Erin Poor (Former Employee)
Science and Products
Fernhill Natural Treatment Wetlands
The amount and type of algae in the Tualatin River affect the river’s water quality and ecological health, as well as its value as a recreational resource. As a relatively new source of summertime flow to the upper Tualatin River, discharges from the Fernhill Natural Treatment System (NTS) have the potential to enhance or degrade downstream water quality. Discharges of low nutrient...
Johnson Creek Basin Hydrologic Monitoring Study
The USGS provides hydrologic data for the Johnson Creek Basin. Real-time surface-water, water-quality and groundwater data, as well as historic data and analyses, help to improve our understanding of the hydrology of the basin.
Tualatin River Basin Water Quality Assessment
In 1990, the USGS began assessing water-quality in the Tualatin River. Almost 30 years later, we are still monitoring conditions in the basin.
City Beavers: Tualatin River Basin Beaver Study
Beavers and their dams are common sights along creeks in the Tualatin River basin. Beaver help create diverse habitats for many other animals, including birds, fish, and amphibians. The USGS studying the affect beaver activity has on the amount and quality of water in local streams, so that agencies in the basin can make strategic management and habitat restoration decisions based on science...
Tualatin River Basin Beaver Study Area
Map of intensive sites and rapid sites where data was collected for the Tualatin River Basin Beaver Study.
Bob The Beaver
Meet Bob.
Bob is a beaver.
Beavers and their dams are common sights along creeks in Oregon. Beaver activity can create diverse habitats and homes for many animals, including birds, fishes, and dragonflies. The USGS are studying beaver dams and ponds in Portland, Oregon, to understand how they affect the amount and quality of water in urban streams. Insights
1. Overview of the Tualatin Urban Beaver Dam Study
Populations of North American beaver (Castor canadensis) have increased in recent years due to decreased trapping, habitat restoration, and recognition of their importance as a keystone species in stream ecosystems (Pollock and others, 2017). Previous studies have shown that beaver dams and associated ponds can change channel morphology, trap sediment (and
5. Effects of Beaver Dams on Sediment Transport
Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.
For this part of the Tualatin beaver study, USGS assessed changes in sediment dynamics along beaver-affected reaches of Fanno Creek at Greenway Park and Bronson Creek. Here, we
4. Effects of Beaver Activity on Water Quality
Beaver dams and ponds alter the movement and storage of water as well as the water quality in a stream reach. To date, little work has been done to quantify the effects of beaver activity on water quality in urban streams.
In this part of the Tualatin beaver study, USGS assessed changes in water quality along beaver-affected reaches of Fanno Creek at Greenway Park
3. Hydraulic Effects of Beaver Dams
Beaver dams and ponds fundamentally alter how water moves through a stream reach. Semi-porous dams can impound water, leading to backwatering, floodplain inundation, and overall changes in wetted area, depth, and velocity.
For this part of the study, USGS:
- assessed hydraulic changes caused by beaver dams across a range of flows using a hydraulic model
2. Beaver Dam Inventory and Beaver Dam Capacity Estimates
Beavers and their dams can substantially change the storage and movement of water through a stream reach. The magnitude of this change is, in part, a function of the number and type of dams plus stream characteristics. If beaver activity is to be considered as a flow-management aid, then understanding the locations where beavers currently are building dams and the