Start at the roof
Consider the roof material and condition, catchment area, gutters and downspouts. Screens and debris control keep larger material out; first-flush management may divert the initial wash-off.
INTEGRATED WATER & LANDSCAPE PLANNING
Every water source.
A considered purpose.
Rainwater harvesting and graywater reuse can become part of how a landscape works. Start by understanding where water comes from, where it can go and what the site can support. Soil-building and soil-management practices are part of that picture.
01 / ACTIVESave it
Save it
for later.
Collect roof runoff in a tank for a planned nonpotable use.
COLLECT · STORE · USE02 / PASSIVELet the land
Let the land
do its part.
Shape the site to slow, spread and infiltrate rainfall where suitable.
SLOW · SPREAD · SOAK03 / GRAYWATERGive water
Give water
a second use.
Route suitable household graywater to carefully planned landscape irrigation.
SEPARATE · DIVERT · IRRIGATE
01 / ACTIVE RAINWATER HARVESTING
Roof to tank.
Tank to landscape.
Active systems collect and store rainwater so it can be used after the storm has passed. Roof catchment is one starting point; the collection surface, storage and intended use all shape the design.
Untreated roof runoff is not drinking water. It can pick up debris and contaminants. This active-harvesting concept focuses on nonpotable landscape use. Drinking-water goals need a separate potable-feasibility evaluation; treatment must fit the source and intended use.
County rainwater planning resourcesStore with a plan
Size storage around seasonal rainfall and landscape demand. Plan for a covered tank, protected openings, maintenance access and an overflow route for storms that exceed capacity.
Match water to use
Choose filtration and any treatment for the intended use. Gravity or a pump can deliver water to appropriate irrigation; drinking-water plumbing must remain protected from cross-connections.
Keep it working
Include a practical inspection and maintenance routine for the catchment, screens, tank, equipment and overflow. Storage is useful only when it can be operated and cared for.
02 / PASSIVE RAINWATER HARVESTING
Make the landscape
part of the system.
Passive systems use landform and planting areas to hold rainfall near where it falls. Instead of storing water in a tank, the design manages its path through the site and into suitable soil.
Infiltration is a site-specific choice. Soil, slope, foundations, utilities, setbacks and onsite wastewater areas can limit where it belongs. Some sites need a different approach.
County rain-garden guidanceWork with the contours
Thoughtful grading can direct appropriate runoff toward landscape areas while preserving drainage away from buildings and respecting neighboring property.
Create places to pause
Swales, shallow planted basins and rain gardens can slow and temporarily hold runoff. Soil conditions, contributing area and planting choices guide their location and form.
Design beyond the usual storm
Every capture area needs a considered overflow path. Plan where water goes when the soil is saturated or a storm exceeds the feature's capacity.
03 / GRAYWATER LANDSCAPE IRRIGATION
A separate source.
A useful second life.
Graywater is household water from suitable sources such as showers, baths, bathroom sinks and clothes washers. It is distinct from rainwater and excludes toilet wastewater, kitchen-sink water and dishwasher discharge.
Nonpotable and source-specific. A graywater system needs a separate, properly identified route to an approved use. It must not create a cross-connection with drinking-water plumbing.
San Diego County graywater guidanceRiverside County graywater guidanceChoose appropriate sources
Keep unsuitable wastewater and harmful household products out. A planned diversion back to the sewer or septic system is important when water is unsuitable for irrigation or the landscape cannot accept it.
Design for the landscape
Match distribution to suitable plants, soils and irrigation demand. Local guidance calls for subsurface dispersal that avoids spraying, ponding, runoff and contact with people or pets.
Coordinate the whole site
Account for buildings, property lines, wells and onsite wastewater infrastructure. Graywater does not eliminate the need for a compliant wastewater system.
Confirm the local path
Rules depend on the system and jurisdiction. Some narrowly defined clothes-washer systems may qualify for permit exemptions; other systems require review and permits. Confirm requirements before design or installation.
SOIL BUILDING & SOIL MANAGEMENT
Care for the ground.
Support the landscape.
Water planning begins beneath the surface. Soil structure, compaction, drainage and existing vegetation help determine what a landscape can support and which practices make sense.
Different soils, different jobs. Landscape soil-health practices are separate from structural-fill specifications and onsite wastewater absorption-area design. Each needs its own evaluation and appropriate professional review.
USDA soil-health principlesUniversity of California landscape guidanceUnderstand before changing
Assess soil condition, drainage and compaction, with testing where needed. Soil-building is a site-specific process, not a standard amendment recipe or a promised infiltration rate.
Protect structure and cover
Limit avoidable disturbance and compaction in planting areas. Choose suitable surface cover and organic matter where appropriate, accounting for plant needs and site constraints.
Let roots play their part
Use appropriate vegetation and rooting patterns to support landscape soil function and help protect against erosion. Coordinate planting with water availability, utilities and required clearances.
Keep soil in place
Pair soil care with erosion protection and a clear runoff plan. Amendments and planting cannot substitute for drainage, slope stability, engineered fill or a compliant OWTS design.
POTABLE RAINWATER FEASIBILITY
A drinking-water goal.
A rigorous path.
Interested in using roof-captured rainwater for drinking water? Start with feasibility: the site, intended use, water quality, dependable supply, treatment and the local approval path.
Capture alone does not make water potable. Roof runoff needs a separately evaluated drinking-water system. Graywater remains a distinct, nonpotable source and is not part of this drinking-water concept.
Evaluate the source
Review roof and collection materials, surrounding contamination sources and expected water quality. A clean-looking roof or clear water is not proof of safety.
Build in appropriate barriers
Assess source protection, first-flush management, filtration and disinfection as a coordinated system. Testing, maintenance and operating procedures need to match the actual risks and intended use.
Plan through the dry season
Compare seasonal collection with demand, usable storage and drought conditions. Any backup supply and plumbing connections need their own protection and approval.
Confirm the path before promising it
Coordinate applicable engineering, specialist design and agency review early. Australian experience can inform the approach, but California approval is project-specific. Approval, year-round supply and independence from other water sources cannot be assumed.
KEYLINE-INFORMED SOIL & WATER DESIGN
Read the terrain.
Plan the connections.
Keyline-informed planning looks at the relationship between landform, water, soil and vegetation. The useful starting point is a careful reading of ridges, valleys, slopes and existing drainage.
A design lens, not a standard prescription. Classic keyline cultivation works off contour; it is not the same as a level swale. Australian precedent does not replace California site evaluation, engineering or local approvals.
Let the terrain lead
Consider how grading, access, planting and water movement fit together. Locate storage and use gravity where the site can safely support them, while maintaining controlled overflow.
Focus on the root zone
Coordinate suitable planting, soil cover and soil-management practices with the pattern of water availability. Root-zone moisture is a planning consideration, not a guaranteed outcome.
Adapt with care
Check geology, slope stability, soils, utilities and wastewater constraints before proposing earthwork or cultivation. No blanket ripping, diversion or infiltration strategy belongs on every property.
PUTTING THE PIECES TOGETHER
One site plan.
Distinct water systems.
Think together.
Keep the sources clear.
A tank can supply planned irrigation while a separate rain garden manages suitable runoff. Graywater can serve another defined landscape area. Their location, demand, overflow, soil conditions and maintenance should be considered together, without casually mixing sources.
We begin with site-level feasibility and civil coordination, from landscape capture to separately evaluated potable-rainwater goals and terrain-informed design. Final design may also require plumbing, treatment, landscape or other specialists and approval from the responsible local agencies.
Discuss water on your siteFURTHER READING
Grounded in local guidance.
These are planning concepts, not installation instructions. Current local requirements and site conditions govern the final approach.
LOCAL PRECEDENTS
A longer story of water.
Explore Point Loma’s rain catchment and other Southern California water systems, with historic practice distinguished from present-day engineering.
Read the water heritage feature