In the lower levels of the Denver Botanic Gardens, the nonprofit’s herbarium holds more than 70,000 plant specimens as well as fungal samples and plant DNA. The plants are pressed in blotting paper to remove water and preserve the specimen.

Christina Alba, a research associate at the Gardens, has been working since April to collect a small portion of the samples from the High Line Canal trail system. The project will span into September to collect plants from all seasons.

“These collections are living data,” she said. “It’s not just dusty old stuff stuffed away. People are actively using it.”

The herbarium at the Botanic Gardens, 1007 York St., is mostly concentrated on plant samples from Colorado, Alba said. Her recent project with the Denver-based High Line Canal Conservancy will help create a better picture of what plant life lives along portions of the 71-mile trail system.

The High Line Canal Trail is a greenway that stretches from an area southwest of Littleton to northeast Aurora. The trail winds through south Denver through Virginia Vale and the Cherry Creek Gold Club. A little over 17 miles of the trail system runs through Denver.

The canal was first built in 1883 as an irrigation ditch and was purchased by Denver Water in 1924. Denver Water still uses the ditch to provide irrigation water to about 70 customers. Jose Salas, a media relations specialist with Denver Water, said it only runs water for short periods of time through the canal from April to October. But that also depends on how much water the state receives.

“Once an engineering marvel, the canal is not an efficient means of delivering water,” Salas said in an email. “About 70 percent of the water seeps into the ground or evaporates before it reaches customers.”

Denver Water opened the area to the public for recreation in 1970.

Alba and a team of 10 volunteers have been collecting samples from every plant along the canal to take back to the Botanic Gardens herbarium. From there, botanists can use microscopes to indentify the plant. Then, the Botanic Gardens will research that plant and whether it’s native to Colorado.

The data being collected by the Botanic Gardens across Colorado is not being hoarded in the herbarium for only scientists to see, Alba said. The organization has been digitizing its archives and making them available online for people to research plant trends and species data.

“People 20 years from now can search the High Line Canal and link to the species list that we generate,” Alba said.

The amount of plant life along the trail depends on the area and how much water it gets. Human interaction in the area has also changed the types of plants growing there. In some spots, residential gardens are directly next to the trail. Plants from those gardens have traveled across the path and down toward the canal itself.

“There’s a lot of influence onto the corridor,” Alba said. “There’s that native ecosystem, or the original ecosystem, and what kind of plants were there, but now there’s that human imprint laid over that.”

Plant counts will help bring data back to the Highline Canal Conservancy, which is working to build a new master plan for the canal’s future.

The master plan will also look at landscaping around the trail, including drought-tolerant plants and using storm water. Josh Phillips, manager of community initiatives with the conservancy, said Denver Water will stop delivering water to the canal in the next few years. The conservancy’s master plan is looking into retrofitting the canal to use storm water for other properties.

“We really want to understand how the ecology of the canal might change as storm water is introduced into the system,” Phillips said.

He added that retrofitting the canal for storm water use would be cheaper than building new storm water retention facilities. The conservancy is hoping that storm water will help keep the vegetation around the canal thriving.