By Josh Pike
In terms of protections, not all wetlands are created equal. The downtown Pagosa Springs Wetlands deserve enhanced town protections because of their proximity to downtown commercial and residential activity, the complex and fragile nature of their warm water inflows and their central role in the social fabric of Pagosa Springs. These characteristics make our Riverwalk Wetlands extraordinarily unique as wetlands go and worthy of our collective stewardship.
It is the town’s Land Use Development Code (LUDC) that defines and sets limitations on building near flood plains and wetlands. The implementation of setbacks or buffers to protect wetland areas from the impact of nearby development are prominent among the environmental protections being considered in the current LUDC revision process. This article explores the purposes and benefits of setbacks, with the aim of better informing the citizens of Pagosa Springs about this central environmental protection measure.
Setbacks are designated areas of vegetated space around the edges of a wetland where development cannot occur. This space provides a buffer for wetland wildlife from the disturbances and pollutants introduced by human development. Setbacks are a simple and widely used wetland protection measure that appear in municipal codes nationwide.
Setbacks provide three main kinds of protection to wetland wildlife: 1) protection from pollutants, 2) protection from invasive species and 3) protection from nearby disturbances. Areas of human development are rife with potentially hazardous substances, from vehicle fluids and exhaust residues left on pavement to the nutrient dense fertilizers used in landscaping. These substances run off the largely non-absorbent surfaces of a development and into the surrounding environment.
Setbacks provide protection from these substances by slowing and filtering the flow of harmful runoff before it reaches nearby wetlands. The soils and plants present in a setback area absorb much of the water, allowing the chemicals in it to be deposited in the setback region before they can reach the wetland. Additionally, substances such as the phosphorus and nitrogen used in fertilizers are often taken up and used by the plants in the setback, preventing them from reaching the wetlands where they can cause devastating algal blooms. Research has shown that these pollution protection benefits typically require setback zones of approximately 100 feet, although low soil stability and vegetation density or steep slopes can raise this distance substantially.
Another function of setbacks is protecting wetlands from biological contaminants such as invasive species. Many invasive species thrive in highly disturbed environments, such as the margins of parking lots and roadways, and can easily spread from there to nearby environment. However, setbacks create a barrier of healthy indigenous vegetation between these invasive rich areas and critical environments like wetlands, mitigating the spread of invasive species.
Additionally, setbacks benefit species native to the wetlands, many of whom rely on the edges of the wetland habitat for feeding and nesting. Setbacks ensure that these ecologically rich transition zones out of the wetlands continue to exist, thus ensuring the health of the wetland species that rely on them. While the setback areas necessary for biological protection depend on species, a minimum setback of 300 ft. is a commonly used distance for this type of protection in municipal codes.
Setbacks also and provide wildlife habitat and protection from the disturbances inherent in human development, including the sounds of vehicles, human activity and the presence of their pets, building heating and cooling systems and the disturbances of artificial lights at night. The vegetation in the setback provides a screen for wetland wildlife from these disruptions, mitigating their intensity and the negative impacts that such regular disturbances can have to the daily activities and reproductive behaviors of wetland species. The amount of distance required for this kind of protection is highly variable, depending on both the species involved and the intensity of nearby activity. However, setbacks of 200 – 300 ft. are commonly used for this purpose.
The specific implementation of setbacks can take many forms. Setback distances can be fixed or can be dependent on the intensity of nearby development. Many different regulations exist in terms of whether stormwater detention features or other tools may be placed in the setback area. Additionally, the means of enforcing and regulating setbacks varies widely, depending on the specific infrastructure and policies of the municipality.
Setbacks are a common wetland protection tool because they are simple to implement, understand and are proven to work in the wide range of municipalities that have used them. Additionally, they place a low burden on developers, who often find them beneficial for enhancing the natural vistas surrounding their developments and effectively utilizing land near wetlands that is otherwise too unstable or flood prone to be useful. Setbacks are also a key tool for towns and counties looking to expand their environmental stewardship, as setbacks provide protections otherwise not present in state or federal environmental protections.
The downtown wetland setbacks being considered as part of the Pagosa Springs LUDC revision, would provide science based protection for our local wetlands while fostering sustainable development in our community. They are an excellent step on our community’s path to preserving the natural beauty of our town for locals and visitors in the years to come.
If you want to learn more about wetland protections or get involved in protecting our downtown Riverwalk Wetlands, please contact Pagosa Wetland Partners at pagosawetlands@gmail.com. Additionally, guided naturalist tours of the Riverwalk Wetlands are offered at on Fridays and Saturdays at 8am and Tuesdays at 7pm every week starting at the Audubon Native Plant Garden in Centennial Park.
We look forward to learning about and preserving our local wetlands together.
Josh Pike writes on behalf of Pagosa Wetland Partners.