Gilleland Creek is a 31 mile tributary of the Colorado River that begins northwest of Pflugerville, Texas. The creek confluence with the Colorado River is located downstream of Lady Bird Lake. The creek watershed is 76 square miles located in eastern Travis County, and in the Texas Blackland Prairie Ecoregion, specifically the Northern Blackland Prairie Level IV Ecoregion 32c. The cities of Austin, Round Rock, Pflugerville, and Manor are all found in the watershed boundary. Within the City of Pflugerville (‘City’) jurisdiction boundaries, much of the riparian area along the creek is in public park lands.
The bed and banks of the creek are comprised of limestone bedrock and alluvial soils. The perennial flow through the City is comprised of spring water, storm water runoff, and wastewater effluent from Windermere Wastewater Treatment Plant (WWTP). Aquatic animal life in the creek includes zooplankton, mollusks, annelids, crustaceans, insects, fish, amphibians, and reptiles. Plant life within the creek and along the banks include phytoplankton, algae, mosses, ferns and aquatic vascular plants.
On September 23, 2015, a contractor working for the City of Pflugerville broke an 8 inch water main spilling an estimated 560,000 gallons of chlorinated water into Gilleland Creek. During an investigation by Texas Park and Wildlife Department (TPWD), it was determined that the discharge killed an estimated 1,575 fish. The restitution value of the lost fish and investigation cost was calculated to be $1,047.51.
In 2004, the Gilleland Creek (Segment 1428C) was identified as impaired for concentrations of Escherichia coli (E. coli) that exceeded Texas water quality standards for contact recreation. In 2007, a Total Maximum Daily Load (TMDL) was adopted by Texas Commission on Environment Quality (TCEQ), and an Implementation Plan (I-Plan) was developed to provide direction to TCEQ and stakeholders for improving water quality and reducing E. coli concentration in the creek. The City has considered coordinating a riparian restoration project on Gilleland Creek involving the public as an I-Plan voluntary action toward meeting contact recreation standards.
The City of Pflugerville proposes to implement a riparian restoration project along Gilleland Creek to serve as an expedited settlement for the restitution cost of lost resources, resulting from the fish kill that occurred in September 2015. The project will also serve as a TMDL I-Plan voluntary action for improving water quality and reducing E. coli concentration in the creek.
The project will focus on Pfluger Park within the limits of Pfluger Park Loop, Gilleland Creek Trail, and N. Railroad Ave. The length is approximately 0.5 mile and the total area is approximately 11 acres. The riparian zone within the project area has become dominated by invasive vegetation (primarily Ligustrum) which produces a dense canopy that has eliminated much of the understory growth. Consequently, the creek banks under the dense invasive canopy are barren of grasses and other native vegetation. Eliminating the invasive plant dominant canopy, and restoring barren areas along the creek with deep rooted, diverse plant communities will provide a buffer for reducing fecal bacteria loads to the creek, reduce bank erosion, improve the chemistry and hydrologic characteristics of the soil, and improve aquatic and terrestrial habitats for wildlife.
The City Parks and Recreation Department and the Environmental Section of the Development Engineering Department will plan and coordinate volunteer groups which will remove invasive vegetation and other unwanted vegetation (i.e., poison ivy, etc.), then plant native grass and shrub seeds, and plant native tree seedlings within cleared areas. The volunteer groups will also provide ongoing maintenance to ensure invasive vegetation elimination, and native vegetation establishment. Trash and debris removal along the creek will be ongoing to reduce visual blight, and reduce downstream transport. There will be selective downed tree removal from the waterway to facilitate drainage during high flow events.
Boots on the Ground Work Begins
On October 6, 2018, The City Community Services Coordinator, Mr. Eddie Garcia organized a creek clean up at Gilleland Creek Park. Volunteer participants included the Rotary Club of Pflugerville, the INTERACTOR (youth group of rotary), American Legion Kerlin-Lyerly Post 154 of Pflugerville, the Pflugerville HS Key Club, Operation Supply Drop, and the City Environmental Specialist. Participants met in the Gilleland Creek Pool parking lot at 9 AM and worked until 11:00 AM removing trash within the creek bed and along the banks from Railroad Ave. to the first upstream pedestrian bridge crossing. In addition, large pile of dead limbs was removed from the creek bank in Gilleland Creek.
A second work day is scheduled for November 8, 2018. During this event, City Parks and Recreation Department staff, and City Environmental Specialist will partner with the 57th Signal Battalion from Fort Hood, and resident volunteers to remove more trash and debris along the Gilleland Creek, and selective removal of fallen trees from the banks and waterway through Pfluger Park. In addition, invasive vegetation will be removed from a selected area along the stream bank. A riparian seed mixture, and tree seedlings will be planted in the cleared area. The areas that are cleared, seeded and replanted will be corded off and signs will be installed informing the public of the project and to stay off the treated areas.
Historical photos and summary descriptions of the Gilleland Creek Riparian Restoration Project volunteer events are found at this link.
If you would like to become a volunteer for the Gilleland Creek Riparian Restoration Project, contact Mr. Garcia at (512)990-6360.
The riparian area along Gilleland Creek within Pfluger Park that is dominated by Ligustrum. This is an example of an area that will be targeted for eliminating the invasive vegetation, and restoring barren soil along the bank with deep rooted grasses, shrubs and trees that are native along Blackland Prairie streams.
This is an example downstream transport of trash and debris that has become trapped by downed trees. The trash is visual blight and detrimental to the environment. The downed trees and debris can also obstruct drainage during high flow events.