Mayor's Office

Anybody who has been to one of my “Meet Your Mayor” coffee shop chats knows that I love a hot cup of tea. But there is one kind of tea I don’t like: leaf tea.

Leaf tea is the result of fall leaves mixing with rainwater. The leaves leach phosphorus into the water and the resulting brew travels through our storm sewers and into our lakes. In fact, 50% of the phosphorus that reaches our lakes from urban areas is from leaf tea, and the high phosphorus loads in our lakes can result in toxic algae blooms, low oxygen levels and green murky waters.

A key to reducing urban phosphorus loads in our lakes is to keep leaves out of our streets. This keeps the leaves from reaching the storm sewers where the phosphorus-rich leaf tea reaches our lakes. If all residents rake leaves before every fall rain storm, we could reduce the phosphorus loads to our lakes from urban areas by 50 percent.

We can all do our part to help keep our lakes healthy. A typical fall has about eight storms. By raking eight times each fall - raking the leaves from our yards, and clearing them off of the street and away from storm drains - we could have a massive impact.

Leaf management is a whole-community effort. In the City, we work across agencies to understand the best way to manage leaves from an environmental, operational and practical standpoint. The City partnered with USGS from 2012 to 2018 to look at how the City and community could impact water quality through different leaf collection programs. The study showed that it is most impactful for the City to collect the leaves on the streets. Residents can have a major impact by raking or mulching leaves in their yards, and raking leaves from the streets – especially before a rain storm.

City street sweeping crews are also stepping up efforts to collect leaves from roadways. This year, street sweeping machines are running 25 percent more hours each week. And we’re seeing results. Between May and September, City street sweepers have collected an additional 500 tons of materials that will not enter our waterways.

The Streets Division is also piloting a project in the Greenbush/Vilas neighborhood with the Friends of Lake Wingra to collect yard waste during the weekly restricted parking times. By providing residents a predictable, regular timeframe for leaf collection and linking it to existing parking restrictions, we hope to minimize the length of time that leaves are left in the roadway or in piles in the terrace – and ultimately keep the leaves out of our lakes.

It’s up to all of us to keep our lakes clean. Here are some actions you can take:

• Always rake or mulch our leaves before it rains.
• Always clear leaves from the street and gutters before it rains.
• Go to ripple-effects.com. There, you can:
  • Request a free yard sign to remind your neighbors to rake and keep our streets leaf-free.
  • Sign up for text alert reminders to rake before each rain storm.
  • Learn more about the impact leaves have on our waterways.

You can also check the status of City leaf collection through this map on the City website.

It takes all of us to work together, and when we do, our local waterways will be so much better.