Presenter: Chris Hamilton – The Upper Whites Branch Stream and Prairie Restoration at Bluestem Park
Chris presented on a stream & prairie restoration project on the upper reach of Whites Branch; an ephemeral stream on the Fort Worth Prairie located within the ongoing Alliance Town Center mixed-use development in Fort Worth. The project began in 2012 & was 100% privately funded. The 14 acre site had a 9 acre pond that was built in the 1960s. The developer wanted to keep the pond but for liability reasons determined that removing the pond dam & restoring a natural stream channel through the site was the most desirable option.
Peloton Land Solutions was hired to develop a natural stream design for the restoration focusing on geomorphologic factors such as gradient, sinuosity, capacity, & sediment transport characteristics. Ecological factors included native vegetation & wildlife habitat potential. They used the 1900s Hill survey description as reference for soils & plants of Blackland/Fort Worth Prairie habitat in order to replicate. They also looked at historic aerial photos of the site & determined sinuosity & gradient of the pre-existing stream before the pond was constructed in the 1960s.
After much planning & obtaining the necessary permits, the site was graded & the bedrock & topsoil stockpiled for later use. Concurrent construction on I-35 produced abundant Fort Worth Prairie topsoil; which was purchased for use on the project. This native soil was tested, aerated & then used in a custom mix for 3 different zones at the site: riparian, upland prairie, & turf adjacent to hard surfaces such as walkways. Using the stockpiled bedrock, they installed a series of natural stone drop structures to provide grade control & create a natural complex of riffles & runs, mimicking nearby natural streams.
Once Bluestem Park was complete, a maintenance plan was developed. Maintenance staff was taught plant ID, weeding, irrigation & mow versus non-mow areas. Because of a frequent turn-over rate in grounds maintenance staff, it can be a challenge to train & retain specific knowledge of how to manage native landscapes. Prairie sections are allowed to flower & seed before an annual mow.
Adaptive management allows for corrections within the site. Switchgrass & cattails became too aggressive & had to be moderated. Over time, as the stream channel changes, they will reassess vegetation. For example, as sedimentation accumulates, or soils become more wet or dry, plant palettes may change. The stream channel, although engineered, is mimicking natural processes.
Public perception is another challenge. People typically don’t like to see tall grass next to walkways & trails. The project design called for a transition of buffalograss turf adjacent to the walkways then transitioning to taller native grasses & wildflowers beyond. Once the project was complete & thriving, they noticed an increase in flora & fauna including raptors & stream invertebrates. Pollinators became more widespread.
Chris mentioned that his company took the iTree computer program & modified it to figure carbon benefits for grass cover. Peloton also used the Texas Rapid Assessment Method to calculate pre-restoration & projected scores for streams.
Another important factor with acceptance of a project is public education & community involvement. The property managers (Hillwood) have installed nature-themed interpretive signage to teach visitors about the stream & prairie ecosystem. They have coordinated & hosted several public events including fun runs, festivals, geomorphology classes, & the City of Fort Worth’s walking town hall meetings.
The stream restoration area provides a unique, safe, sustainable, and usable green/open space, including a hike-and-bike trail that weaves through a 14-acre prairie restoration site.