Zylstra Dam No 2 dam
Zylstra Dam No 2
Zylstra Dam No 2, located in San Juan County, Washington, was completed in 1963 and is owned by the local government. The dam's primary purpose is irrigation, with a maximum storage capacity of 430 acre-feet and a normal storage capacity of 280 acre-feet. The dam is an earth-filled structure with a hydraulic height of 25 feet and a structural height of 19 feet, designed to regulate the flow of Tr-False Bay.
The dam is regulated by the Washington Department of Ecology and is subject to state inspection, enforcement, and permitting. Despite its low hazard potential, the dam's condition has not been rated and there is no Emergency Action Plan (EAP) in place. The last inspection was conducted in April 2019, and the dam is deemed to be in satisfactory condition. The dam has not been modified since its completion, and there are no associated structures or outlet gates.
Overall, Zylstra Dam No 2 plays a crucial role in supporting irrigation activities in the region, highlighting the importance of water resource management and infrastructure in mitigating the impacts of climate change. The dam's presence underscores the need for continued monitoring and maintenance to ensure its safe operation and effectiveness in water regulation. As climate enthusiasts, it is essential to recognize the critical role of dams like Zylstra Dam No 2 in sustaining water resources for agricultural and environmental purposes in the face of changing climate patterns.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Zylstra Dam No 2 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Nooksack River At Ferndale | 2,290 cfs | → |
| Samish River Near Burlington | 88 cfs | → |
| Skagit River Near Mount Vernon | 13,300 cfs | → |
| Dungeness River Near Sequim | 236 cfs | → |
| Olsen Creek Near Bellingham | 1 cfs | → |
| Carpenter Creek At N Shore Drive Nr Bellingham | 1 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Zylstra Dam No 2.
Boat launches
- Dock Road 98, San Juan County
- San Juan County
- Cayou Quay Marina
- Hummel Lake Road 674, Lopez Island
- Odlin Park Road 177-199, Lopez Island
Campgrounds
- Spencer Spit State Park Campground
- Cascadia Marine Trail Campsite
- Moran State Park Campground
- Fox Cove Camp
- Washington Park Campground
- Snoring Bay Camp
Paddle runs
- Sleepy Hollow Creek To Olympic Nf Boundary
- Usfs Road 2870 Bridge To Confluence With Dungeness River
- 1.4 Miles Upstream From Confluence With Elwha River To Confluence With Elwha River
- Olympic Nf/Olympic Np Boundary To Usfs Road 2870 Bridge
- Headwaters And Includes All Tributaries To Confluence With Elwha River
- Silver Creek To Sleepy Hollow Creek
Track Zylstra Dam No 2 in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Zylstra Dam No 2
Where does the data for Zylstra Dam No 2 come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Low hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Zylstra Dam No 2.