An Exterior Drainage Maintenance Calendar for La Jolla Homes

Drainage around a house is a set of parts: gutters, downspouts, extensions, splash blocks, area drains, outlet pipes, swales, sloped hardscape, and the irrigation system that adds water on purpose. Each one works only as long as somebody keeps it working. Leaves fill a gutter. A downspout extension gets kicked aside by the gardener. A drain grate ends up under a layer of mulch. A sprinkler head drifts until it’s spraying the wall.

Our foundation drainage page covers how we evaluate water paths and what corrections look like. This post is the upkeep side: what to check, and when, so the drainage you already have keeps doing its job. If you’re still figuring out where the water on your lot comes from, start with coastal moisture and foundation drainage patterns. If you’re choosing between systems, see French drains vs grading.

The short version: service everything in late summer and early fall, before the rains. Walk the lot during and after storms. Repair washouts and re-seal joints in spring. Through the dry months, keep irrigation steady, off the walls, and off the street.

Build the calendar around the rain

San Diego’s rain comes in one season. The National Weather Service’s Climate of San Diego memorandum describes rainfall as “generally a late Fall through early Spring phenomenon (occurring from the end of October through April),” and says “eighty-five percent of the rainfall occurs from November through March, but wide variations take place in monthly and seasonal totals.” A U.S. Geological Survey fact sheet on Southern California landslides describes a winter rainy season that “typically lasts from November through April.”

Those figures come from regional records, not your lot, and some winters are much wetter than others. But they give a clear rhythm. Get the drainage ready before November. Watch it work through April. Fix what the season broke in spring. Then manage irrigation through the dry months, when it becomes the main water reaching your soil.

Before you start: list your drainage parts

A calendar only helps if you know what you’re maintaining. Walk the house once and write down:

• Each downspout, and where its water ends up (splash block, extension, buried pipe, swale, curb outlet)
• Each area drain or catch basin grate in the yard, and where its pipe comes out, if you know
• Swales or shallow channels that carry water around the house
• Patios, walks, and driveways next to the house, and which way they tilt
• Retaining walls and their weep holes or drain outlets
• A sump pump, if you have one, and where it discharges
• Irrigation zones near the house: sprays, drip lines, and the controller

A rough sketch with numbers on each item makes the rest of this easier. If you’d rather trace the water during a storm, our post on hillside drainage before structural repair walks through that process from roof to street.

Late summer and early fall: get ready (August to October)

This is the window that matters most. Whatever you fix now gets tested within weeks.

Gutters. HUD’s Residential Rehabilitation Inspection Guide says to “make certain all gutters are clean and slope uniformly, without low areas, to downspouts.” If you have gutter screens, check their “condition, fit, and position, to be sure water really can enter the gutter.” Without screens, HUD expects “basket strainers are installed at each downspout.” Look for sagging sections and loose hangers too. HUD says “rusted fasteners and missing hangers should be replaced.”

Downspouts. HUD calls for straps “at the top, at the bottom, and at each intermediate joint,” checked for “rust, deformation, and failed or loose fasteners.” Make sure each downspout is clear and that it discharges “so water will drain away from the foundation.” On a house with more than one roof level, upper gutters should drain to lower gutters through downspouts, not onto the roofing below.

Where the water lands. Reattach any extension that’s been knocked loose, and replace cracked splash blocks. The California Residential Code has a specific rule for homes on problem soils: “In areas where expansive soils or collapsible soils are known to exist,” roof drainage must discharge “not less than 5 feet (1524 mm) from foundation walls or to an approved drainage system” (Section R801.3). If your lot has a geotechnical report that mentions either kind of soil, that’s the standard to check against. Our companion post on soil moisture cycles and settlement explains why those soils are sensitive to water.

Area drains and grates. Pull leaves, mulch, and soil off every grate. The California Geotechnical Engineering Association’s homeowner guide says to “make sure drain inlets are at, or just below, the ground surface level so water can flow into them.” A grate sitting higher than the soil around it can’t collect anything.

Testing drain lines. It’s tempting to flush pipes with a hose, but think about where that water goes. San Diego Municipal Code §43.0304 makes it unlawful to “cause a non-storm water discharge” to the storm drain system except as the code allows, and the system includes street gutters. Don’t wash debris or sediment out to the curb. The first light rain is a fine test: watch where each outlet runs. If a line doesn’t flow, have it cleared.

Grade and soil against the house. Look for soil or mulch piled up against the walls and for low spots where water could sit. The residential code baseline is ground falling “not fewer than 6 inches (152 mm) within the first 10 feet” away from foundation walls, with drains or swales where the lot can’t allow that. Our French drains vs grading post covers what to do when you can’t get that fall. Light raking is maintenance. Reshaping a yard isn’t: CalGeo advises against modifying “the ground level or surface drainage pattern at your property without consulting a knowledgeable construction or design professional.”

Cracks and joints in hardscape. CalGeo recommends keeping “concrete cracks and joints sealed to reduce water infiltration,” and repairing or sealing gaps in patio slabs or pool decks “promptly.” Fall is a good time, before water has a chance to get in.

Retaining walls. Clear weep holes and look at wall drain outlets. Our retaining wall monitoring checklist covers what to log, and the post on drainage behind retaining walls explains how those systems work.

Sump pump. If you have one, test it and check its discharge line. HUD’s guide reminds inspectors to check that a sump’s “discharge is not draining back” toward the house. Our post on sump concepts and moisture control covers where discharge is allowed to go.

The curb. The City’s storm preparedness page asks residents to place trash, yard, and recycling bins “approximately 2 to 3 feet away from the curb so they do not impede the flow of stormwater,” and to “sweep up trash, sediment, and debris” so it doesn’t block the storm drain system. Your downspout and curb outlets drain into that same system.

During the rainy season (November to April)

Walk the lot in a storm, safely. This is when you learn whether the fall work held. Look for gutters overflowing at one spot, downspouts that aren’t running when they should, water pooling against the house, and soil washing away at a downspout or drain outlet. Take photos. Don’t climb ladders or go onto slopes in the rain.

Turn the irrigation off. If the City is your water provider, its permanent water-use rules prohibit “the application of potable water to outdoor landscapes during and within 48 hours after measurable rainfall.” That’s also good practice for your soil. CalGeo’s guidance is to water “more in dry times and less in wetter seasons.” A controller with a rain sensor or a smart controller helps. The City’s stormwater program lists “automatic rain shutoff devices or smart controllers” as ways to reduce irrigation runoff, and CalGeo suggests “rain gauge monitored irrigation systems to prevent overwatering during the winter.”

After each big storm. Clear grates again, put extensions back, and look for new erosion. On sloped ground, the City’s minimum stormwater practices call for exposed soil that’s eroding to be “protected from erosion,” and for “significant accumulations of eroded soil” to be removed or contained so they don’t wash into the storm drain. A blocked street storm drain can be reported to the City through the Get It Done app. For flooding, the City’s emergency dispatch line is 619-527-7500. For anything life-threatening, call 911.

Check under the house. If you have a crawl space, look in after the first big storm. HUD’s guide makes the point well: if moisture is coming through foundation walls, “re-examine the roof drainage system and grading around the exterior of the building (the problem could be as simple as a clogged gutter).” Our post on wet crawl space warning signs covers what to look for.

Spring: repair what the season broke (April to May)

Once the rain tapers off, go back through your list:

• Fill and compact washouts at downspout outlets and along swales
• Reset splash blocks and extensions that moved
• Re-seal hardscape joints and cracks that opened over the winter
• Check gutter hangers and downspout straps again
• Note any low spots that held water, and decide whether they’re a raking job or a regrading job
• Compare your storm photos with last year’s. A spot that ponds every year is a pattern worth fixing properly.

If a problem kept coming back all winter despite clean gutters and clear drains, it’s probably not a maintenance issue anymore. That’s the point to get the drainage itself looked at.

The dry months: irrigation is your drainage (June to September)

Between rainy seasons, irrigation is the water source you control. That makes it the thing to manage.

Water steadily. CalGeo’s advice for homes on expansive soil is to “water your yard in moderation but also consistently,” and not to shut irrigation off for a long trip, “especially during dry weather.” CalGeo’s guide explains why: in expansive soil, ground movement “can occur when significant changes in moisture levels occur.”

Keep water off the house and off the street. CalGeo says to “keep sprinklers away from foundations” and recommends drip irrigation. The City’s water-use rules prohibit irrigation “in a manner that causes runoff” onto neighboring property, walkways, roadways, or structures, and allow landscape watering only “before 10 a.m. or after 6 p.m.” The municipal code goes further: “Illicit discharge includes irrigation runoff discharged to the MS4,” the storm drain system.

Adjust the controller. CalGeo recommends “timers that can be seasonally adjusted.” Reset run times as the weather warms in summer and again when it cools in fall.

Fix leaks fast. City rules require customers to “repair or stop all water leaks upon discovery or within 72 hours of notification” by the City. CalGeo’s list includes leaks in “irrigation systems, plumbing, pools and spas.” The City also says not to overfill pools and spas.

Look at the sprinkler pattern. The City’s stormwater program calls for “regular maintenance and visual observation” of irrigation “to prevent overspray, leaks, and other problems that result in runoff.” A simple habit: run each zone by itself now and then and watch where the water goes.

The calendar at a glance

When maintenance isn’t enough

Maintenance keeps good drainage working. It can’t fix drainage that was never right, and it doesn’t repair a foundation that’s already moved. Get an evaluation if:

• Water still collects against the house after gutters and drains are clear
• The same spot ponds every winter
• A crawl space gets wet after every storm
• Soil keeps washing out from under a slab edge or footing
• Cracks, sticking doors, or sloping floors show up near a wet area

A foundation inspection looks at the water and the structure together. If the house is already showing movement, our foundation settlement repair page explains how the cause gets sorted out. For crawl-space moisture tied to structural damage, see crawl space foundation repair.

Cost factors, not prices

We don’t publish prices. Routine maintenance is mostly your time. When drainage needs correction, what shapes the scope: how many problem spots there are, whether the fix is reattaching and extending versus regrading or adding subsurface drains, where water can legally discharge, lot slope and access, whether a retaining wall or crawl space is involved, whether a soils or engineering review is needed, and what permits apply.

Where we fit

We evaluate drainage and foundation concerns for homeowners across La Jolla and handle drainage corrections within our scope. When drainage design or soil conditions call for engineering, we coordinate with licensed engineers as needed. This post is general education, not a design for any specific property.

Next step

If water keeps finding your foundation despite regular upkeep, request a Free Quote for an on-site evaluation anywhere in La Jolla, or call (650) 739-6537.

Sources (accessed October 19, 2026)

• NOAA / National Weather Service, Technical Memorandum NWS WR-270, Climate of San Diego, California (revised 2004)
• U.S. Geological Survey, Fact Sheet 2005-3107, Southern California Landslides: An Overview
• U.S. Department of Housing and Urban Development, Residential Rehabilitation Inspection Guide (2000) (accessed October 18, 2026)
• 2025 California Residential Code, Sections R401.3 (Drainage) and R801.3 (Roof drainage)
• City of San Diego Public Utilities, Water Use Restrictions
• City of San Diego, Storm Preparedness
• San Diego Municipal Code Chapter 4, Article 3, Division 3, Sections 43.0302 and 43.0304
• City of San Diego Jurisdictional Runoff Management Plan, Appendix IX, Minimum BMPs for Residential, Industrial, Commercial, and Municipal Sites/Sources (BMPs 6 and 14)
• California Geotechnical Engineering Association (CalGeo), Coexisting with Expansive Soil: An Informational Guide for Homeowners (2013)