Three points up front
- Solana Beach’s own hazard annex says coastal erosion risk is highest where unstable cliffs become over-saturated by irrigation or rainwater.
- City code has addressed this for three decades: Ordinance 195 (1994) added section 17.62.160, which limits automatic irrigation within 100 feet of the bluff and requires bluff-top lots to drain away from the edge.
- Water is the bluff-top variable an owner controls most directly. It deserves the same attention as the foundation.
What happened in 1942
The City of Solana Beach annex to the county’s 2023 hazard mitigation plan recounts a nearby event, not one inside city limits. In 1942, it says, the Self-Realization Fellowship building fell into the ocean, and it attributes the collapse to erosion and slope failure caused by groundwater that had oversaturated the cliffs beneath it. That building stood a few miles up the coast in Encinitas.
The annex is careful to say Solana Beach itself has not had significant erosion events of that kind. It still uses the story for a reason. In its hazard summary, the same plan states plainly that coastal erosion risk is highest where geologically unstable cliffs become over-saturated by irrigation or rainwater. Elsewhere it lists “excessive rainfall or irrigation on a cliff or slope” among the ways slopes become unstable.
Rain is weather. Irrigation is a choice, and so is where a downspout empties.
Why water matters in these particular bluffs
Peer-reviewed work on this stretch of coast describes the seacliffs in two parts. In a 2006 Journal of Coastal Research paper, Young and Ashford describe a stronger lower unit and an upper unit of unlithified Pleistocene terrace deposits, and they note that both units are highly erodible. The paper’s first figure is a photograph of a seacliff failure in Solana Beach on September 28, 2004.
“Unlithified” is the key word for a homeowner. The upper material your patio, lawn and foundation sit on is not rock. Water moving through it, or running over the edge, works on it differently than the waves work on the lower cliff. A geotechnical engineer can tell you what’s under your own lot; general descriptions can’t.
What the City code actually says
Solana Beach adopted its shoreline protection chapter, SBMC 17.62, by ordinance in 1994. Its findings name the problem directly: erosion of the bluffs, the Council found, has also resulted from irrigation practices, storm water drainage, construction activity and climbing. Section 17.62.160 then turns that finding into rules for lots between the coastal bluff and the first public street.
Landscaping (17.62.160 A)
Landscaping on those lots must conform to City landscaping standards. The standards are meant to encourage native vegetation that thrives on seasonal rain and coastal moisture and needs minimal watering. Lawns and similar ground cover may be allowed, but subject to strict watering requirements, and the standards discourage work on the bluff face. The code also provides a path for keeping existing mature landscaping, using watering techniques approved by a licensed landscape architect and found by the city engineer not to create risk to bluff stability.
Irrigation (17.62.160 B)
Automatic irrigation systems are prohibited within 100 feet of the coastal bluff unless they include automatic shut-off valves and moisture sensors. The code describes retrofitting systems on the bluff, or within 25 feet of the bluff-top edge, with drip, mist and other very low-flow devices as reasonable steps an owner may take to minimize potential adverse impacts to the bluff.
Drainage (17.62.160 C)
Those lots must have drainage systems that carry surface water away from the bluff edge. Drainage over the edge or through the bluff is prohibited unless the water is contained in a pipe system approved by the city engineer. The code calls a system that conveys surface and subsurface water away from the bluff, to the street or an approved pipe system, a reasonable step to minimize bluff erosion.
One more provision in the same chapter is worth knowing. When the City evaluates a shoreline defense structure, one of the findings it considers is whether the owner or prior owners created the need for it by unreasonably failing to carry out generally accepted erosion and drainage control measures. Bluff-top water habits can show up in places owners don’t expect.
A walk-around for bluff-top owners
None of this requires a contractor to start. On a dry day, and again during or after a real rain, look at:
- The irrigation controller. Is it automatic? Does it have a moisture sensor and an automatic shut-off? Which zones reach within 100 feet of the edge?
- Heads near the edge. Spray heads within 25 feet of the bluff top are the first candidates for drip or removal.
- Lawn. How much turf sits on the ocean side of the house, and how often is it watered?
- Downspouts. Follow each one. Where does the water end up?
- Patio and hardscape. Which way do the slabs pitch? Toward the street or toward the edge?
- Pool and spa. Where does overflow or backwash go? Any unexplained water loss?
- Wet spots. Soft ground, persistent green, or seepage on the bluff face below your lot.
- Old pipes. Any abandoned drain lines that still discharge toward the bluff.
Write it down with photos and dates. If the house has a history of cracking, the record helps whoever evaluates it later.
Where the foundation comes in
Our work starts at the house, not on the bluff face. When we look at a bluff-top foundation in Solana Beach, water is one of the first questions: where it lands, where it soaks in, and whether any of it is heading toward the edge. Corrections can be modest, like rerouting downspouts and changing irrigation, or larger, like a collected drain system piped to the street. Where the design involves the bluff, a slope, or a code-approved drainage route, we coordinate with licensed engineers as needed, and a geotechnical engineer sets the site-specific recommendations.
Our bluff-top foundation repair, foundation drainage and upper-bluff repair pages cover that work in more detail.
Permits, honestly
The City’s Building Services page says the entire city is within the Coastal Zone, and that coastal development permits, waivers and exemptions are reviewed by the California Coastal Commission, not the City. For a bluff property, the City won’t approve the initial planning review until the Commission’s approval letter is in. Drainage changes near the bluff may also need the city engineer’s sign-off under 17.62.160. We don’t predict what any agency will decide or how long it will take. We help owners assemble a clear scope so those conversations start well.
What sets the scope of a water correction
The scope of a bluff-top water correction depends on lot size and slope, the number of downspouts and drain inlets, distance to the street or an approved outlet, existing irrigation, hardscape that has to come up, access on a tight coastal lot, geotechnical input, and whether permits or agency review apply.
The lesson, restated
The bluff will do what bluffs do. What an owner controls is how much water from the lot reaches it. Solana Beach wrote that into its code three decades ago. Our earlier post on pre-1977 Casa Mira bluff-top homes covers another part of the bluff-top picture, and our briefing on SB 326 balcony inspections covers the condo side.
If you own on the bluff and want a second set of eyes on drainage and the foundation, request a Free Quote.