The pavement of Minneapolis residential streets is declining quickly enough that if more money isn’t spent within 10 years, many roads will need expensive reconstruction rather than a much cheaper resurfacing, city public works officials said Tuesday.

It would take a new investment of $30 million annually over the next 10 years to offset the deterioration of an aging network of residential streets largely built in the 1960s and 1970s, Public Works Director Steve Kotke told City Council members at a meeting Tuesday. But even a lesser sum would help, he added.

The outlook has ramifications for city property owners because typically about one-quarter of the cost of street projects is paid through assessments, while the balance is paid through property taxes assessed citywide. The city now spends about $25 million annually on street repairs.

Kotke said that with an additional $30 million annually, the average condition of all types of city streets could be brought to fair condition, as measured by the city’s rating system for the surface condition of streets. But there’s no consensus on how to raise the money.

There have been discussions at City Hall about a long-term borrowing program to pick up the pace of street renovation, but no solid proposal has emerged. The question of street investment has gained some urgency because park officials are asking the council to put a park funding proposal on the November ballot. That calls for spending $15 million annually for 20 years for neighborhood park repairs.

Council Member Lisa Bender said “it seems irresponsible to me” for the city to make commitments to parks without considering street needs. Mayor Betsy Hodges said in late January that the city needs to make capital investments in both parks and streets, and a spokesman said Tuesday she’s continuing to work with council members to find a way to increase street spending.

Kevin Reich, the council’s point person on public works matters, said it’s time for a policy discussion on how to meet the “indisputable” needs Kotke outlined, including replacing older utility pipes if streets are reconstructed.

Deteriorating streets

The Department of Public Works projects that the condition of residential streets will fall to an average rating of poor by about 2023 at the current rate of investment. The department rates each street paving area every three years on an index of 1 (low) to 100 (freshly paved) based on their surface cracking. Residential streets most recently recorded an average rating of 71, which puts them at the high-end of the range for fair condition.

But the department also projects the condition of residential streets will plummet fastest among the city’s three street categories, hitting an average rating of 50 — poor condition — by 2023. That’s significant, Kotke told the council, because below 50, a street is so far gone that expensive reconstruction, which essentially rebuilds a street from its base up, is the only feasible option.

When streets are in better shape, it’s cheaper to resurface, which involves shaving off a layer of deteriorating asphalt and applying a fresh coat, plus making minor spot improvements. But that typically deteriorates after 15 years.

Kotke’s department projects that in 20 years residential streets would decline to an average rating of under 20, or very poor, at current spending.

The city also rated streets eligible for state aid, typically higher-volume arterial and collector streets, at an average of 69, also fair, but projected they won’t worsen as fast as residential streets. The city in recent years invested much of its street improvement budget in resurfacing such streets.

The city typically places lower priority on the condition of alleys, which have lower traffic and lower speeds, and the catchall category of “local” streets, often found in industrial areas. They’re rated at 46 and 56 respectively, and projected to drop to the very poor level in 20 years.

City officials said the job of properly maintaining streets was crimped by an early 2000s cut in state aid to local governments and by the city’s need to meet skyrocketing pension costs.

The city has since resumed a more regular program to seal coat its streets to better keep moisture from infiltrating them and cracking them when it freezes, an important early step to keep streets from deteriorating.

Steve Brandt • 612-673-4438

Twitter: @brandtstrib