Around 1790, a small river flowed past the old Kolcene manor house, which was built on a hill, through a low and wet meadow from the large Lauga swamp, which filled the Dzirnavu pond to power the mill.
One day, the countess, walking along the manor paths, thought that the landscape could be supplemented with a larger lake, as was the case at many manors. She turned to Count Mellin with her idea, who recognized this idea as a good one.
The count called together his people and invited them to help dig the pond, promising good pay for the work. The farmers willingly undertook the hard work. Farmers from neighboring manors also came here for profit. The pond was created for five years at that time, digging with shovels. The earth was poured into baskets and horse-drawn carts to be carried to the hills around the lake. An island was built on the opposite shore of the lake. To accumulate water and regulate its level, locks were built.
Since the pond was large in size, it has been called Bīriņi Lake since that time.
Also, during the construction of the New Castle building, the lake was expanded and its shore on the castle side was transformed. Locals remember their grandfathers’ stories about a row of horse-drawn carts, at the end of which the empty carts would stand, while the carts full of earth would leave from the other end to unload their cargo and return to the beginning of the row.