The Enclaves at Mountain Vista

The Enclaves Mountain Vista is a 153-acre residential development offering an innovative, eco-friendly design in Colorado Springs, CO. This low-impact design (LID) subdivision includes 485 lots consisting of single-family and paired patio homes. Galloway provided full planning, civil engineering, and survey services for the first three phases of this multiphase project, including road construction, grading, retaining walls, bioretention, stormwater retention ponds, utility installation, and construction administration.

Due to the challenging terrain, Galloway provided innovative design solutions for the required stormwater detention. A low-impact development solution was implemented to utilize the existing sandy soils on the site, reducing the required detention volumes of the sub-regional detention pond. Small roadside bioretention cells were used to capture the water quality event volume, allowing it to infiltrate, while larger storms were managed through a traditional storm sewer system and piped to the sub-regional detention facility. Galloway worked closely with the City of Colorado Springs from concept to full implementation, as the City had never permitted such a large-scale LID.

In addition to the on-site LID system, Galloway designed a 7.5-acre-foot sub-regional detention pond to implement a master-planned detention facility, ensuring compliance with both the drainage criteria manual and the MS4 permit requirements. A master plan was prepared for the development, utilizing EPA-SWMM to model runoff for the site during multiple storm events. The model was used to account for the water quality event and to size the sub-regional detention pond due to the complexity of over-detaining on-site ponds in series.

Engineering services were also provided to construct three collector roadways with an inverted crown design, as well as the internal local roads. Galloway collaborated with the City of Colorado Springs and El Paso County to coordinate the timing of Marksheffel Road widening improvements and to address the impact of the widening on the proposed roadways. Galloway facilitated multi-jurisdictional solutions to challenges in roadway design caused by steep existing grades and existing oil pipelines within the development. Our team also provided design services for the development’s water and sewer infrastructure.

Galloway worked closely with the City of Colorado Springs to design and implement the bioretention cells, as LID on this scale had not previously been performed within the City. Once constructed, the LID will be owned and maintained by a Metro District for the development.