Runoff, Storm Drains and Bluff Faces in Solana Beach: A Briefing

Summary for owners and boards

• Solana Beach’s storm drains carry water to creeks, lagoons and the ocean without treatment, so the City restricts what may enter them.
• On bluff properties, the Land Use Plan points runoff toward the street and away from the bluff face.
• Irrigation overspray and washdown water are treated as non-storm water and are restricted.
• The structural concern is concentrated water at the bluff edge and around foundations.
• Most of the fix is mapping, maintenance and testing, with design work where pumps or new pipes are needed.

Private pipes, public drains

When rain hits a Solana Beach roof, it enters two systems at once. One is private: gutters, downspouts, area drains, pipes and sumps on the lot. The other is public: the curb, gutter, catch basins and storm drains in the street.

The San Diego Regional Water Quality Control Board describes the public side as a municipal separate storm sewer system, or MS4. It includes streets with drainage, catch basins, curbs, gutters, ditches, channels and storm drains, and it typically discharges directly to streams, bays or the ocean. The City’s own storm water program page makes the same point in plain words: storm drains are not connected to wastewater treatment, so water that enters them flows to creeks, lagoons and oceans untreated.

That shapes the rules for what may go in, and for where water from a bluff-top lot is supposed to go.

What the City’s code allows into the drains

Solana Beach’s storm water ordinance is SBMC Chapter 13.10. It states that its purposes include protecting water quality and keeping the City compliant with the Regional Board’s MS4 permit order. Unless exempted, it prohibits non-storm water discharges to the storm drain system. The list includes wash water from hosing impervious surfaces such as driveways and patios, pool or fountain water containing chlorine or other chemicals, and sediment and landscape waste. It also prohibits illegal connections, even ones built under a valid permit that were legal when constructed.

The City’s program page lists typical non-storm water discharges, including irrigation runoff from overspray and over-irrigation, and water from washing streets, sidewalks and parking lots.

For an association, those lists matter in two ways. Landscape and cleaning contracts should reflect them. And when a drain is redesigned, where it ties in is a compliance question as well as an engineering one.

Where the Land Use Plan sends bluff-top water

The City’s Local Coastal Program Land Use Plan, Chapter 4, treats water at the bluff edge as a hazard issue. In describing the shoreline, it lists storm water drainage and irrigation among the causes of surficial erosion on the bluffs, alongside wind, rain, construction and other factors.

Three policies follow from that:

1. Policy 4.7. New development must provide drainage and erosion control facilities that carry site drainage in a non-erosive manner.
2. Policy 4.26. For bluff properties, the City will require removal or capping of permanent irrigation within 100 feet of the bluff edge when it issues discretionary permits for new development, redevelopment, shoreline protection or bluff erosion work. The exception is where the owner shows the irrigation has no material impact on bluff erosion. The policy’s own example is watering hanging plants over hardscape that drains to the street.
3. Policy 4.28. Storm drain systems that drain, or used to drain, west over the bluff are to be capped and redesigned to drain directly, or through a sump and pump, to the street. The policy ties this to discretionary permits for bluff properties or a deadline after LCP adoption, whichever comes first.

Our earlier drainage briefing and the post on bluff-top irrigation cover the history and the irrigation rules. Here the focus is the pipe: what happens to water once it’s collected.

Why the structure cares

Water at the bluff edge does structural harm in a few ways:

• Gullies and surface loss. A pipe or overflow that empties onto the bluff face concentrates flow on a small area.
• Wet soil near foundations. Area drains that back up or sumps that fail can saturate soil next to footings and slabs on a lot that’s already close to the edge.
• Load on retention work. Upper-bluff structures and the ground around them perform best when water is managed above them. The upper-bluff repair page explains where these pieces meet.
• Hidden leaks. A cracked pipe under a patio can run for months before anyone sees a symptom.

None of this means a given property has a problem. It explains why drainage gets checked first in a bluff-top evaluation.

The sump question

On many bluff lots, the street sits uphill of the yard. Water can’t flow there by gravity, so Policy 4.28 allows a sump with a pump. That works only as long as the system is maintained. Practical items a board should track:

1. Where each sump is, what drains to it, and where its discharge line goes.
2. Whether it has a high-water alarm and backup power.
3. When the pump was last tested under load.
4. Who maintains it: the association or an individual owner.

The County’s private drainage flyer advises owners to inspect and clean private drainage systems before each rainy season and after storm events. That’s a good rhythm for sumps too.

What a board can do this season

1. Map the system. One drawing that shows roof drains, area drains, pipes, sumps, cleanouts and every discharge point.
2. Look for old west-facing outlets. Any pipe that once pointed at the bluff should be documented and its current status confirmed.
3. Review irrigation near the edge. Compare what runs within 100 feet of the bluff edge with Policy 4.26.
4. Update vendor scopes. Landscape and cleaning contracts should keep wash water and overspray out of the street drains.
5. Walk it after the first storm. Our post-storm checklist gives a sequence.

When distress shows up near the water

When a walk turns up wet soil near footings, cracked flatwork, or a sump that runs constantly, the next step is a structural look at the buildings near the water. Foundation drainage work on a bluff lot should be planned with the people responsible for the bluff, and a contractor should coordinate with licensed engineers as needed. On bluff-top foundation repair, the drainage design and the foundation design usually travel together.

We don’t predict what the City or the Coastal Commission will require on a given property. That depends on the project and the review.

Variables that size drainage-related work

1. Distance from the street, and whether gravity drainage is possible
2. Number and condition of existing drains, pipes and sumps
3. Any legacy outlets toward the bluff
4. Soil and foundation conditions near the water problem
5. Access around occupied buildings
6. Permit review for work on bluff properties

Need a structural read of drainage-related distress on a Solana Beach bluff-top property? Ask for a Free Quote.