During the Swedish period (1609–1702), on the territory of Catherine Park, there was an estate of a Swedish magnate — the Sarskaya Manor (Finnish Saari mojs, Swedish Sarishoff — "elevated place"). It was a small estate consisting of a wooden house, utility outbuildings, and a modest garden divided by two perpendicular alleys into four squares. The Vangazi River, flowing at the bottom of the ravine, was dammed, creating a large pond above the dam. This settlement is first mentioned as part of the Nikolsky Izhora parish in the "Census and Taxation Book of Novgorod Votskaya Pyatina of 1501." On maps made for Boris Godunov, the estate is named "Saritsa." Later, under the influence of Russian folk etymology, the name transformed into "Sarskaya Manor," then into "Saarskoye Village," and finally became Tsarskoye Selo.

After the Swedes were expelled from this area, Peter I gifted the manor to A. D. Menshikov, and later, on June 13 (24), 1710, by the emperor's decree, the Sarskaya Manor (together with 43 attached villages and lands) was given to Marta Skavronskaya, who became his wife in 1712 under the name Catherine Alexeyevna. Between 1718 and 1724, according to the project of architect Johann Braunstein, a small two-story stone palace was built here, surrounded by utility buildings. On the western side of the palace was the Menagerie — a fenced-off section of forest where boars, moose, and hares were kept for the tsar’s hunting. The garden expanded, newly replanned with terraces by the landscape artist Jan Roosen in 1719–1722. According to his design, garden master Johan Focht laid out a straight perspective from the stone chambers to the menagerie, reinforced the banks of the Large Pond with piles, and gave it a hexagonal shape. A Fish Channel was dug, connecting the Large Pond with the canal along the settlement. Roosen used the natural slope of the hill and planned the garden in terraces. The higher part adjoining the palace from the east became known as the Upper Garden, and the lower, more distant part as the Lower Garden. Garden "delights" were arranged here: gazebos, trellises, bosquets; neatly trimmed trees were planted in straight rows along the alleys. Along the paths among the greenery, sculptures made by Italian masters of the Venetian school, acquired by Peter I, were displayed. In 1723, architect I. Ferster built a pleasure pavilion on a pile-reinforced island in the Large Pond. In the same year, construction of a large orangery began. The southern boundary of the park at that time was the Fish Channel. The part of the park beyond the channel was called the "wild grove," where various species of trees grew freely.

In the early decades of the 18th century, work began on laying canals and creating lakes, as there were no natural rivers or lakes in this area. Initial difficulties with water supply in Tsarskoye Selo were so great that during the imperial court’s stay here, water had to be brought in barrels from St. Petersburg. The Large Pond had no sources of water supply except rain and swamp waters. The water supply problem was solved only after the Wittolovsky Canal was dug in 1749 from the springs near the village of Bolshoye Wittolovo. The springs emerge at a location 9.5 meters higher than the level of the Large Pond. Flooding the Large Pond led to the creation of a system of ponds in Catherine Park. A dam was built on the stream flowing at the bottom of the ravine behind the Hermitage, followed by the construction of three more dams. Five ponds were dug along the ravine; three of them (Lower Cascade Ponds) bordered the garden from the southeast, and two (Small Cascade Ponds) bordered the service settlement. Then, already at the end of the 18th century, the Taitsky water conduit was laid from springs near the village of Taitsy, located sixteen kilometers southwest of the royal residence.

Source:

https://ru.wikipedia.org/wiki/Екатерининский_парк_(Царское_Село)#/