Pumping Systems The existing pump systems are single, large submersible fixed speed pump stations. In their current configuration operation only allows for high flow demands working the top half of the pumps available discharge flow. Once irrigation scheduling runs out of a combination of zones to operate within this range, the pump will struggle to work at the lower flows and will not operate efficiently. The lower flow problem was overcome by combining multiple zones on one station at the higher flows. This method is not flexible enough to be efficient or handle any future site changes. In order to efficiently irrigate, the existing pump stations should be upgraded with Variable Frequency Drive (VFD) control panels to maintain the maximum constant peak flow requirement and operate effectively at changing flow rates while main- taining a constant pressure. The panel should include automatic safety and monitoring features to help protect both the pump station and site. With the VFD, the pump should operate smoothly at varying flows and a constant pressure for more than half of the pumps high-end flow range. On vertical turbine pump stations, the lower flows are handled with a separate small “jockey pump”. This will need to be handled with smaller zone flows and closer attention to scheduling. The current lack of safety features to shut the pump off in the event of a mainline break may cause flooding until the run- ning irrigation cycle is completed. The use of a pump start relay also requires additional time to recharge the mainline to the required pressure because the system was shut down between irrigation cycles. The pump station should also include an automatic downstream self-cleaning scanning filter with pressure differential auto- matic flushing. This will remove any smaller debris (i.e. sand) that makes it through the primary pump filtration and will clog drip irrigation. The scanning filter reduces maintenance time required to clean and replace clogged nozzles and drip filters. The updated pump controls will shut down the pump in the event of an alarm condition (such as excessive flow due to break), and attempt a restart. If alarm conditions are not met, the system will stay shut down until attended, repaired and manually restarted. The restart will use a ‘’Line Fill Control’’ program which operates at lower flows and pressures until the mainline is filled to assigned operating pressure. It is then returned to automatic operation. Additional safety flow and digital monitoring will be available with the PLC not currently included with the existing pumping systems. These alarms will be displayed on a screen at the pump station for review and reset. Error logs will be stored elec- tronically at the station for review by maintenance personal, should the pump not operate properly. Irrigation System Replacement Costs These costs are system-wide and include irrigation costs/project as also shown in budget estimates for implementation phasing. The following projected construction costs are based on historical contractor pricing for the Colorado Front Range area. It is anticipated that large irrigation projects at UNK will attract local irrigation contractors as well as some of the larger commercial contractors from Colorado’s Front Range.
Notes: (1) Tap and meter does not include local tap development fees. (2) In many areas, the irrigation system and sod covers the area directly to the foundation of buildings. To prevent problems caused by irrigation water too close to buildings, a 5-foot “dry zone” around the foundation perimeter, is recommended. This will include the removal of sod and existing irrigation and replacement with a five-foot gravel strip over filter fabric with land- scape edger. The irrigation system will be designed to irrigate outside this five-foot zone. Implementation & Budget Implementation of the Landscape Master Plan will occur over the next 20 years but significant changes are already planned for the near future. The proposed improvements are organized into project areas and prioritized based upon a current understand- ing of the University’s initiatives, commitments, and potential funding. It is anticipated that these priorities will change over time and so the order of implementation projects will be adjusted. Following are preliminary cost estimates for each project. These estimates are provided for use in assessing budgets and organizing projects. The cost for each project will change based upon the design developed at a later date.
Projects in Order of Chronological Implementation 1. Central Fountain and Mall Connections 2. Rte. 30 Trail and Streetscape 3. Health Science Education Complex 4. Centennial Walk Ph I and Nebraskan Green 5. West Gateway & Univ. Dr. Ph I 6. 26th St Mall West 7. East Gateway 8. Centennial Walk North & N. 9th Ave. 9. West Park 10. Coliseum Way 11. University Green 12. Fine Arts Garden 13. 19th Ave. Multi-Use Trail & Streetscape 14. University Drive Ph II 15. Tail Race 16. Founder’s Quadrangle 17. University Drive Ph III
New systems
2,343,578 sf at $.65 per sf
$ 1,992,041.00
(Areas shown in Exhibit ‘A’) 2” PVC mainline at 24” depth 2 1/2” PVC mainline at 24” depth 3” PVC mainline at 24” depth 4” PVC mainline at 24” depth 6” PVC mainline at 24” depth
7,710 lf at $2.35 per lf 15,125 lf at $4.22 per lf 1,550 lf at $5.59 per lf 500 lf at $5.10 per lf 140 lf at $10.91 per lf
$ 18,019.00 $ 63,828.00 $ 8,665.00
$
2550.00
$ 1,418.00 $ 18,000.00 $ 168,000.00 $ 25,200.00 $ 5,400.00 $ 7,000.00 $ 16,000.00 $ 10,000.00 $ 11,500.00
Central Control System
Controller 2-wire decoder, wire/24station -14 Replace backflows w/ RP-LF w/ enclosure -12
at $12,000.00 ea at $2,100.00 ea
Disconnect existing potable points points of connection Boring for Sidewalk sleeving Upgrade pump control panels Misc. landscape improvements/repairs
-6
at $900.00 ea
(1) 2’’ dedicated tap and meter
(2) Add gravel zone around all buildings (to be determined)
$
000.00
Estimated system replacement costs
$ 2,347,621.00
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Chroma Design Inc.
University of Nebraska - Kearney Campus Landscape Master Plan
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