Services Provided: Civil Engineering, Storm Water Management, Land Planning
Project Description: Kayenta is located in northeastern Arizona, in the northern part of Navajo County, approximately 150 miles northeast of Flagstaff and 30 miles south of the Arizona-Utah border at the junction of US 160 and US 163. Wetherill Heights is a residential subdivision in old town Kayenta that consists of a network of dirt roads and one paved road. The subdivision generally slopes from the southwest at an approximate elevation of 5,780 feet MSL to the northeast towards the Kayenta Elementary School at an approximate elevation of 5,660 feet MSL.
The past development of this subdivision demonstrated little regard for the potential of flood hazards, which has increased the potential for flood related damage. To compound the problem, aeolian erosion has resulted in the deposition of loose friable soils within the subdivision. Vehicles traveling along the local roads have compacted this soil creating corridors for stormwater runoff. During heavy rain events, the local unimproved roads erode and transport material downstream to the school.
CVL has used the FLO-2D model to determine both the existing hydrologic and hydraulic conditions of this existing subdivision. Because the subdivision was already established, CVL needed to quantify the flows that were being conveyed around the existing homes and structures. The model revealed detailed flood inundation characteristics that were used to develop a comprehensive flood mitigation strategy.