By Michael Ourada – Just a handful of blocks southeast on Capitol Parkway, a favorite location for Lincolnites of all ages is getting a bit of a makeover in some places.The Lincoln Children’s Zoo underwent a project by the city government to reduce or even eliminate runoff into and pollution of Antelope Creek from the zoo. In 2009, the creek was found to contain over five times the federally established limit of E. Coli and ammonia, a notable amount of which was coming from animal waste by the zoo, the rest coming mainly from other wild and domestic animal waste.
With over 81,000 miles of rivers and streams running through the state and 65% of the Ogallala Aquifer sitting underneath, Nebraska has an important role in maintaining clean water for the midwest. In a city-wide effort to curb the pollution of Antelope Creek, these changes at the zoo are just one step in the process.
The open house to unveil this project at the zoo was in May of 2013, but the construction itself began around August of last year. The project is still undergoing at the moment, but the zoo with its new addition is open for visitors to see and learn about.
According to the city of Lincoln website, 180,000 people visit the zoo on 27th street every year, which is around 65% of the city’s population. Unfortunately, water and waste from the zoo would run off and seep into the creek whenever it rained, pushing the levels of pollution above EPA requirements and putting the creek on the agency’s list of “Impaired Waters”. The EPA defines impaired waters as any body of water that fails to meet the expectations of section 303(d) of the Clean Water Act of 1972.The project aimed to not only pull our creek from the list, but also to educate the public about water water purification techniques used there at the zoo and around the country.
While there are a lot of impaired waters in the state of Nebraska, the water quality here is quite high compared to the other states in the EPA’s Region 7 (Nebraska, Iowa, Kansas and Missouri).
Jared Nelson, an Engineer with the city of Lincoln that worked on the project, was able to better detail what exactly is being done. “There are several different components, one of them being permeable pavers at the plaza,” said Nelson in an interview. The plaza at the entrance used to be paved with regular concrete, but that has been excavated and replaced with a permeable paver, so “the rainwater will infiltrate through the pavers into a storage area beneath them to hold it. It’s just a bunch of aggregate (rocks and large gravel) about 12-16 inches thick. There’s a lot of void space for water to fill up, and there are lots of aerobic and anaerobic processes to help clean that water.” Once being cleaned, a special drainage system would slowly let that water seep back into the creek. This slowed draining, according to Nelson, is to help reduce flooding as well as clean the water, as before all of the rainwater would wash directly into the creek and that wave of water would start to flood other areas.
The other part of the cleaning project Nelson highlighted was what he referred to as “bio-retention areas.” These areas were described as “engineered rain gardens” extra things built in. Each area has a depression of land that would collect the rainwater, and the ground itself alongside dozens of specialized plants would help clean and filter many chemicals out of the water. At the bottom of these areas there is a perforated pipe which allows the clean water to slowly seep into it and drain back into Antelope Creek. Nelson said that they are still waiting on a few more plants to be shipped to Lincoln to complete them, but there will be several throughout the zoo. There will even be one at the end of the parking lot on the north side, with a special sediment trap to keep the sand and gravel used in the winter there from killing the plants or otherwise destroying the system.
While the primary goal of this project was the water itself, education was also a priority. The zoo will have signage in various locations explaining how the bio-retention areas work, as well as other methods of cleaning water used by the city of Lincoln.
The City of Lincoln Watershed Management Division’s webpage provides a list of five things that you, the reader, can do right now to help improve Lincoln’s water and make it safer for everyone.
If you or somebody you know wants to get involved and actively help keep our waterways clean, the Department of Public Works and Utilities has multiple programs to volunteer for, including a Stream Clean-up, Adopt-a-Stream, or joining the Stormwater Street Team.