Story by Nancy Ranney. Originally published in the SWGLA Newsletter.
One of the weakest links in the management of our ranch lands is the layout and construction of ranch roads. Historic wagon roads situated in the valley bottoms became ranch roads often traversed by heavy and damaging equipment. During a rainstorm, the road quickly becomes a conduit for all runoff that is intercepted from the uphill side of the road (and often from both sides of the road, if it is located at the exact middle of the valley). The road gathers and channelizes the runoff from the pasture, speeds up the flow as the water moves along and ultimately dumps it in the first arroyo it crosses; the arroyo channels into larger drainages and finally off the ranch entirely, in the process dewatering our pastures of vast quantities of precious moisture and disrupting natural drainage patterns.
In June-July of 2013, we contracted with Steve Carson of Rangeland Hands to redesign our ranch roads with the goal of capturing this runoff and throwing it back onto our pastures, in effect “harvesting” the water our ranch land received and keeping it on our land to irrigate our pastures. Steve calls this work “rehydrating the watershed” and believes it is the cornerstone of watershed restoration. The immediate effect is to increase plant vigor and diversity, increase water retention in adjacent rangeland and decrease erosion and sediment loss.
Steve visited our ranch initially to “read the landscape”, determine the extent of erosion and damage caused by the runoff from roads and then propose the design and installation of new “aggressive” drainage features to properly and regularly drain the roads and stitch the natural surface hydrological flow patterns back together. Happily, we had already been practicing planned rotational grazing on our ranch for ten years and had seen remarkable increases in soil fertility and variety of native grasses. Steve remarked that this practice was the first and most important step in retaining water on our grasslands.
The heart of his proposal was to install “rolling dip cross drains” at regular intervals along our roads as the topography dictated. These structures are wider and higher than the typical “water bar” or “thank you madam”, are well compacted and are installed at a 45 degree angle to the road with a long bladed runout into the pasture, often several hundred feet long. If done correctly, they need very little or no future maintenance and redistribute water back onto the pasture before it has a chance to concentrate on the road.
Steve moved a small camper onto our ranch and over the course of a month, installed approximately 109 rolling dip cross drains on fourteen miles of road on the North side of our ranch. Funds from an NRCS Conservation Stewardship Program (CSP) grant were used to pay for this work. He also re-aligned and reworked two access roads up very steep mesas that were in virtually unusable condition and which are vital to our ranch operation. I can now handle them easily in a Ford Expedition. He also created a couple of “brush grade controls” where roads crossed the creeks and recommended that we close a number of unnecessary roads to reduce our runoff and erosion problems.
Steve estimated that with an annual rainfall of 12” and 30,000 gallons of water per mile per inch of rain over 14 miles of road, we will conservatively be “harvesting”, or returning to our rangelands, 10,000,000 gallons of water/year (approx 30 acre feet).
This is a one time grading/draining of the roads. We are thrilled with the results we have seen in just over a year: much less runoff and erosion, increased plant vigor in our pastures and greatly increased water holding capacity of our soils. We hope to complete this work on the south side of our ranch in the very near future.