Unmanned Aircraft Systems and the HCFCD
The Harris County Flood Control District is testing the use of small, unmanned, remotely guided aircraft as a cost-effective tool for conducting flood control project surveys, and for collecting maintenance-related data and imagery.
The Flood Control District joins a wide range of government agencies – from public works and parks departments to the U.S. Army Corps of Engineers – who use unmanned aircraft systems (UAS) to more safely and efficiently:
- Inspect infrastructure
- Collect geo-spatial data about what’s on the ground in a particular location
- Conduct plant and animal species surveys
The picture on the LEFT shows a typical UAV flight pattern within Flood Control District boundaries, and the nearby property and road images that could be captured as part of that flight. The picture on the RIGHT shows the final rendered image provided to the Flood Control District, masking private property and areas outside of Flood Control District boundaries.
With jurisdiction over more than 2,500 miles of open and closed channels across nearly 1,800 square miles, and with limited staff, the Flood Control District anticipates a variety of potential benefits from the use of UAS:
- They make the inspection process safer for inspectors who often need to access waterways and enter remote, overgrown areas.
- They allow inspectors to cover more ground in a work day, as compared to boots-on-the-ground inspections.
- Future applications could utilize different image-capturing capabilities to identify plant stress, and quantify success of site stabilization and tree planting sites. These tasks help to determine when a project has been successfully completed by a contractor, or to identify contractor performance issues.
Flood Control District use of UAS technology is guided by both federal and state law, including the Texas Privacy Act. Recent contractors, HUVRdata LLC and Precision Aerial Compliance Solutions, are among UAS service providers vetted and credentialed by the National UAS Credentialing Program (NUASCP).
UAS for Bioswale Demonstration Project
The Flood Control District has established native grasses and wildflowers in backslope swales as part of a demonstration project to collect data and determine benefits for water quality enhancement and runoff volume reduction. As part of the monitoring phase, the Flood Control District is partnering with researchers at the University of Texas-Arlington to measure the infiltration rate of water into the soil. Instead of using time-consuming traditional efforts to measure this parameter, drone-based data collection will be used in early June 2019 to improve results and efficiency.
UAS near Buffalo Bayou
In early December 2017, a Harris County Flood Control District Unmanned Aircraft System provided pre-construction documentation for a project to install junction boxes at the confluence of two Buffalo Bayou tributaries near Barker Reservoir and State Highway 6.
Tributary W170-01-00 helps provide drainage for nearby Interstate Highway 10. The construction project installed a concrete drop structure and reinforced concrete boxes to enclose the channel and repair erosion along Tributary W170-01-00, which empties into Tributary W170-00-00 near the northeast edge of Barker Reservoir.
An Unmanned Aerial Vehicle operated by a Flood Control District pilot documented existing site conditions and construction progress along a 900-foot section of Tributary W170-01-00. Construction began in late 2017 and continued through the summer of 2018.
UAS over Mueschke Road at Grand Parkway
In November 2017, the Harris County Flood Control District used an UAS to conduct construction inspections in advance of a project to improve stormwater conveyance on a tributary of Little Cypress Creek in northwest Harris County. Flights took place before and during construction along a three-fourths-mile stretch adjacent to Mueschke Road, south of the Grand Parkway (State Highway 99). The quad-rotor UAV was operated by a licensed Flood Control District pilot.
Data gathered during the flights produced a three-dimensional photo mosaic used to chart progress on construction and to track construction materials. The Flood Control District’s Construction Division used these Mueschke Road flights to test whether unmanned aircraft provide a cost-effective new tool in monitoring construction projects.
The goal of the Flood Control District project along the Little Cypress Creek tributary formally identified as HCFCD Unit L112-01-00 is to allow for stormwater drainage improvements in connection with a future county roadway project on Mueschke Road. Construction on this project was completed in 2018.
UAS over Spring and Cypress Creeks
Beginning in October 2017, the Harris County Flood Control District used a UAS to survey portions of Spring and Cypress creeks for channel blockages caused by Hurricane Harvey. The aerial assessments helped guide the Flood Control District’s debris removal efforts, and ensure that these channels are ready to handle the next rain event.
A UAV operated by Textron Systems, a licensed Flood Control District contractor, flew over and along about 34 miles of Spring Creek, HCFCD Unit J100-00-00, between Interstate Highway 45 and Roberts Cemetery Road, and along about 32 miles of Cypress Creek, HCFCD Unit K100-00-00, from its confluence with Spring Creek to about State Highway 249.
UAS flights are especially useful in debris removal efforts along heavily wooded natural channels, where access for personnel and equipment is limited.
UAS over Brickhouse Gully
In July 2017, the Harris County Flood Control District used a UAS to conduct an infrastructure assessment along a 7-mile section of Brickhouse Gully, a concrete-lined tributary of White Oak Bayou formally identified as HCFCD Unit E115-00-00. A UAV operated by Michael Baker International, a licensed Flood Control District contractor, flew over and along Brickhouse Gully within Flood Control District right-of-way, from the gully’s confluence with White Oak Bayou upstream to Clay Road.
The UAS infrastructure assessment will be compared to those conducted by ground survey crews. Regularly assessments of Flood Control District property are necessary to efficiently and accurately study drainage infrastructure, to determine if replacement or repairs are needed.
UAS on Cedar Bayou
In June 2017, UAS sub-contractor InControl Technologies Inc. conducted an aerial environmental assessment of Harris County property near Cedar Bayou in northeast Harris County. Data and images were collected in connection with a Flood Control District project to evaluate creation of a wetlands mitigation site for the Cedar Bayou watershed. Cedar Bayou is formally identified as HCFCD Unit Q100-00-00.
A wetlands mitigation site is a protected area in which valuable environmental resources are created, restored, enhanced or preserved. In the future, this 240-acre site may be used to increase the amount of protected wetlands as a replacement for wetlands that will be impacted or destroyed by other projects elsewhere in this part of Harris County.
R.G. Miller Engineers Inc., project design engineer for the Flood Control District, was in charge of all field surveys and investigations, including UAS operations.
UAS on White Oak Bayou
In September and October 2016, the Harris County Flood Control District conducted its first test of UAS to measure and assess Flood Control District basins and drainage channel easements. Austin-based HUVRdata LLC, a Flood Control District contractor, flew over White Oak Bayou and three stormwater detention basins in central Harris County, roughly between Fairbanks North Houston Road and North Houston Rosslyn Road. After collecting more than 3,000 images and related data during two days in the field September 28-29, the company is now preparing its final report.
The contractor used an Ascending Technologies Falcon 8 to survey approximately 329 acres in the project area, measuring maintained vs. unmaintained areas, including some with tree cover. This is an 8-rotor, v-shaped Vertical Take Off and Land (VTOL) aircraft, which weighs less than six pounds. The use of UAS will be compared to the use of ground crews in performing similar measurements. Frequently updated measurements of Flood Control District property are necessary to the efficient and accurate management of contract maintenance services such as mowing, which are typically bid by the acre.
This area was chosen to test UAS capabilities over densely populated urban areas located directly adjacent to Flood Control District infrastructure.
UAS at John Paul’s Landing Stormwater Detention Basin
Flood Control District UAS contractor Precision Aerial Compliance Solutions conducted aerial topographic surveys at the Stormwater Detention Basin at John Paul’s Landing in northwest Harris County in 2016 and 2017. Data and images provided timely information about current conditions at the 283-acre site, where work progresses on a $1.8 million capital project to expand the stormwater detention basin. Quick completion of the topographic surveys helped avoid delays in the project, which began in 2015 and continued with a second phase in 2016-17.
The basin at John Paul’s Landing, located in a mostly rural area of the Addicks Reservoir watershed, is a key element of the Upper Langham Creek Frontier Program. John Paul’s Landing is the site of a future Harris County Precinct 3 park.
Stormwater detention basins reduce flooding risks and damages during heavy rain events by safely storing excess floodwater and slowly releasing it back to the bayou when the threat of flooding has passed.
(Photo at John Paul's Landing of Jason Nicholas, pilot in command, and HCFCD construction inspector Larry Rosenthal, courtesy of Precision Aerial.)