Contributed by Andrea Harbin Monahan, Watershed Scientist, CWCB
The Left Hand Watershed Center (Watershed Center), which strives to maintain and improve ecological conditions and resilience within the watershed, is doing so with a strategy that should be adopted in all watersheds. It’s called Adaptive Management and a few of the scientists at the Watershed Center were kind enough to recently give me a tour of a couple of projects that highlight this method.
We met at their 63rd Street project site, donning face masks, and I was so thrilled to be outside and anywhere other than home. The scientists of the Watershed Center brought me to a restoration site that had numerous challenges. This section of Left Hand Creek is a confined, densely populated rural corridor, which posed many design challenges from the start. Restoration efforts initially repaired damage from the 2013 flood and improved bank and in-channel conditions. However, shortly following restoration, the site became overrun with significant weed infestations. Further, data collection efforts revealed that the site lacked sufficient pool habitat. Watershed Center staff described how this particular project benefited from an adaptive management approach through iterative data collection and monitoring.
For the Watershed Center, Adaptive Management means defining a goal, quantitatively tracking progress towards that goal via defined parameters, and adjusting management or monitoring actions iteratively based on what is learned, via defined “triggers” that require action. At 63rd Street, they were able to identify two monitoring parameters that triggered an action, and they subsequently adjusted their management and monitoring actions to improve the restoration outcome. The first parameter, plant composition, was addressed via additional weed control. After three years of management, they have a thriving reach where non-native vegetation is being kept at bay by more prolific native vegetation. The second parameter, pool habitat, requires the team to further investigate drivers (flow, sediment regime, scour mechanisms) to better understand why the site is not maintaining pool habitat year to year.
The next place they took me was collectively referred to as their favorite project site, which suffered from large volumes of deposited sediment following the 2013 flood, disconnecting the river from its floodplain and degrading aquatic habitat. Located east of Buckingham Park along Lefthand Canyon Drive, the Watershed Center is using adaptive restoration here, where they use restoration as an experiment. The upstream portion of the reach exhibits diverse restoration techniques and specifications, with varying bench heights, varying vegetation, groupings of plants with different traits, etc. The Watershed Center works with partners at CU Boulder and returns periodically to collect data and quantify the benefits of the diverse restoration approach, which they can then compare to the traditional restoration approach that has been implemented further downstream.
Given that the Adaptive Management approach has been so successful in the Left Hand Watershed, the Watershed Center is looking to expand that approach to neighboring watersheds. Their goal is to develop a framework that will help stakeholders make more informed management decisions within the larger basin and to better track broad progress towards basin-wide watershed health goals. They propose to do this by developing a framework in which to share data across watersheds to better understand what has been collected, where there is data overlap, and where there are data gaps. They’ll be able to work with their neighboring watersheds to document, research, and refine watershed health indicators and find ways to integrate existing watershed management plans and tools. Using Adaptive Management, the Watershed Center can iterate this process and update the framework based on what is learned.
What’s more is that the Watershed Center is actively engaging the next generation into this Adaptive Management framework by working with the Town of Lyons K-12 public schools to engage students with watershed data collection, data analysis, and place-based learning.
With such a dedicated team of scientists that are passionate about the resilience of the Left Hand and surrounding watersheds, I think the Left Hand Watershed Center has a lot to offer in terms of sharing meaningful approaches to obtaining healthy and resilient watersheds. The rest of us could definitely benefit from their example.