PROJ00434

• Contract/PO #: C153337
• Contractor Name: Farmers Extension Ditch & Highland Lake Lateral Company
• Contract Type: Loan
• Water District: 1
• County: Weld
• Bill Number: FSA
• Loan Projects - Doc Type: Feasibility Study

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will be addressed later in this report.

Another problem with the metering gates is that there are times when it is im-

possible to deliver the desired amount of water to a stockholder because of the

height at which the gate was set. There are usually two, three or more metering

gates behind each check structure. The ditch rider has done a good job learning

the height at which the check structure needs to be set to deliver the proper

amount of water. There are time, though, when more than one of the farmers

whose meter gate is behind the same check structure has to have a certain amount

of water delivered at the same time on the same day. At these times, it is im-

possible to deliver the required flow to at least one of the farmers since the

elevation and size of gates and their relative location are not exactly right

for the amount of water requested.

We recommend for the problem of excessive silt and trash buildup within the metering

gates, that a regular maintenance program be set up so that the gates can be in-

spected on a regular basis. We recommend that the gates be check individually

every two (2) weeks for silt buildup and trash accumulation. Should excessive

silt be found at the bottom of the gates, then they should be cleaned thoroughly.

Excessive silt, we feel, is when the silt is built up so that it, in any way,

blocks the small inlet pipe to the measuring ports. This is also shown in Ex-

hibit 2.

We also recommend that when new metering gates are installed, flow requirements

be estimated for each gate so that the new gates can be installed at the proper

height and will have new flow pipe of the proper diameter. A way to avoid the

problem of height setting is to use an alternative measuring device, a Parshall

Flume. The Parshall Flume is used considerably in Colorado. A Parshall Flume

is a specially built channel which forces water through a defined cross sectional

area. One is able to directly measure the height of the water at a point where

the cross sectional area is known and then obtain the flow through the flume by

using a height-discharge graph supplied by the designer or manufacturer. This

type of measuring device is very accurate, but more expensive to install than a

measuring gate. It is easier to keep clean of trash and silts because it is an

open channel and not a closed conduit. We recommend the use of Parshall Flumes

over metering gates if funds are available.

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