Gerhard, Ivan Kondratyevich ( Johann - Konrad) (1720–1808), an engineer, privy councillor. He was born in Germany (Schwabia) and he got the elementary education there after that he learned at the Academy of Sciences in St Petersburg. In 1765 he began to serve under the heading of Count Y.E. Sivers, the Novgorod governor, and Gerhard deserved the confidence of Count Sivers by his knowledge and diligence. From 1770 Gerhard took the post of an architect at the Imperial Water Constructions. The stores complex of the New Holland district (1765-1788), the Old Kalinkin Bridge across the Fontanka River (1786-1787), a bridge across the Kryukov Canal and the granite embankments of the Kryukov Canal (1801-1807), a pier with the descent on the Spit of Vasilyevsky Island and other constructions were built with participation of Gerhard. The construction of the 13-span constant drawbridge acroos the Neva River was designed by Gerhard (it was not realized ). Gerhard as a hydraulic engineering specialist worked on the development of the Ladoga Canal and the Vyshniy Volochek water way and also under the heading of F. Bauer he worked on the constructing of the Taitsi water supply system (1773-1784) for the providing Tsarskoye Selo by water. In 1795, when some parts of the water supply system became defunct, Gerhard suggested to replace the rotted wooden water pipes by the brickwork or to build the open stone canal with the fixing of the bottom and walls of the canal. The first more expencive variant was accepted. During 1795 - 1799 the stone canal with the length of 3 versts ( about 3 kilometres) was built by Engineer- Captain F. Toll under the heading of Gerhard . As well as the participation in the hydraulic work in St Petersburg , Gerhard as a member of the "Commission for the Water Constructions for Moscow" took part in the constructing of the Mytishchi water supply system. Gerhard headed the constructing after the death of Bauer, the author and the formal head of the constructing, in 1783. In 1797 Gerhard received the approval of his design for the providing Moscow by water and money for this work, all works were finished in 1804.

The sign of the cascade is two round narrowed upwards Gothic towers with red brick facades. Lancet windows, narrow slit-embrasures, merlon parapets give to the cascade the appearance of the fortress construction. It is explaned the second name of the construction in the memory of victories in the Russo-Turkish War. Cascade was built in the 1770s to the design of the architect I.G. Gerard. The cascade included three small dams which did not make possible water to flow down the relief slope too quickly. Upstream of a channel from the Upper Ponds to the Swam Ponds, on the Ramp Alley, the Pudost Bridge or “merlon dam” was built, the “Moss-grown rock” or “Wild hill weir-bridge” was constructed above it using tofus and limestones. The landscape architectural decorative design and “silver rapids” of crystal-clear Taitsi water flown down steps of the dam did the Red Cascade one of the most impressive park constructions. Gerard Ivan (Johann Konrad) Kondratievich

The Taitsi water supply system (TW) was the water supply system of Tsarskoye Selo built according to the order of Catherine II in 1772-1787 in exchange for the outweared Vittelevo water supply system. The military engineer F.V. Bauer was the main architect of the original design and so the water supply system was often named “Bauersky water supply system”. I.K. Gerard, E. Karboniyer (Karbonye) and P. Pozdeyev were also among engineers who took part in building the water supply system. The Taitsi water supply system was a gravity system of outside and underground channels with storage ponds and grottoes. This system was supplied with water from so called Hanniball or Soninsky springs located near the grange of Taitsi which belonged to A.G. Demidov since the 1770s. The Taitsi water channels extension was about fifteen kilometers. Walls and bottom of the water system was original wooden. In 1793 it was found out that the wooden casing of channels rotted through so in 1795-1799 it was reconstructed and the wooden casing was changed to stone facing. The reconstruction work was headed by I.K. Gerard. The Taitsi water supply system delivered more than 12.500 cubic metres of water per day to Tsarskoye Selo in summer time but in winter the supplying often decreased in 3-4 times. Firstly the Taitsi water supply system was intended for supplying the Tsarskoye Selo ponds and fountains but really it supplied with the water all population of Tsarskoye Selo, the town of Sophia, Pavlovsk. In the 1880s the Taitsi water supply system was used for creating the system of centralized water supplying system of Tsarskoye Selo (works were completed in 1887). Since 1905 when the Orlov pressure water supply system, which was supplied from the Orlovsky springs, was put into operation, the using of the Taitsi water supply system, for the supplying of the population by fresh water, was stopped. By that time the engineering state of the water supply system has already been inadequate and in the next tens years it fell out as a result of clogging up, destroying and being overgrown of channels. Single fragments of the water supply system can be seen at the present time. In the 1980s a group of enthusiasts made an unsuccessful attempt of restoring the Taitsi water supply system as a monument of engineering idea of the 18th century.
Literature: V.D. Dmitriyev “The Taitsi Water Supply System”, http://www.stroy-press.ru/print.php?id=7180
N.I. Falkovsky “The History of Water Supplying in Russia”, M., L., 1947, pages 115-118;
M.I. Pylyayev “The Forgotten Past of Saint Petersburg Environments”, SPb., 2006, p.
463
I.A. Krasnov, D.N. Starostin, A.S. Sukhorukova, Ye.D. Yukhneva “Water and the World: Essays on the history of water using.” Part 2: Water in Russia,. SPb., 2007, p-s 46-47
I. A. Krasnov Bauer Fedor Villimovich
Carbonnier (Carbonie), E.
Catherine II, Empress
Demidov Alexander Grigorievich
Gerard Ivan (Johann Konrad) Kondratievich
Pozdeyev, P.
Pavlovsk, town
Pushkin, town
София

The system of the Great Cascade ponds with dams was constructed to the design by Colonel-Engineer I. Gerard. Gerard Ivan (Johann Konrad) Kondratievich