The Relief Ditch has been diverting irrigation water from the main stem of the Gunnison River since 1890 and is listed as the number 5 senior priority in the Gunnison River watershed. In the early 1900’s the farmers who irrigated their crops from this ditch drove sections of railroad rails vertically into the river bed and used this with large rocks, trees and other materials to build a dam across the river to meet their irrigation needs. Over the years materials used in the dam would wash out and eventually the dam was replaced with an annual gravel push-up dam. The vertical railroad rails remained throughout the diversion’s history.
In 2004 Crane Associates was contracted by the Bureau of Reclamation to develop a feasibility study to reconstruct the diversion in a manner that would deliver a full decree of irrigation water while improving boating safety and fish migration in the newly designated Gunnison Gorge National Conservation Area. The study concluded that a low-head boulder diversion structure and a new headgate at the point of diversion would meet the goals of the project but convincing the Relief Ditch Board of Directors was more of a challenge. The livelihoods of these farmers are dependent on the delivery of water and changing something that is currently working was understandably an uphill battle.
In the meantime the popularity of boating and fishing through this magnificent flat-water stretch of the Gunnison River was growing. Canoe enthusiasts, tubers and fishermen struggled with a very narrow drop at the north end of the dam. Several rubber boats were damaged on the vertical railroad rails and the probability of a serious injury or drowning was on the rise. The Relief Ditch Board recognized this and was concerned for the safety of the general public. Jeff Crane approached the local chapter of Trout Unlimited in 2009 and worked with the Gunnison Gorge Anglers to sponsor and fundraise for the reconstruction project.
Crane Associates performed a field survey, a hydrologic computer model of the river and generated draft construction plans in 2010 to demonstrate to the Board that a reconstruction was not only feasible but in their best interest. A boulder low-head reconstructed diversion structure could withstand the high flashy flows of spring runoff, divert all the water they need during late summer low flows and reduce maintenance while eliminating a safety concern and an impediment to fish migration in this gold-water trout river. The Board approved the plans and Trout Unlimited raised over $800,000 to build the project.
The project broke ground in November 2012 and is currently under construction. It is due to be complete by the end of March 2013 prior to the next irrigation season. The design features a new concrete headgate with a slide gate at the point of diversion in the river. The gate will be equipped with a radio-controlled automatic control system that will allow the ditch company to regulate the flow in their ditch and measure the quantity of water in real-time. The low-head diversion structure will be completely submerged during most flow events and is paired up with symmetrical boulder structure 100’ downstream to act as grade control for long-term sustainability for the primary structure. The floodplain on both the north and south side of the river will be reconstructed to mirror the physical morphological characteristics of the river both up and downstream of the diversion. Fish habitat features will be included and a new floodplain will compliment the enhanced river channel.
Relief Ditch 2005 Prior to Construction