13th St Project Assessment

The FCWD project goals from their 2017 project assessment include:

• Erosion control to protect infrastructure, such as the 8th street bridge, nearby railroad, and surrounding roads

This is achieved by:

• Increasing the sinuosity (curvature) of Fountain Creek, which reduces creek velocity and slope

Our approach:

To better understand the performance of the 13th street restoration project we:

• Analyzed GPS data to generate elevation models of the area
• Utilized aerial imagery to create stream centerlines and bed profiles in order to assess channel migration over time

Based on the images above, we can see that Fountain Creek sinuosity has been maintained even after a 50-year flooding event.

Take Aways:

The project goals that were met include:

• Maintained sinuosity and low slope
• Decreased erosion and sediment displacement seem to be maintained
• Creek does not seem to hinder the surrounding infrastructure

Possible hazards:

The developing channel could become an active channel that causes increased erosion and sediment displacement. Future monitoring of this area could prevent possible negative impacts to surrounding infrastructure and FCWD project goals.

Increasing channel width is a sign of high erosion. Here, we will analyze channel width over time at the 13th Street project to see if has mitigated erosion

The movement of the creek channel can also be a sign of increased erosion and sediment deposition. Here, we will analyze how channel migration has had an impact on the 13th street project.

In addition to looking at aerial imagery, we also conducted an onsite survey of the site that brought to light additional success and some possible areas of concern.

From aerial image analysis, onsite observations, and GPS data, we were able to make an extensive assessment of the 13th street project and identify major achievements as well as possible areas for further monitoring and upkeep. We concluded that both the creek width, and channel migration of the creek, have been relatively stable after project instillation. Not only that, but they have held up quite well even after the 2023 Floods. Additionally, we can see a majority of project netting is still in place, and vegetation is taking root in these areas, all of which is increasing the stability of the site. This all speak to the success of the project, and show that it is indeed meeting project goals.

However, we also noticed a developing channel forming in the northwest embankment of the project, that was most likely formed during the 2023 flooding event. Currently, the channel has no fluid running through it and poses no threat to the project. However, over successive flooding events, it could further develop into a permanent channel. Due to its higher slope and reduced sinuosity, it could increase erosion and sediment deposition, which could hinder project goals. We can already see some of the consequences of this through the displacement of rip rap across from the mouth of the developing channel.

Overall, the project is doing quite well, and it is meeting project goals. However, the possible development of a new channel could hinder these goals. Due to this, the creek should be monitored, especially after future flooding events.