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Lake Level Order & Outlet Dam Management

Ever wondered how China Lake's water level is determined and managed? Read on, because we have answers!
 
What determines the water level?

The Lake Level Order (LLO), as defined by Maine DEP. LLOs vary per lake, and each prescribes how high (or low, respectively) water can be throughout the year. The first LLO for China Lake was developed in 1984. It’s been modified a few times since, with the current version (see chart below) dating back to 2014.
 

How is the water level physically controlled?

Via the Outlet Dam in Vassalboro.
 

Who manages and operates the Outlet Dam?

The Town of Vassalboro has performed these functions since 2019. Previously, they alternated between Kennebec Water District and the Town of Vassalboro.
 

How high or low can China Lake’s water level be?

The baseline water level — from which all adjustments are calibrated – is often referred to one of two ways (which can be confusing!): colloquially as the “top of the spillway,” or topographically as “171.5 ft.,” which is the lake’s elevation above sea level.

 

The LLO states water can be as high as 172 ft. (6 in. above the top of the spillway) and as low as 169 ft. (30 in. below the top of the spillway) for a total variance of 3 ft. (36 inches).
 

How long does drawdown take to complete?

This is governed by the rate – in cu. ft/sec. – that water flows out of the dam. The “fall flush” target of 169 ft. (30 in. below the top of the spillway) is usually achieved within several weeks.

Check It Out: pg. 6 -- China Lake Level 2023 bit.ly/3PDXCOl

Lake Level Order Chart

The following guidance went into effect in 2014. 

LakeLevelOrder.JPG
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