As sump pumps in the water-logged Amber Meadows neighborhood continue to suck water from basements, the Great Bend City Council Monday night learned that any remedial steps to permanently solve the subdivision’s aquifer flooding would be costly.
“Our job was to formulate a high-level water management plan,” said Josh Golka with the city’s on-call engineering firm Professional Engineering Consultants of Wichita. He was giving a report on the groundwater study of the subdivision.
The up-front capital costs (wells, permits, piping, controls and design) are estimated at $1,088,000. Annual costs (electrical, monthly inspections, permit reporting and repairs) are estimated at $65,125 to keep it going.
In May, vocal Amber Meadows residents complained about the basement flooding caused by heavy rains this spring, calling for the city to respond. A split council approved contracting with PEC for the $25,000 multi-phase study. The first phase included examining data from existing monitoring wells to paint a historical picture of the aquifer, as well as a map of it.
Now, SCS Engineers, groundwater specialists out of Wichita, have completed phase 2 of the study which includes a summary of the fieldwork and the conceptual dewatering plan. PEC brought in SCS to perform the analysis.
“There were no surprises in the data,” said Kevin Hopkins with SCS.
The second phase proposal suggested five wells to draw down the aquifer and keep it down below the level of area basements. The water would be pumped via subterranean pipes into Veterans Memorial Lake.
As documented in phase one, groundwater elevations in the Great Bend area have been increasing over the past several years. Record precipitation in late 2018 and the first half of 2019 further increased groundwater elevations, resulting in basement flooding throughout the subdivision, the phase one report notes.
“The second phase consisted of data collection efforts on the aquifer’s characteristics, and establishing a geological and hydraulic model of the neighborhood,” Hopkins said. Lastly, concept costs were developed for the installation of the dewatering system.
SCS engaged Environmental Priority Service based in Salina to conduct the aquifer testing. EPS mobilized in early July and completed five borings, Hopkins said.
These determined soil composition, soil permeability and gradient of the water flow. Findings aligned with the regional groundwater model for Groundwater Management District Number Five and other previous testing.
Once the aquifer’s properties were defined, Hopkins said they constructed an groundwater model to forecast well locations and flow rates.
The idea is to establish a groundwater elevation of 1,847 feet above mean sea level. This represents an elevation approximately 2 feet below basement level.
To accomplish this, the five groundwater extraction wells are required at a depth of 40 to 45 feet below grade. Each well would be pumped at approximately 650 gallons per minute to draw the groundwater level down. Well diameters are projected at 36 inches.
Pumps, equipped with variable speed drives, are anticipated to have a 15 horsepower rating. The cost estimate was for running the pumps four months out of the year, but that number could go down in a dry year.
The discharge is routed via subsurface piping to Veterans Memorial Lake.
Some on the council questioned pumping the water into Vets Lake. They wondered if the lake would continually put pressure on the groundwater, exacerbating the problem, or by depositing more water there would diminish the park’s usability.
There is a chance of recirculating the water, Golka said. But, most of the trouble faced by homeowners comes from beyond the city limits, not the lake.
And, Golka said, this was a very preliminary proposal. Other possibilities and downstream impacts would be studied prior to moving forward.
But, he said this is a baseline cost, meaning the Veterans Lake idea is the least expensive option. Other possibilities, such as pumping the water to the Arkansas River, would be much more expensive.
Golka also noted that this covers only the Amber Meadows addition. Although the cost gives some idea of what the costs would be elsewhere in Great Bend, soil conditions vary so much it is hard to make a comparison.
Here is a quick look at what the Great Bend City Council did Monday night:
• Approved the 2020 budget as presented with a 1.365 mill levy increase.
• Approved the Great Bend City Council Strategic Plan. In February, the city began the strategic planning process with public input and input from city personnel, and the resulting three-year plan established seven goals, each with a series of objectives.
• Heard a report on phase two of the Amber Meadows groundwater study. It includes a summary of the fieldwork and the conceptual dewatering plan.
• Tabled action on the city’s on-call engineering firm Professional Engineering Consultants’ $50,000 design and construction contract for pavement resurfacing along Broadway from Harrison to Morton, marking the final street maintenance project for the year.
It will be addressed at the Sept. 16 meeting.
This mill and overlay is a high-priority project for the city. This is for the design and construction administration contract with PEC in order to complete design, bidding, and construction of the project this year. The total construction budget is estimated at $830,000. PEG’s proposal totals $50,000 which includes $42,500 for design services and $7,500 for construction administration services, on-call City Engineer Josh Golka said.
• Approved a tree trimming licence for K&K Tree Trimming at the request of Kelly Jeroue of Great Bend.
• Named City Administrator Kendal Francis as the city’s League of Kansas Municipalities voting delegate at the League of Kansas Municipalities 2019 Annual Conference.
• Heard a departmental update from Francis. He focused on the various water leaks around the city, and he assured the council the problem is being addressed.
• Heard a report from Community Coordinator Christina Hayes. She focused on Party in the Park which took place two weeks ago, and the citywide sidewalk sale and citywide garage sale in July.
• Approved a change of date for the next regular council meeting which would have fallen on Labor Day, a holiday observed by the City. Instead of Monday, Sept. 2, it will take place on Tuesday, Sept. 3.
• Approved abatements at: abatements at 1315 Holland, Accumulation of Trash/Refuse - Kevin and Gina Benker; 1311 Jefferson, Accumulation of Trash/Refuse - Mark Schnoebelen and Diane Inghram Revocable Living Trust; 1307 Jefferson, Accumulation of Trash/Refuse - WHB Inc; 1723 Heizer, Accumulation of Trash/Refuse - Kathie Michael; 1440 12th, Accumulation of Trash/Refuse - James Shaw; 1116 Holland, Accumulation of Trash/Refuse - Henry Vasquez and Sarinana Enrique; 306 Barton Dr., Accumulation of Trash/Refuse - Gerardo Dominguez and Maribel Sanchez; 409 3rd, Accumulation of Trash/Refuse - Francisco Fabela; 1121 Holland, Accumulation of Trash/Refuse - Stueder Rentals; 1318 Frey, Accumulation of Trash/Refuse - Petra & Jose Garcia; and 1015 Holland, Accumulation of Trash/Refuse - Corky and Rachel Moore.