Northwest Park Dam Maintenance & Modernization Project

Overview

Previous inspections of the dam and regional detention facility have determined that the dam needs several heavy maintenance activities. Additionally, the dam needs to be modernized to meet State and City dam safety standards. The work is divided into three categories: Dam Safety, Dam Maintenance, and Park Drainage & Water Quality.

Dam Safety

These items will bring the dam into full compliance with State and City regulations to protect the structural stability of the dam. The items include tasks like:

• Adding overtopping protection to the top of the embankment
• Repairing erosion that has occurred on the creek side of the embankment
• Removal of woody vegetation on the embankment

Dam Maintenance

These items do not currently impact the stability of the dam unless they are left unaddressed for too long.  The items include tasks like:

• Protecting the embankment from erosive foot traffic within the Park
• Reinstalling drainage behind retaining walls
• Sealing cracks and joints within all retaining walls

Park Drainage and Water Quality

These items have no impact on the structural stability of the dam.  The items are dependent on the coordination with the Parks and Recreation Department and the Vision Plan that is currently being developed for the park. The items include tasks like:

• Reestablishing positive drainage near the tennis courts
• Reestablishing positive drainage near the duck pond
• Evaluating several ways to improve the water quality in the area

Background

Beverly Sheffield Northwest District Park has a dual purpose. During dry weather the area is a district park and during wet weather the area is a regional detention facility. The regional detention facility includes an earthen dam located between the district park and Shoal Creek. The dam and regional detention facility were constructed in 1986 to provide flood risk reduction to properties along Shoal Creek. During storm events, Shoal Creek rises and water enters the park near the tennis courts.  As the creek rises so does the water level in the park. The dam between the park and the creek helps decrease the amount of water flowing downstream in Shoal Creek. As the amount of water in the creek decreases, the water in the park will start to drain through two outflow pipes. One of these pipes is near the duck pond and the other pipe is near the south parking lot by the baseball field. The last part of the dam and regional detention facility is the auxiliary spillway that is located near the baseball fields. The auxiliary spillway is a designated overflow location for water to reenter the creek once the regional detention facility is full. This auxiliary spillway is only activated during extremely large storm events.

Regulations

Dams that are the size of the one at Northwest District Park are regulated by the City and the State, specifically the Texas Commission on Environmental Quality (TCEQ). These regulations help protect the dam and the structures that are located downstream of it.  These regulations include hydraulic requirements and standard rules on how a dam should be maintained. The dam is inspected regularly by TCEQ and WPD staff to ensure the dam is properly maintained.

Timeline

Our capital improvement projects take many years from start to finish. The process typically includes the following phases:

• Preliminary Engineering – when a solution is identified and costs are estimated.
• Design – when the details are worked out and construction plans drawn up.
• Bidding and Permitting – when a contractor is hired and all permits are acquired.
• Construction – when the project is built.

The project is currently in Preliminary Engineering with design estimated to begin in Fiscal Year 2024.

Questions?

• Robert Hermosillo, Project Manager, (512) 974-5634, Email Robert Hermosillo