Colorado License #PE.0060665 · 7,000+ Projects Delivered · Free Assessment

Grading & Drainage Plan Engineering

PE-stamped grading and drainage design that protects your foundation, satisfies your reviewer, and manages Colorado stormwater the way your jurisdiction requires.

Call for a Free Quote: (888) 305-3967

Why Colorado Cities Reject Grading Plans — and How We Prevent It

Grading and drainage comments are among the most common plan-review corrections in Colorado. Reviewers look for positive drainage away from foundations, no adverse impact on neighboring properties, compliance with the jurisdiction's drainage criteria, and in many cities, stormwater detention for added impervious area. Plans drawn without the local criteria — or without an engineer's stamp where one is required — get bounced, and every bounce costs a week or more. We prepare grading and drainage plans that pass: existing and proposed contours, positive drainage with slopes and flow arrows, foundation protection details, and stormwater management engineered to your city's standards. Many Front Range jurisdictions follow Urban Drainage and Flood Control District (UDFCD) criteria — we work in that framework daily.

Residential and Commercial Drainage Problems We Solve

• Water draining toward or pooling at foundations — the top driver of expansive-soil damage along the Front Range • Downspout and sump discharge problems — concentrated discharge that erodes soil and loads adjacent drains • Negative grading — yards that slope toward the house • New impervious area — additions, ADUs, and paving that trigger detention or drainage review • Drainage disputes between neighbors — engineered documentation of existing conditions and corrective design • Erosion and sediment control — SWMPs and BMP plans for sites disturbing ground • Detention and retention — sized per UDFCD or local criteria where your city requires it Drainage engineering isn't just about passing review — on Colorado's expansive soils, keeping water away from the foundation is the single most effective thing you can do to protect the structure.

What Your Plan Set Includes

Depending on your project and jurisdiction, your package can include: • Existing and proposed grading plans with contours and spot elevations • Drainage plan with swales, flow arrows, and discharge points • Positive-drainage details at the foundation (typically 6 inches of fall in the first 10 feet) • Downspout and sump discharge routing • Detention/retention design with sizing calculations where required • Erosion control plan and BMPs • Drainage letter or report where the jurisdiction requests one • Structural calculations and the PE stamp We match your jurisdiction's submittal format — plan sheets, report, or both — and address reviewer comments at no additional cost.

Costs and Timeline

Simple residential grading/drainage plans typically run $500–$1,500. Projects requiring detention design or a full drainage report run more. Turnaround is typically 2–5 business days. Call (888) 305-3967 with your address and project scope — we'll tell you what your city requires and quote it directly.

Grading & Drainage Plans — Frequently Asked Questions

Do I need a grading and drainage plan for my addition or ADU?

Many Colorado jurisdictions require one when a project adds impervious area or alters site drainage — rules vary significantly by city. Denver, Aurora, and several Front Range cities are strict; smaller towns are often lighter. Call us with your address and we'll tell you what your jurisdiction requires before you spend anything.

What is positive drainage?

Positive drainage means the ground slopes continuously away from your foundation — Colorado jurisdictions typically require about 6 inches of fall within the first 10 feet. It's the most important drainage feature on any property: without it, water ponds at the foundation and drives the expansive-soil movement that cracks Colorado slabs and basement walls.

What is a drainage letter or report?

A drainage letter is an engineer's signed statement documenting a site's existing and proposed drainage and certifying the design meets local criteria. A full drainage report adds calculations and analysis. Many Colorado jurisdictions require one of the two for additions, ADUs, and commercial projects — we prepare both.

How much do grading and drainage plans cost?

Simple residential plans typically run $500–$1,500; projects with detention design or a full report run more. Call (888) 305-3967 with your project scope for a firm quote — the phone assessment is free.

Can you help with a drainage dispute with my neighbor?

Yes. We document existing drainage conditions, analyze how water moves between the properties, and provide an engineer's report identifying the cause and the corrective design. Our reports are used in neighbor negotiations, HOA disputes, and legal proceedings.