Gunnison - Paonia Feldman Diversion Reconstruction Project (Parts 1 & 2)_Water Activity Summary

Home Browse Search

The total decree for the Paonia Ditch is 34.54 cfs. The Paonia Ditch also carries water for the Wade and Hightower Ditches. The Paonia Ditch water serves 700 acres of agricultural lands. The bulk of this water irrigates fruit orchards, hay meadows and vineyards. The Town of Paonia holds 3.9 percent of the Paonia Ditch shares. This water is used to irrigate lawns and gardens within the town. Delta County owns several shares; this water is used to irrigate the ball fields at Volunteer Park, a County-owned recreation area near Paonia. The Feldman ditch decree is for 3.8 cfs and provides water for 76 acres of orchards and hay fields. Some gardens and yards are also irrigated from the Feldman ditch. In 2004, an unusually large volume of water entered the Feldman Ditch and washed it out, causing several thousand dollars in damage to the ditch and adding a huge volume of silt and debris to the river. Sediment and gravel losses from eroding bulldozed gravel dams are extremely high. This translates into higher sediment loads in the river and loss of adequate elevation required to meet the existing elevation of the ditch. The result is a vertical loss of riverbed and aquatic habitat upstream as the down-cutting process migrates. The two diversions are situated immediately upstream from a previous in-stream gravel mine. As a result of gravel mining, extensive downcutting and headcutting has occurred immediately below the current diversion points. This erosion of the river bed resulted in the need to move the diversion point of the Paonia Ditch upstream in past years. As result of these moves, the two diversions are nearly opposite one another on different sides of the river. The magnitude of the downcutting is evidenced by the fact that between 1992 and 1997 the river downcut 5 feet at the highway bridge located less than one-mile downstream of these diversions. Since mining in the river ceased in 1998 the downcutting has stopped. Headcutting upstream from the gravel pit has also been measured. At the point of diversion for the Paonia Ditch, approximately 3,000 feet upstream from the bridge, 30 inches of bank erosion and 24 inches of channel degradation was recorded in one year in 1997. The rock diversion structure for the Paonia Ditch may be slowing the advancement of further headcutting upstream but does exhibit signs of damage from the river headcutting below. In 1997, the North Fork River Improvement Association negotiated with the gravel company to quit mining in the channel and work only in the floodplain. The work in the floodplain has since been completed; it was reclaimed in March of 2004 and is now inactive. The gravel company has generously donated 19 acres in and along both sides of the river for a community river park. Further degradation of the riparian corridor, including the stream channel appears to be slowing since the cessation of in-stream mining. However, it is very possible that the existing diversion, which is acting as a grade control, could fail in a large runoff event. If this were to happen, the headcut could progress further upstream. Without rehabilitation, the river will likely remain braided with a very high width-to-depth ratio. Annual repairs to the diversion and the associated disturbance to the channel bed are expected to continue in the future if this project is not implemented. The uncontrolled and inefficient diversion of water at this site results in over-diverting flows which often leaves the downstream reach in a dewatered condition and downstream users without - 2 -