In Çatalköy upper lanes, not every plot is fully landscaped. Between completed villas, there are unfinished or partially graded parcels where soil remains exposed. During dry periods, these surfaces appear harmless. During sudden rainfall, they change the behavior of the road below.

The exposure here is not general wetness.
It is concentrated runoff from raw soil edges crossing active slope lanes.

Upper Çatalköy sits on a stepped hillside. Many plots are terraced but not permanently stabilized. When rain begins, water does not simply fall onto asphalt. It gathers across exposed soil surfaces and accelerates downward under gravity.

Because unfinished edges often lack structured drainage channels, runoff exits directly onto the lane.

The risk concentrates in the first 15 to 25 minutes of rainfall, particularly after extended dry spells.

A typical sequence unfolds late afternoon.

At 17.10, a short Mediterranean shower begins after a dry week. Within minutes, water accumulates along an unfinished upper plot. The soil, compacted but untreated, releases a mix of fine sediment and water. This mixture flows diagonally across the descending lane beneath.

The stream is not deep. It is narrow and shallow.

Yet it crosses exactly at the entry point of a downhill bend.

A descending vehicle approaches at moderate speed. The driver anticipates wet asphalt but not lateral runoff carrying suspended sediment. As the front tires cross the stream mid-turn, traction reduces briefly.

Steering correction increases slightly to maintain line.

If an uphill vehicle approaches simultaneously, lateral margin tightens quickly.

Another layer involves sediment texture.

Unlike pure rainwater, runoff from unfinished soil contains fine clay particles. These particles create a thin, slippery layer over asphalt before being dispersed by continued rain.

The first vehicles through the stream experience the lowest friction.

After sustained rainfall, the sediment begins to wash away. But during the early minutes, surface condition is unpredictable.

Weekend weather shifts intensify exposure.

When rain coincides with late afternoon villa return traffic, descending vehicles from upper terraces encounter runoff at the same time as uphill drivers attempt to climb connectors toward home.

Evening light further complicates visibility.

As clouds thicken and natural light reduces, the water-sediment stream becomes harder to distinguish from surrounding wet asphalt. Headlight reflection may mask the difference entirely.

A specific 17.25 scenario illustrates compression.

A descending car rounds a right-hand bend just as runoff from an unfinished plot crosses the apex. The driver applies light braking before entering the curve. As the tires hit the sedimented stream, braking and steering overlap. The vehicle widens slightly.

An uphill vehicle enters the same bend from below. Both drivers reduce speed further, navigating with minimal lateral buffer.

No collision occurs. Yet the grip difference is felt immediately.

Çatalköy upper lanes include several developing parcels where landscaping is incomplete. Each represents a potential runoff source during sudden rain.

Unlike engineered drainage channels that direct water longitudinally, raw plot edges release water laterally.

The exposure is subtle but repeated.

It does not require heavy storm. Even moderate rainfall over dry soil can produce enough sediment-laced runoff to alter traction briefly.

In hillside residential environments, surface stability depends not only on road construction but on adjacent land condition.

In upper Çatalköy, unfinished plot edges become temporary tributaries during rain, redirecting soil and water across active descent paths.