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Efficiently Planning and Building the Future of Moreno Valley, CA

Committed to Providing Development Plans for the City Consult Us

Efficiently Planning and Building the Future of Moreno Valley, CA

Committed to Providing Development Plans for the City Consult Us

Winchester Associates, Inc. PROFESSIONSL SERVICES

Winchester Associates, Inc. (WAI) is a multi-faceted professional land development firm providing civil engineering, land and environmental planning, land use entitlement, and land surveying since 1978. Our team includes members with professional licenses in Civil Engineering, Land Surveying, Storm Water Prevention, Storm Water Quality, and Law.

The WAI team has decades of experience performing professional land development related services for most types of residential subdivisions, multi-family residential projects, commercial retail and office, industrial, hotels / motels, airports, and RV parks. Additionally, WAI has specialized knowledge gained from work performed on past major projects requiring hydrology / hydraulics, earthwork, CEQA, reservoir design, and water and sewer infrastructure. WAI is uniquely qualified to assist its clients in the land development community not only because of our many years of experience as civil engineers, land planners and surveyors, but also because WAI invests in its employees and encourages each of them to continue their professional development. David Slawson is both a Professional Land Surveyor and an Attorney at Law, previously served 7 years as a City of Moreno Valley Planning Commissioner and currently serves as an elected member of the Board of Directors of Eastern Municipal Water District (EMWD), as a Commissioner on the Western Riverside Council of Governments (WRCOG), and as an alternate Commissioner on the Santa Ana Watershed Project Authority. Mariela Anguelov holds a California license in civil engineering, is certified as both a Storm Water Pollution Prevention Plan Practitioner and Developer, and is certified as a Professional in Storm Water Quality. Daniel Slawson is a Professional Land Surveyor and serves as an elected member on the Beaumont-Cherry Valley Water District.


Civil engineering Design

WAI has provided professional civil engineering, land surveying, and land planning services for both public and private entities for over 30 years. While most of our projects have been within the City of Moreno Valley, WAI serves all of the surrounding southern-California communities.

Besides providing the private land development communities with professional services, WAI has performed engineering design and surveying for many public agencies. Public agency clients have included the Cities of Banning, Hawthorne and Moreno Valley, and the Elsinore Valley Municipal Water District. Public work has included numerous street designs and specifications, site grading plans, storm drain design, topographical and boundary surveys, construction surveying, and studies for hydrology, hydraulics, water quality management and water reservoir site design. WAI has also been pre-qualified by the County of Riverside Economic Development Department to provide professional civil engineering and land surveying services to the County of Riverside. At WAI we pride ourselves with having successfully worked on some of the most significant, cutting-edge, mixed-use land development projects in western Riverside County. We have also provided highly technical expertise on projects requiring innovation and engineering precision. WAI is most proud to have been able, over the years, to provide pro bono engineering and land surveying services to numerous local civic, social, cultural, religious, and recreational groups.


representative list of clients

PLANNING, SURVEYING and LAND PLANNING WAI has prepared hundreds of tentative tract maps and prepared final
engineering plans for single family residential projects (R5 lots to
hillside development), ranging in size from 20 lots to 440 lots; prepared
preliminary/conceptual designs and final engineering designs for multi-family
residential projects in the thousands of units, and; prepared
preliminary and final designs for mixed-use, commercial, industrial, and
public projects.

Pacific Communities
Highland Fairview
Vintage Communities
Stratus Homes
Moreno Valley Elks
Moreno Valley VFW
Moreno Valley Youth Federation
Moreno Valley Equestrian Center
Moreno Valley Community Church
Professors Capital
Pacific Century Homes
Stronghold Engineering
Raytheon Corporation
Champion Homes
Fidelity Land Title Co.
Chicago title
First American Title
North American Title
Pacesetter Homes
Miller-Jones Mortuary
PLANNING, SURVEYING and LAND PLANNING Street improvement plans/specifications and construction surveying
Records of Survey
Public park and animal shelter grading plans
Grading designs for water storage tanks and access roads
Annexation legal descriptions and exhibits
Topographical surveys
Environmental assessments/Mitigated Negative Declarations
Major water and sewer line design and survey staking

City of Banning
City of Hawthorne
Elsinore Valley Municipal Water District
Tenaja Community Services District
Edgemont Gardens Mutual Water District
Eastern Municipal Water District

About Us


David Slawson

President, Winchester Associates, Inc. (WAI) (1979 – present)

Eastern Municipal Water District (EMWD) Division 5, Director (1995-present).

EMWD serves a population of over 800,000 residents, covers an area of 555

square miles and has a current operating budget of over $300 million.

Commissioner and current President, Santa Ana Watershed Project Authority(SAWPA)

(2004 – present) SAWPA is a JPA with WMWD, SBMWD, IEUA and OCWD

and manages the Santa Ana River brine lines.  

Executive Committee Alternate Member, Western Riverside Council of Governments

(WRCOG) (2013- present) JPA of the County and cities in western Riverside


Member on the Riverside Community College District Foundation Board (2017-

present). The Board oversees grants and scholarships for the RCC.


City of Moreno Valley RDA Oversight Commissioner (2012 to 2019). The

Commission manages the city’s RDA dissolution by approving ROPs.  

Board Member, State of California Department of Consumer Affairs’ Board of Registration for Professional Engineers and Land Surveyors(1991 – 1995)

Planning Commissioner, City of Moreno Valley (1986 – 1993) Actively participated in

the review and approval of all minor and major land use projects in the city.  

Professional Licensing

California licensed Professional Land Surveyor No. 4724 (1978)

California licensed Attorney at Law No. 259635 (2008)


British American University School of Law, Lake Forest, CA. Completion of Juris Doctorate program

UCR, Riverside, CA., Executive Management Program

UCR, Riverside, CA., Economic Development Management Program

California Coast University, Santa Ana, CA. Bachelor of Science, Management  


Special District Administration, Ca. Special Districts Assoc.

Practicalities of Running a District, Ca. Special Dist. Assoc.

Legal Descriptions and Survey Boundary Control, Gurdon Wattles

Boundary Surveys, American Congress on Surveying and Mapping Fundamentals of Water Supply Operations, Illinois E.P.A.


Daniel Slawson

Daniel is a California Licensed Land Surveyor, ACAD operator and civil engineering designer. Daniel manages Winchester Associates’ surveying division and is the vice president of land surveying. He is familiar with many of our local cities’ and special districts’ improvement design standards and has prepared street, water, sewer and grading plans. Daniel also prepares metes and bounds legal descriptions, prepares tentative and final parcel and tract maps, and performs boundary and construction surveying. He has been with Winchester Associates since 1992.

Daniel currently serves on the Board of Directors of the Beaumont – Cherry Valley Water District. He was first elected to the Board in 2012 and has successfully been reelected to 4-year terms since.

Daniel was raised in Moreno Valley and moved to Beaumont in about 2008, where he currently resides with his wife and daughter. He also attends the Toastmaster’s  Moreno Valley City Hall Club.


Mariela Anguelov

Mariela is the vice president of civil engineering for Winchester Associates. She received her 5-year Masters-equivalent degree in Civil Engineering / Hydrotechnical Construction from the University of Architecture, Civil Engineering and Geodesy in Sofia, Bulgaria,

Mariela is a California Registered Civil Engineer and a California Land Surveyor-in-Training. She is also certified as a Storm Water Pollution Prevention Plan (SWPPP) Qualified Practitioner and as a Qualified Developer, and is Certified as a Professional in Storm Water Quality (PSWQ). She is a member of the American Society of Civil Engineers. Mariela provides technical designs and has prepared numerous Water Quality Management Plans and hydrology/hydraulic studies.

Mariela is married and resides in Riverside with her husband, an engineer for RCFC.  Mariela also speaks English, Russian, and Bulgarian, has served many years as a docent for the Mission Inn in Riverside, is a docent for the Heritage House, is a regional president for Toastmaster’s International and attends the Toastmaster’s  Moreno Valley City Hall Club.

Our Services

To further help in the development of Moreno Valley, our team of civil engineers offers the following services:


Tentative Maps, Parcel Maps, and Record of Surveys are just some of our Land
Surveying services.

Land Surveying


We prepare Grading, Street, Sewer & Water, Erosion Control, and much more!

Civil Engineering


California Environmental Quality Act, Zone Changes, you name it, we can do it.

Land Planning


Our Civil Engineers are qualified to make Water Quality Management Plans.

Storm Water Quality

Contact Us

If you are interested, set up a consultation with us by filling out the form below. We look forward to hearing from you.

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