Probably both factors were important to the formation and modification of the pools. At Vina, it appears that pool clusters developed from temporary meander pools. When some individual streams that were part of an alluvial fan became isolated, these pools formed with seasonal rains and their shape was modified with the help of kinetic energy from winds. Vina plains has pools in different stages of formation and pools that are found on elevated areas with isolated drainage basins. The larger pools on Vina Plains Preserve have a mixture of exposed hardpan and clay and even have arcs of cobbles that indicate sorting from past river activity.
Some pools have deep clay deposits that form distinctive islands or peninsulas.
The larger pools are exposed to high wind energy during the rainy season which produces large waves that physically move the sediments. The preserve has a gentle southern exposure, and the larger pools are extending north as wave activity cuts into the Tuscan Loam, exposing the hardpan. In contrast, clay soils of some depth form along the southern edges and in protected areas of the pools. The preserve contains almost 300 plant species. The pools and the clay soil drainage channels form an irregular temporary wetland supporting amphibious plants such as meadowfoam, goldfields, and downingia that germinate in saturated soil and form distinctive flower bands as the pools dry.