In 1706, the États de Bourgogne had decided to appoint a chief Ingénieur des ponts et chaussées for the province. The first was a Mr. Jerson, who was replaced in November 1710 by a Mr. Morin, an architect. He held the post until 1736, when the States replaced him with a Mr. Bonnichon. When Bonnichon fell ill, Dumorey was appointed as his assistant. Dumorey became the Chief Engineer himself in 1750. In 1735, he drew up plans for the town hall at Chalon-sur-Saône, which was completed in 1742. In 1752, the States of Burgundy decided to create two assistant chief posts. Dumorey became the chief engineer of Ponts et Chaussées. In March 1752, "commissioning" was given over to Joseph Pierre Antoine, an alumnus of the École des Ponts et Chaussées, and to Charles Joseph Le Jolivet, a student. In 1758 a third assistant post was created and awarded to Émiland Marie Gauthey. He was the architect of the Château d'Arcelot from 1761 to 1764. In 1762 he worked on a plan for the provision of water to the publicwater fountains in Dijon, as a contractor for Dufour, the superintendent of Villeneuve-sous-Charigny. In 1768 he built a water fountain in Marjonzin, near the hamlet of Étroyes, where he owned land. This project perhaps replaced another, one to build a pump to supply the city of Chalon from the River Saône. That project was abandoned. Since 1751, ideas had been floated by the États de Bourgogne to study the improvement of the ports and quays along the River Saône. Dumorey submitted simplified plans in 1762, but not much happened. In 1770, superintendent Amelot asked the Mayor of Chalon, Claude Perrault, for a feasibility study with Gauthey and the town's tradesmen to ensure the project was workable. On 5 January 1771 the superindentant signed an order that Dumorey could continue the project "in the presence of interested parties" to give detailed estimates for the projected works. The decision was finalised in 1774, and in 1775, Dumorey took over responsibility for the project, with Gauthey. In 1777, Dumorey signed a contract for the Quai des Messageries. Work was completed in 1780 under Gauthey. Between 1772 and 1778, with Gauthey, he planned the enlargement and rebuilding of the electoral chamber oaround the cour de Flore of the Palace of the States of Dijon. At this time, Dumorey was the States' chief architect. In 1776, together with Gauthey, he designed the Fontaine aux Dauphins at Givry. He made studies for the Pont Joly at Semur-en-Auxois. The foundation stone was laid on 12 September 1779, and construction lasted until 1786. In 1780, Dumorey drew up plans for the barque bridge at Louhans. With Gauthey, Dumorey drew up plans for the Pont de Pierre over the Baulch stream on the road from Monéteau to Auxerre. This was built between 1781 and 1786.
