

Douglas J. Nicholls, PE, RLS, founded Core Engineering Group, PLLC (Core) in February 2004. In the years since, he has surrounded himself with talented colleagues and an impressive roster of collaborative firms. This includes the 2024 acquisition of James Davey and Associates, Inc. (JDA). JDA is a strong Yuma firm, founded in 1992, providing civil engineering, survey services, and construction inspection/construction administration. This team has established Core as a pre-eminent provider of civil engineering and land surveying services.
Core’s technical expertise is extensive. Our experienced staff is well-positioned to tackle any civil engineering or land surveying project, and diverse examples of our successful work are visible throughout Arizona, Southeast California, and Mexico. Transportation
• Project management
• Roadway design
• Traffic engineering
• Right-of-way
• Surveying
• Corridor design/DCR
• Signing and pavement marking
Utilities
• Southwest Gas
• Allo Fiber
• Century Link (Qwest Communications)
• Arizona Public Service
• Solar Energy
Public Works
• Project management
• Document and plan preparation
• On-call consulting
• Intergovernmental collaboration
• Utility coordination
Private Development
• Site design
• Subdivision platting
• Master planning
• Zoning
• Paving and grading
Water Resources
• Stormwater pollution prevention plan
• Water supply, treatment and distribution
• Sanitary sewer systems
• Irrigation and drainage
• Groundwater
• Hydrology/hydraulics
• Storm drainage facilities
• Area drainage plans
Survey
• All levels of design survey
• Project control
• Right-of-way determination
• Boundary and topographic survey
• ALTA survey
• GPS and topographic surveys
• Construction staking
Mr. Nicholls provides a comprehensive approach to designing projects and meeting quality standards in process, procedure, and criteria. He has over 30 years of engineering experience and is responsible for civil engineering design, personnel and resources, project management, and project quality, timeliness, and performance. This commitment is strengthened by his personal activity within projects. It is with this personal interest the Core Team will approach tasks assigned.
Mr. Davey has been intimately involved in the planning, design, construction, operations and maintenance of civil projects for over 40 years. He brings a strong public works, roadway and drainage, and detailed design and construction background. Mr. Davey has overseen the successful completion of projects including the planning, study, design and construction of arterial streets and freeways, major water and sewer projects and major storm drainage master plans.
Mr. Lopez has 24 years of civil engineering experience including civil design, site development, pavement designs, retaining wall design, pathway design, sewer collection systems, sewer lift station design, sewer force main systems, stormwater control design, and erosion and sediment control design. He oversees the day-to-day operations of all civil and transportation projects and coordinating design disciplines.
Mr. Sanchez has 22 years of civil engineering experience includes survey, civil design, and construction administration. He has provided engineering services to both public and private clients, including municipalities, local and state government agencies, special districts, utility companies and land developers.
Mr. Johnson has 17 years of experience including research and determination of boundary information, delineation and documentation of new right-of-way, design-level surveying and construction staking for residential, commercial, and municipal developments.
ADOT, Area Service Highway – General Plan & Segments 3, 5, and 6
• New 24-mile-long controlled access freeway.
• 4-lane facility.
• New right-of-way and utility relocations.
• Estimated project cost $76M.
ADOT, US 95 Expansion in Yuma County
• Design support for 2 segments
• Highest volume 2-lane state road
• Expansion to 4 lane facility
• Subconsultants to primes
• Survey and irrigation design
City of Somerton, Somerton Avenue / Jefferson Street Intersection Realignment
• New roadway Jefferson Street (Somerton to Carlisle Avenues).
• Drainage design.
• Street lighting.
• Utility relocations.
• Right-of-way acquisition.
City of Yuma / Yuma County, 40th Street –Avenue 6E to Fortuna Road
• 4-lane roadway with medians, 5-miles long, box culvert crossing
• Corridor design/DCR (Interim and Ultimate)
• Grade Separate Crossing of SR-195
City of Yuma, 16th Street and 4th Avenue Reconstruction Expansion
• 3-lanes in each direction and dedicated turn lanes
• Redevelopment of area to Center Point
• Regional Drainage Basin
• Utility and right-of-way coordination
• Highest volume intersection in region
City of San Luis, Cesar Chavez Boulevard Expansion
• Interim intersection and spot improvements
• Right-of-way delineation
• 2 miles widening to 5-lane roadway
• Survey support
• Corridor Drainage Analysis