Innovatively addressing flood recovery and building true resiliency through the integration of ecology and biodiversity in Colorado, USA
The Emergency Watershed Protection (EWP) Program was created to facilitate recovery from Colorado’s costliest natural disaster to date – devastating flooding in 2013 that affected 14 watersheds and caused approximately $4 billion in damage to infrastructure as well as public and private property.
Ramboll’s project team served as the lead restoration ecologists for the EWP technical assistance team.
Watershed flood recovery: background & guiding principals
The 2013 floods overburdened streams, which exceeded their channels and reconnected to historic floodplains, destroying roadways, homes, businesses and critical infrastructure. While early disaster recovery efforts re-opened transportation corridors, this came at the expense of river functionality, causing dysfunctional alignment, flow regimes and channel morphology.
Numerous municipalities and local watershed coalitions came together to address the restoration of flood-impacted areas.
The Ramboll project team focused on holistic participation within multi-disciplinary teams to innovatively address flood recovery challenges and build true resiliency. Project criteria uplifted ecological functions through analysis of hydrology, hydraulics, sediment transport and accumulation, and ecological reference areas in comparison to impacted project sites by examination of microsite, habitat and species richness to improve ecological complexity. We also led the river design and implementation for the North Apple Valley project.
Between 2015 and 2019, 117 flood projects were successfully completed with total construction costs of over $70 million, which avoided $270 million of short-term damage.
65 miles of river and floodplain improvements were implemented, 12 watershed master plans were finalised, 34 resiliency planning studies were completed, 23 comprehensive recovery planning studies were completed, and over 700 private property owners were engaged.
A total of 70 site-specific native plant species were included within project restoration efforts. Of these, approximately 65% represent woody taxon, 29% graminoid taxon and 6% herbaceous dicots (forbs).
A total of 60,000 dormant woody cuttings, 143,000 large containers (0.7-1 litre) and 83,000 plugs (0.2 litre) were utilized for restoration. Over 2,200 kg of native seeds were incorporated into the project revegetation.
- Increased species richness helps to preserve ecological functions and services, such as resiliency, biodiversity, and improved habitat, forage and refugia.
- Incorporation of green infrastructure with traditional grey infrastructure provides improved resiliency through improved ecological flexibility.
- Incorporation of green infrastructure is shown to improve mental and physical health through improved life quality and well-being.
- Incorporation of plant species provide for increased oxygen and help to sequester carbon dioxide.
- Incorporation of plant materials help to reduce overall nitrates, phosphates and turbidity in water, thereby improving water quality.
Sustainable Development Goals addressed
3 Good health and wellbeing