Your Mission…

To  figure out the approximate volume of water (within the trail system area) that Yauger park holds during winter.

To figure out the volume you are going to 1) estimate how many feet your normal walking pace is, 2) count your paces down the long side of the trail this will equal your length , and 3) count your paces down the short side of the trail, this will equal your width. To calculate the volume multiply the Length x Width x  5 for Height . Send us your answer!

You will also learn about where stormwater goes and how it is treated for pollutants.

Yauger Park was specifically designed to capture stormwater runoff from 700 areas of surrounding land. This includes Olympia’s westside businesses and streets. The key function of Yauger park is to reduce pollution and flooding of Olympia’s streets. You can learn more about Yauger Park by visiting

PLEASE NOTE: There are 2 entrances into the park. If the gate is open, take the first entrance and park in the lot. If it is closed, you can park in the far lot.


Route 45 or 48

Welcome to the trail!

As you walk the trail look for each of the features listed below. 

Permeable and porous parking lot – See how the parking lot allows water to infiltrate into the ground! When natural areas are developed into urban areas, rainwater can no longer easily soak into the ground. Things like roof tops, sidewalks, and pavement do not allow water to filter into the ground, causing the water to runoff and potentially cause flooding.

Anything that doesn’t allow water to pass through into the ground is referred to as an impervious surface. In the urban area, there are more impervious surface areas than there are natural areas, so without having a functioning stormwater plan, roads and urban areas can flood.

Permeable pavement and pavers are paving systems that are porous, so they allow water to soak into or infiltrate through the pavement draining into the ground.

Did you know? Vehicles are the #1 cause of pollutants in stormwater. Leaky vehicles, chemicals from tires, and brake pads are all toxic to fish and other organisms in streams. Allowing stormwater to infiltrate into the ground, helps to decrease these pollutants before they reach our steams. Plants also absorb pollutants helping to keep them out of stormwater.


Bio swales- Biofiltration swales are wide, ditch like channels that use grass or other dense plants to filter out sediment and oily material, or pollutants as they collect and transport stormwater. As stormwater passes through the swale, pollutants are removed by the combined effects of filtration, infiltration, and settling.


Concrete weirs – Concrete weirs are designed to slow stormwater flow and creating pools for sediment to settle to the bottom. The cobble bars below the weirs help prevent erosion from fast flowing water.


Pond – This human-made pond is designed to hold and filter stormwater runoff and provide urban wildlife habitat. This pond can hold up to 27 million gallons of water! That’s enough to fill 36 Olympic swimming pools! Over time, the water is gradually released to Black Lake Meadows  stormwater facility through a series of pipes and wetland channels. The water eventually flows into Black Lake Ditch to  Percival Creek and out into Budd Inlet.


Habitat – Native plants were planted in and around the human-made pond. These plants help filter stormwater in the pond like the raingardens and bioswales. These plants also create habitat, providing food and shelter for wildlife. The ponded water at Yauger Park hosts many wildlife species such as native birds, amphibians and insects.

If you listen closely you can hear the call of the Red-winged Blackbird.


Winter flooding of Yauger Park

Yes, this is on purpose! Even with all its water-helping features, Yauger Park isn’t big enough to manage all the stormwater runoff it receives—there’s just too much impervious surface in the surrounding basin. That’s why the entire park is designed to flood. During exceptionally high rain fall events, standing water can fill the park up to its northern margins. City of Olympia crews monitor the water levels and release the excess water in a controlled manner to minimize flooding downstream.

Where does the excess stormwater flow?

To Black Lake Meadows Reserve! Check out the Nature Sleuth game for the reserve to learn more!



You have learned all about stormwater at Yauger Park and where it goes! Be sure to send us your stormwater volume calculation! Once your calculation has been submitted, a park specific sticker will be sent to you!