Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9, West of Avenue 34 East & north of County Ninth Street, Wellton

Source document Quoted word for word from HAER AZ-68-E. Not written, edited or summarised by this site.

Radial gate check with drop, Wellton Canal is located west of Avenue 34 East and north of County Ninth Street, Wellton vicinity, Yuma County, Arizona. The canal structure lies within the SE 1f4of the SE 1f4 of Section 25, Township 8 South, Range 18 West, on the Wellton Mesa, Arizona, 7.5-minute U.S. Geological Survey (USGS) quadrangle (photorevised Universal Trans- verse Mercator Coordinates: Zone E

Source document Quoted word for word from HAER AZ-68-E. Not written, edited or summarised by this site.

Construction of the Wellton-Mohawk Division of the Gila Project began in and was essentially completed in With the completion of the irrigation tem, Colorado River water was delivered to previously arid lands in the lower Gila River valley. Construction of the Wellton Canal began in April and was completed in June The Wellton Canal diverts from the Wellton-Mo- hawk Canal at Mile and carries water by gravity flow to a point about 1 mile west of Antelope Hill, then trends west-northwest, delivering water to the central lands of the Wellton-Mohawk Division.

The radial gate check with drop is not individually eligible for listing in the National Register of Historic Places, but it contributes to the function and significance of the Wellton-Mohawk irrigation system (Thompson and Sterner Report Prepared by: Scott Thompson, Senior Historian Statistical Research, Inc. Tucson, Arizona Date: September Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 2) I. PHYSICAL HISTORY A. Date of Construction Radial gate check with drop, Wellton Canal 9.9 was constructed between 1951and1952. B. Architect The Office of the Chief Engineer, Bureau of Reclamation, Denver, Colorado, designed the radial gate check with drop. C. Original Owner The U.S.

Department of the Interior, Bureau of Reclamation (Reclamation) owns the Wellton Canal and all associated canal structures. However, the Wellton-Mohawk Irrigation and Drainage District (WMIDD), a state-chartered agency that was established as the local water users organization that would administer the irrigation project, is responsible for operating and maintaining the irrigation system. D. Builder On April 12, the Morris-Knudsen Company, Inc., of Los Angeles, California, was awarded the con- tract for the construction of the first section of the Wellton Canal, one of three canals that branch off from the Wellton-Mohawk Canal.

Work on the 12-mile section from the head of the Wellton Canal to a point west of Antelope Hill commenced in April and was completed in April (Dayton The radial gate check with drop, at Mile 9.9 on the canal, was one of many canal structures built under this contract. Total contract earnings amounted to (Reclamation 1952a:8). (Note: The Morris- Knudsen Company, Inc., was awarded the contract to construct the second section of the Wellton Canal. Work began in December and the contractor fulfilled all conditions of the contract in June [Reclamation E. Original Plans and Construction Reclamation's Office of the Chief Engineer, Denver, Colorado, produced the original architectural and engineering drawings for the radial gate check with drop.

Dates on the drawings range from January to March The Morrison-Knudsen Company, Inc., built the gate check with drop as part of a larger contract to construct the Wellton Canal and other canal structures. All work was accepted by Reclamation on April 4, (Dayton Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 3)

Architectural and Engineering Information

The radial gate check with drop at Mile 9.9 on the Wellton Canal (Figure 1) is a type of regulating struc- ture. Regulating structures raise the canal water level higher than normal when the canal is flowing at less than design capacity. Checks are one of several structures that perform this function. A check structure employs a gate mechanism, which in its lowered position restricts the downstream flow of water, thus raising the canal water surface when the canal is flowing below capacity. This ensures that an upstream turnout structure delivers its designed capacity. Check structures are spaced accordingly along a canal to maintain the water-surface elevation required by upstream deliveries (Aisenbrey et al.

A drop, another type of canal structure, occurs on the system when a significant change in grade from a higher to lower elevation is required. This irrigation feature combines the check function with a double, vertical drop. Drop structures convey water from a higher to a lower elevation while dissipating the ex- cess energy resulting from the drop that would otherwise cause a disruptive flow in concrete-lined canals. In concrete-lined canals, vertical drops may be up to about Drops are designed with long stilling pools just beyond the drop to control turbulence downstream (Aisenbrey et al. Radial gates are used in irrigation systems to control water-surface elevations and regulate flows.

The radial gate in place at the Wellton 9.9 check is constructed of steel and consists of a curved faceplate, a horizontal beam attached to the concave side of the faceplate, and two pairs of arms that support the face- plate. The convex side of the gate faces upstream against the flow of water. A manually operated hoist mechanism operates the radial gate. Reclamation described the gate operation as follows: Because of the shape of the gate and the relatively long supporting arms, the power re- quired to operate a radial gate is practically independent of the water pressure against its face. The hoist capacity required is primarily dependent on the combination of gate weight and seal friction.

The gates are normally operated by means of wire ropes wrapped on drums installed on the hoist deck. These gates are raised by the wire ropes. The lowering or closing operation is accomplished by slacking the wire ropes to permit th gate to lower by its own weight [Reclamation l]. The radial-gate hoist mechanism consists of a hand-cranked worm gear reducer connected by a steel shaft to two gate drums. Steel cables wrapped around the drums are connected to the lower corners of the radial gate faceplate. The check structure is constructed of reinforced concrete. Water flows into the upstream side of the check, which is shaped like an inverted "V" (Figure 2). At the notch, or center, of the "V" is the radial gate.

A single radial gate is in place to regulate the flow of water through the check. The gate measures x and has rubber seals on the bottom and sides. When the gate is in its raised position, water flows into a concrete-lined sluice. The walls of the sluice are high, 6" thick, and set apart. Each wall sup- ports .the pivot point for the radial gate arms, of which there are four (two for each side of the gate) (Fig- ure 3). Overflow walls are found on both of the upstream sides of the check structure (Figure 4). The tops Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 4) of the walls are positioned just above the control water surface.

Excess water in the canal upstream from the check structure flows over the walls, thus limiting water surface rise in the canal (Aisenbrey et al. A concrete deck with metal handrails spans the check structure to provide access to the gate-hoist mech- anism. The gate drums and worm gear reducer are anchored to concrete pedestals (Figure 5). Water exits the sluice and drops about 10' into an approximately 35'-long section of canal, then it drops a second time from a height of about 3' and continues down the canal.

The canal width of this section, which is immediately downstream from the first drop, is In January the WMIDD added a Cipoletti weir at the point of the second, shorter drop to measure the rate of flow (Charles Slocum, personal com- munication A weir is an overflow structure built across an open channel to measure the rate of flow of water. This ensures the equitable distribution of water to downstream users and the conservation of the natural resource (Aisenbrey et al. Weirs are identified by their openings. A Cipoletti weir has a sharp-crested, trapezoidal opening. The weir structure is located at the second drop and consists of a vertical, concrete bulkhead. A metal, knife-edged weir blade is anchored to the upstream face of the bulkhead.

The crest of the weir blade is level and the sides have a 1:4 slope with sharp, right-angle corners on the upstream side (Figures 6 and 7). Once the weir was in place, the large volume of falling water from the upstream gate check caused a wave action, which made it difficult to obtain accurate measurements. To solve the problem, WMIDD workers precast a large, reinforced-concrete baffle on-site and lowered it into place to reduce the waves (Figure 8). With the baffle in place, the canal section between the first drop and the weir acts as a large stilling pool, allowing WMIDD personnel to accurately measure the flow rate in this section of the canal (Charles Slocum, personal communication (Figure 9). The radial gate check with drop is in good condition.

The canal structure has been in service for over 50 years and the concrete portions show signs of normal surface deterioration. Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 5) III. REFERENCES CITED Aisenbrey, A. J., R. B. Hayes, Warren, D. L. Winsett, and R. B. Young Design of Small Canal Structures. U.S. Department of the Interior, Bureau of Reclamation, Denver. Bureau of Reclamation (Reclamation) 1952a Annual Project History, Gila Project, Arizona. Vol. XVII. U.S. Department of the Interior, Bureau of Reclamation, Denver. On file, Bureau of Reclamation, Yuma Projects Office, Yuma, Arizona. l Operating Instructions, Radial Gates and Radial Gate Hoists. U.S.

Department of the In- terior, Bureau of Reclamation, Design and Construction Division, Denver. Annual Project History, Gila Project, Arizana. Vol. XVIII. U.S. Department of the Interior, Bureau of Reclamation, Denver. On file, Bureau of Reclamation, Yuma Projects Office, Yuma, Arizona. Dayton, Marshall Unit Record of Construction on Earthwork, Canal Lining, and Structures, Wellton Canal Station to Station Specifications No. U.S. Department of the Interior, Bureau of Reclamation, Lower Colorado River District, Yuma, Arizona. On file, Bureau of Reclamation, Yuma Projects Office, Yuma, Arizona Thompson, Scott, and Matthew A. Sterner Inventory and Documentation of the Irrigation System of the Wellton-Mohawk Division of the Gila Project. Technical Report Statistical Research, Tucson.

Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 6) / ... .. ~ ._ ''' Grid - .. 0 -===:::::i -===::::imeters 250 500 750 Scale Universal Transverse Mercator coordinate system and grid , - Datum: North American Zone 11 N Ellipsoid: Clarke Unit: meter Base data: Wellton Mesa 7.5-minute USGS quadrangle (photorevised in Statistical Research, Inc., April ~ ... ;.1 1 Figure 1. Project location Wellton Mesa, Arizona, 7.5-minute USGS quadrangle [photorevised Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 7) Figure 2.

Radial gate check with drop at Mile 9.9 on the Wellton Canal, looking downstream, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 8) Figure 3. Water flowing through the sluice. The arms of the radial gate are anchored to the interior walls, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 9) Figure 4. Overflow on upstream side of check structure, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 10) Figure 5. Worm gear reducer and gate drums on deck of check structure, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No.

AZ-68-E (page 11) r I U.I ::E ~ <;( w er: I- I- I- I/I I.LI .J II,. .. "O 0 ~ ~ I .J z 0 ... 'ii 0 - 0. I- 3: 0 0 w (/) ~r Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 12) Figure 7. A sheet of water flows over the weir crest, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 13) Figure 8. Concrete baffle installed in January to reduce velocity and turbulence of the water, October Wellton-Mohawk Irrigation System, Radial Gate Check with Drop, Wellton Canal 9.9 HAER No. AZ-68-E (page 14) Figure 9. Stilling pool to dissipate excess energy, October