wide variety of wildlife including   waterfowl, upland game birds, song birds, bald eagles, osprey, black-tailed deer and other species. Rare species found here include salmon, red-legged frogs, and western pond turtles. Western bluebirds and other songbirds breed in nest boxes maintained by the Corps.

The Willamette Valley Environmental Stewardship program focuses on restoring degraded uplands, wetlands and streams on Corps lands. Recent efforts to improve habitat quality for wildlife on Corps’ lands center on replacement of exotic and invasive plants with native trees and shrubs, and restoration of hydrology and topography to support native plant communities and wildlife habitat.

To mitigate impacts of Fall Creek Dam on Chinook salmon, the Corps operates an adult fish collection facility at the base of the dam. The facility collects returning salmon and Corps personnel transport them upstream to spawn. The Corps also promotes resident fisheries within Fall Creek in co-operations with the Oregon Department of Fish and Wildlife. Additionally, the Corps supports ongoing efforts for recovery of the Oregon chub within the Fall Creek basin.

Flood risk management at Fall Creek Dam

Conservation season - April to November: None.
Flood season - November to March: Restrict pool to 822 feet.

For more information, visit our Water page.