The Hinman ditch has provided irrigation water for Niwot residents since 1865, when Porter M. Hinman, believed to be the first Left Hand Valley settler, dug his enlargement to the original Hornbaker ditch of 1861, (along with Sulvanus Budd and Jerome Gould).  Ten years later, in 1875, Hinman platted the town of Niwot.  “I would surmise,” local historian Ann Dyni commented, “that he thought that the parcel of land was especially choice because it was irrigated.”

The Hinman ditch is piped under SH 19 and then surfaces in an open ditch near Peppertree Estates, on the south side of Niwot Road.  It continues along the south side of Niwot Road, past Cottonwood Square Shopping Center and Cottonwood Condominiums, then turns north, in a pipe under Niwot Road, surfacing again just east of East Meadowdale and heads north.

Rumor has it that in the early part of the 20th century, ditch laterals, fed from the Hinman ditch, traversed many parts of Niwot. Residents used the laterals to fill their cisterns and to water domestic vegetable gardens.    Howard Morton, a longtime resident, remembers when the “filling station on the corner of Second (Avenue) and Niwot (Road) was lower than the roads.  A real big rain, a cloud-burst, would flood the ditch and it would overflow filling the station with mud.”

As part of the present repaving and sidewalk installations in Historic Downtown Niwot, the Boulder County Transportation Department decided to reroute the Hinman Ditch.  It will no longer run through Niwot, but will turn north on the westside of SH 19 and then head northeast, north of the Niwot Service Area.  The open ditch on the south side of Niwot Road will be filled and graded as part of this work.  
I would like 

to thank Tom Theobald, Ann Dyni, Don Spangler and Howard Morton, for their invaluable assistance in preparing this article.

Photo courtesy of the Doyle Hornbaker Collection, Niwot Historical Society.

Porter M. Hinman, believed to be the first Left Hand Valley settler. He filed the plat for the town of Niwot in 1875.  His family left Niwot before 1900.