NPS Maricopa Inc. - Civil Engineers

NPS Maricopa Inc. - Civil Engineers
An Arizona Nonprofit Corporation since 2017
MESA AZ 85201-3933


NPS Maricopa Inc. is a registered Arizona civil engineering firm with particular expertise and experience in:

About NPS

NPS Maricopa Inc. is a member of the self-managed family of engineering companies founded by Tom Haws (currently including NPS Pinal Inc. and NPS Agua Fria Inc.) that comprise a successfully exciting experiment in the following organizational foundations:


Tom Haws

Thomas Gail Haws graduated from Brigham Young University in Utah with a Bachelor of Science in civil engineering in 1991. He has been a registered civil engineer in the State of Arizona since 1996 with a special focus on flood control. He was born in Mesa, and he has practiced mostly in central Arizona starting with subdivision drainage reports and water system mapping and through the decades including paving; grading and drainage including watershed studies (HEC-1, SWMM, and DDMSW), erosion protection, and scour calculations; water plans and models (EPANET); sewer line plans and models, treatment plant elements, and lift station plans and models; flood irrigation plans and models; and floodplain revisions and certificates (HEC-RAS 1D and 2D) for large and small subdivisions, single homes, roads, utilities, and commercial, government, utility, and mining sites. He is also a programmer (including for AutoCAD and the LAMP/JS web stack), blogger, and vocal musician/arranger/composer.

Juan Reyes

Juan Reyes is a registered civil engineer in the State of Arizona and the State of Missouri with 14 years of experience. He graduated from Arizona State University with a Bachelor of Science in Engineering in 2006. He has practiced civil engineering from the west coast to the midwest, including in the states of Arizona, California, New Mexico, Missouri, Tennesse and Kentucky. He is civil engineering with a broad background, in the office and on the construction site. Experience includes Water, Wastewater and Stormwater systems design and construction administration. An Engineer with a profound understanding of the collaborative teamwork required to successfully deliver successful projects.

Mary Cabais

Mary Josette Manahan Cabais is a Filipino registered civil engineer with 15 years of experience. She graduated from Mapua Institute of Technology in Intramuros, Manila Philippines with a Bachelor of Science in Civil Engineering in 2004 and National University in Sampaloc, Manila Philippines with a Bachelor of Science in Sanitary Engineering in 2013. She is currently on her Thesis of Master of Science in Sanitary Engineering. She worked in Airport Infrastructure and Civil/Building projects as Assistant Quantity Surveyor in Dubai and AbuDhabi, UAE for 2 years. Working in a different culture and people was a tremendous experience for her. She joined a different private company and non-government organization, Philippine Red Cross for 7 years. She has experience in residential, commercial, and subdivision detailed engineering design such as roads, stormwater drainage, sewerage, water (EPANET), hydrology and hydraulics (HEC-RAS 1D and 2D), and wastewater treatment plant. Also, she became a Hydraulics, Hydrology, and Fluid mechanics professor in Pamantasan ng Lungsod ng Valenzuela from 2015 to 2016. In 2016, She started freelance work across Australia, Hawaii, and local projects. She has experience in the following software: AutoCAD, Civil 3D, Hydra flow storm sewers, and storm and sanitary analysis, Bentley ProjectWise, HEC-RAS, Hydro CAD, Epanet, and HY-8. She was hired by Tom Haws in 2018 via Upwork as Flood Control Civil Engineer-Freelancer in NPS Maricopa. An extraordinary woman who balances work and family. Mary loves music, swimming, biking, hiking, and traveling with family.

Dario Di Nunzio

Dario Di Nunzio is a registered civil engineer in Italy. He has a Bachelor’s degree in Civil Engineering, a Tier 1 Specializing Master in “GIS for Territory Governance” and a Postgraduate Master in “Energy Management”. In 2008, some months before obtaining his bachelor's, he completed a full internship at a local municipality where he got direct experience supporting the Head of Technical Department. After obtaining his registration with the Order of Engineers in 2010, he started working in the Photovoltaic and Wind industry as a GIS Technician and designer, where he developed his skills with AutoCAD, Civil 3D, QGIS and ArcGIS. At the same time, he started freelancing activity working mostly in South-Italy for rehabs, territorial analysis, drainage studies, structural calculations, GPS/GNSS and drone surveys, cadastral permits and firefighting systems. Soon, Dario also gained interest in 3d modeling/renderings and later in BIM modeling, skills used in combination with Civil 3D during a short period of work in the Netherlands. After some years as Project Manager in the renewable energy industry for a few different private companies in Italy and the UK, Dario joined NPS Maricopa in 2018. Always seeking for new training courses and updates, he likes to improve his skills and he dedicates part of his weekly spare time to these purposes. Indeed, he gained basic knowledge of Python, HTML and Javascript programming languages through online courses. Dario has several hobbies including swimming, jogging, and RTS games.

Julius Barcena

Julius Barcena is a Filipino registered civil engineer since 2008. He graduated from Ateneo de Davao University in 2007 with a Bachelor of Science in Civil Engineering. He started his career in a local design and construction company as a designer, drafter, and project engineer. After a year, he tried teaching part-time in his alma mater. In 2010, he entered the hydropower industry as a junior hydrologist. During his 8 years in this multi-national company, he honed himself with surface water hydrology, hydrologic and hydraulic modeling, hydropower and water supply simulation, and optimization. In 2016, he ventured into short-term projects involving river modeling, hydrology, stormwater management, and civil design to residential, commercial, and industrial developments across the US. In 2018, he joined NPS, seeking new perspectives and friends. His core expertise lies in hydrology, 1D/2D HEC-RAS modeling, hydrologic modeling using HEC-HMS and SSA, and stormwater analysis and management. Julius enjoys gardening, business, crime stories, and Japanese manga. He also has a humble fruit farm.

Paige Brue

Paige is a registered civil engineer/professional engineer (P.E.) in the State of California and a Certified Floodplain Manager (CFM). She has been working in the field of stormwater management and drainage engineering since 2012. Paige’s expertise lies at the intersection of the built environment and the natural world. She has been involved in a variety of projects throughout her career including highway drainage projects, hydraulic modeling for dams and spillways, stream stabilization, floodplain mapping, fluvial studies, environmental compliance, stormwater best management practice (BMP) design, and watershed planning. Paige holds a Master of Science (M.S.) degree in Biological and Agricultural Engineering from North Carolina State University and a Bachelor of Science (B.S.) degree in Environmental and Natural Resources Engineering from Purdue University with a Minor in Soil Science. In her free time, Paige enjoys running, surfing, hiking, reading, gardening, and traveling with her husband.

Plamen Dimov

Plamen Krassimirov Dimov is a registered civil/structural engineer in Bulgaria. He graduated with a Bachelor degree in structural engineering and a Master’s degree in hydraulic structures in 2014. His professional experience in Bulgaria includes working for a few companies in the private sector, and for a government engineering firm that works in the mining industry. Many of his fundamental CAD skills and overall engineering software capabilities were developed by self-education. Shortly before working for NPS Maricopa, Plamen also worked with a Canadian company, developing grading models in Civil 3D. It was in April 2017, when Plamen was hired by Tom Haws via Upwork that he started using his potential to the maximum, as his previous working employers only utilized a small share of his skill set. He is also interested in a few art forms: composing and playing music (electric guitar) and drawing, but engages in these activities as hobbies.

Sam Wachira

Samuel Wachira is an engineer-in-training (civil/structural) in Kenya. He graduated with a Bachelor of Science in Civil Engineering degree in 2015. Before graduating, he interned at a water and sewerage treatment company where he helped in maintaining daily operations and carrying water quality tests. Also, he interned at the Ministry of Lands, Housing and Urban Development where he assisted in carrying out structural and infrastructural design and supervision. Since graduating in 2015, he’s worked for a renowned private firm in Kenya for 6 years. He’s worked on institutional, government, residential and commercial projects. He’s proficient at using Civil 3D, AutoCAD, Revit Structure, Robot Structural Analysis, HEC-RAS, and HY-8. His design experience encapsulates watershed analysis, retention calculations, flood-limits analysis, grading and drainage, scour calculations and soak-pit (dry well) design and 2d flow-modeling. It was in April 2017, when Samuel was hired by Tom Haws via Upwork. This presented an opportunity to harness his huge potential and expand his horizon in the practice of civil engineering. He loves basketball, swimming, traveling and won’t pass up a chance to make acquaintance at opportune moments.

Ashwin Shrestha

Ashwin Kumar Shrestha is an engineer-in-training in Nepal. He graduated with a Bachelor's degree in Civil Engineering in 2015. He completed his final year project in structural design before graduating. He worked for two private hydropower firms for the next three years as a site supervisor as well as design engineer where he harnessed his skills on quality control in sites and design and drafting of hydropower components. Since 2017 he started working on grading and drainage design projects for a private company in Kathmandu where he developed his skills with Autocad and Civil 3D. Recently, he has started taking basic online courses in Javascript, HTML and Python. During spare time, he loves to travel with friends and family, watching movies and series, preparation of sketch drawings and playing video games.

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