Zylstra Dam No 2

Tr-False Bay· San Juan, Washington· Built 1963· Earth·
Low Hazard Irrigation Local Government

Key Takeaway

Zylstra Dam No 2 is classified as low hazard in Washington. It was completed in 1963 and is 63 years old. Its primary use is irrigation.

Physical Details

Dam TypeEarth
Max Storage430 acre-ft
Normal Storage280 acre-ft
Surface Area280 acres
Drainage Area9 sq mi
Max Discharge117 cfs
Year Completed1963 (63 years old)
NID IDWA00163

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: November 7, 2023
State Regulated: Yes
Regulatory Agency: Washington Dept of Ecology

Ownership

San Juan County Land Bank

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Zylstra Dam No 2?

Zylstra Dam No 2 is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Zylstra Dam No 2?

Zylstra Dam No 2 is owned by San Juan County Land Bank (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Zylstra Dam No 2 built?

Zylstra Dam No 2 was completed in 1963, making it 63 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Zylstra Dam No 2?

Zylstra Dam No 2 serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

When was Zylstra Dam No 2 last inspected?

Zylstra Dam No 2 was last inspected on November 7, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.