Como Lake's Next Cleanup Is Being Built Under a Soccer Field at McMurray

The three softball diamonds south of Wynne Avenue came out for the sake of Como Lake. Since late September, the fenced-off ground south of Wynne Avenue at McMurray Fields has been dug up for a stormwater system meant to stop runoff before it reaches the lake. The park's new turf field is part of the same project. The digging also comes at a bad time for the lake, because the gains from the last big lake treatment are fading.

The Lake Had Its Best Year in 2023. Then It Slipped.

In 2024, the Capitol Region Watershed District reported that 2023 was Como Lake's best water quality year on record, with excellent clarity and the lowest average annual phosphorus it had measured. That came three years after the district's alum treatment, finished during the week of May 18–22, 2020. Alum keeps phosphorus already in the lake bottom from cycling back into the water.

The improvement did not hold. CRWD's 2025 Lakes Data Summary, dated February 2026, found that Como Lake's water quality dropped slightly in 2025 after two years in a row of heavy summer rain. June 2025 was especially wet. The monitoring station at one of the lake's largest drainage areas recorded its highest June phosphorus load since 2013, right at the peak of algae season. District staff saw green water and algal blooms, and testing done with Ramsey County and the Minnesota Department of Health found what CRWD called "excessively high levels of microcystin in early July." Microcystin is a toxin released during some algal blooms. The district says that testing continues in 2026.

The 2025 figures only make sense next to their baselines:

The bottom row matters most. The lake-bottom phosphorus that alum is supposed to lock away stayed fairly flat for about four years after 2020. It climbed in 2024 and 2025 and is getting close to pre-treatment levels again. CRWD says that rise was expected. Its 2019 Como Lake Management Plan had already warned that more alum treatments might be needed, because so much phosphorus keeps washing in from the surrounding neighborhoods. The district says it will soon analyze how well the 2020 treatment worked.

So alum deals with phosphorus already in the lake. The other half of the problem is new phosphorus arriving with every storm. That half is what's being built at McMurray.

Why the Watershed Ran Out of Places to Build

The 2019 management plan put numbers on the problem. Como Lake's long-term mean phosphorus was 173 µg/L, close to three times the state standard. Meeting the standard would take a 60 percent cut in phosphorus coming from the watershed plus a 95 percent cut in phosphorus released from the lake bottom. The plan describes a 1,711-acre watershed draining to the lake through 22 storm-sewer outlets. It also notes that 17 years of earlier projects had cut incoming phosphorus by about 20 percent while water quality stayed poor.

Most of that watershed is roads, rooftops, parking lots and sidewalks. CRWD's McMurray Fields project page says that in "this developed urban landscape, there are limited opportunities to capture and clean runoff before it reaches Como Lake." CRWD and the city surveyed the 450-acre Como Regional Park and ranked sites by two things: how much runoff each could treat before it reached the lake, and whether open land was available. McMurray had the space.

The city prepared for this a decade ago. Planning started more than ten years ago, and when Lexington Parkway was rebuilt in 2016, the city put a stormwater diversion structure under the road for a future connection. The city's groundbreaking announcement, reported by the Monitor Saint Paul, calls McMurray "one of the few remaining stormwater treatment investment opportunities in the Como Lake watershed."

Where the Rain Will Go

CRWD's current project page says the system will capture runoff from a 160-acre drainage area. That's a little under a tenth of the lake's watershed, collected at one spot. The April 2026 design update to District 10 counted 61 acres of untreated pavement and rooftop inside the area the project serves. Here is how a storm will move through the system once it's built:

1. Runoff from the drainage area collects in an underground storage system at Wynne Avenue and Lexington Parkway.
2. A pump house sends the stored water to three surface infiltration areas. Two are existing basins in the wooded parts of the park. The third is new, near the parking lots and turf, and will look like a rain garden.
3. Some water goes to a fourth infiltration area underneath the new artificial turf field.
4. The rest irrigates the park's athletic fields and green spaces instead of city drinking water.

The system also responds to the weather. The Monitor's account says smart controllers track National Weather Service data and drain the storage ahead of storms so it has room for the next rainfall. That feature matters after a June like 2025's, when a single wet month did much of the damage.

CRWD projects these results each year: 85 pounds less phosphorus, 11 tons less sediment, an 85 percent cut in stormwater flow to Como Lake, and 96 percent less drinking water used for irrigation.

"By capturing, treating, and reusing runoff, we're protecting Como Lake, conserving drinking water, and creating a more resilient community asset for years to come."

That's Nate Zwonitzer of CRWD, quoted in the Monitor Saint Paul's groundbreaking coverage. Mayor Kaohly Her told the same outlet that "investments like McMurray Fields happen when the City and our partners plan together from day one."

What Comes Back Above Ground

The turf part of the project exists because demand for fields was outgrowing what McMurray had. Saint Paul's McMurray Athletic Fields page lists Municipal Athletics adult softball, youth baseball and soccer leagues at the complex. Before construction, it had three softball fields and three artificial turf fields for soccer, football or lacrosse. The three softball fields south of Wynne are being replaced by one five-acre multi-use turf field, which the city says will help Parks and Recreation keep up with programming demand.

The April 2026 design presentation shows what can fit on that five acres:

So softball returns on two diamonds that share the surface with soccer. The ground also has history beyond league play. CRWD's project page notes that McMurray is home to the long-running annual Hmong International Freedom Festival, a two-day celebration and sports tournament, and that the park has a sledding hill and sits next to the Como Regional Park Pool and the Como Woodland Classroom.

Funding comes from two sources. The city's share of the park work comes from Common Cent, Saint Paul's voter-approved sales tax for streets and parks. CRWD's share is funded partly by the Clean Water Fund from the Clean Water, Land and Legacy Amendment and partly by a Stormwater Resiliency Grant from the Minnesota Pollution Control Agency. The sources give different totals. CRWD estimates $8 to $9 million including the park improvements. The city's project page lists $11 million. The Pioneer Press covered the project's plans and funding when ground broke.

Living With the Fence Until Summer 2027

The groundbreaking ceremony was Sept. 23 on the lawn east of the pool. CRWD reports that grading and excavation started Sept. 29. CRWD's Oct. 14 update said Wynne Avenue was still closed and crews would be laying stormwater pipe, installing parts of the underground infiltration system, and starting excavation for the storage system. The city expects construction to end in summer 2027.

Wynne stays closed while the major work is underway: utility crossings, earthwork and the underground chambers. The city's posted detour runs like this:

• From Lexington Avenue: Enter at Wynne, follow one-way Jessamine Avenue, then two-way Beulah Lane and Wynne.
• From Hamline Avenue: Two-way traffic on Beulah Lane and Wynne.
• Exit: Hamline Avenue only.

Across the park at the Marjorie McNeely Conservatory, the second half of the Fall Flower Show runs through Nov. 29, with yellow, dark red, green and white chrysanthemums, including bonsai mums set among Japanese maples, pines and 'All Gold' Japanese Hakone grass. The Holiday Flower Show, with poinsettias in aurora borealis colors, opens Dec. 4 and runs through Jan. 3, 2027. For week-to-week updates, CRWD posts them on its project page and links to them from a QR code on the signs at the site.

With construction scheduled to run into summer 2027, the fence will be up through at least one more summer algae season. When CRWD publishes its 2026 lake results, they will show whether the lake-bottom phosphorus kept rising.

Christian Klempp follows projects like McMurray block by block across Como Park and St. Paul. If you'd like to talk through how the Wynne closure, the new fields or the lake work fit into your plans for a home near the park, schedule a consultation.