Model GH-9000 Constant Upstream Level Control Gates

The automatic level control gate shall be constant upstream level, GH-9000, and be completely self operating with an integrated float ballast design. The gates shall be manufactured by Golden Harvest, Inc., Burlington, WA.

Gates shall automatically control the level upstream of the gates irrespective of the flow through the gates and independently of the downstream water surface elevation, as long as the difference between the controlled water surface elevation and the downstream water surface elevation equals or exceeds the minimum amount stated in the operation requirements below:

  • Maximum upstream water elevation
  • Maximum flow
  • Minimum head differential

The gates shall use force balance principle to control flow. The hydraulic force of the water flow against the gates shall be counter-balanced by buoyant chamber and ballast chambers. No motors or electrical devices, cable and pulley arrangements, or float wells shall be employed in the operation of the gates.

The level control gate shall mount in a prefabricated control structure.

The gates shall be constructed of 304L stainless steel plate and shapes, and designed to withstand the pressure forces produced by the upstream water level at its maximum elevation, with no tail-water.

The gates shall mainly consist of a radial shaped faceplate, suitably reinforced and matching trapezoidal shape sluiceway, a framework including the float and ballasting compartments.

The gates shall include an adjustable counterweight, suitable for accurate, sensitive and stable gate operation.

Option: Prefabricated Control Structure
The prefabricated control structures shall be constructed of type 304L stainless steel.


In accordance with the manufacturer's written instructions.

The gate shall be carefully checked and adjusted to tolerances required in the factory for straight forward field erection and proper operation.

Field adjust ballast in ballast chambers to adjust upstream water level to the desired depth. Contractor to provide the required ballast for each gate.

Accurately place anchor bolts using dimensions furnished by the manufacturer and as specified.

Field Test
A functional test shall be completed by means of varying flow to each gate from minimum to full plant flow. Upstream water levels shall be recorded and if necessary each gate shall be adjusted for satisfactory performance.

Manufacturer's Service
A manufacturers factory representative shall be present at the jobsite for inspection of installation, functional testing, ballast adjustment and certification.