Project Need
Need For Project:
During the spring of 2011, high water volumes eroded stream banks and resulted in substantial property loss along sections of the Duchesne River. Shortly after the flooding receded, NRCS completed an Emergency Watershed Protection (EWP) project to address some of the property loss concerns voiced by landowners. This EWP project primarily involved bank armoring vast sections of the Duchesne River riparian area, focusing on an approximate 30-mile long reach of the river. While the bank armoring has been somewhat successful at protecting property and infrastructure, the armoring has had other unintended consequences. One major issue with bank armoring is that it does not address stream velocity or energy. Instead of a feature that dissipates energy, the armoring allows that stream energy to further build. This energy is transported either longitudinally or laterally within the stream, and often what results is that the energy erodes nearby unprotected streambanks. This exasperates a cycle of further bank armoring without actually addressing the root problem.
This proposed project involves a case where there are sections of rip rap installed by the NRCS located on a private lands parcel. Mr. Larry Defa in Hanna contacted the Utah DWR regarding his concern for bank erosion along the Duchesne River on property he owns. We made a site visit to his property and agreed with his concern. The river makes a sharp bend and could result in additional bank erosion during a high flow event. Portions of the rip rap have failed, a structure somewhat like an inappropriately constructed J-hook has failed, and now stream energy is actively eroding a bank that supports an irrigation intake. The stream section identified by this project lacks an appropriate thalweg channel-form where stream energy and water volume may be transported efficiently and in harmony with surrounding features. Not only is this channel form creating problems for the surrounding land owners by eroding banks and threatening an irrigation intake, but the channel habitat is undesirable for aquatic wildlife. This particular channel section is dominated by small, uniform cobble that provides limited fish and wildlife refugia, lacks depth and profile that would provide adequate cover, and has fast stream velocity across the entire proposed project area. There is no pool habitat. Additionally, Mr. Defa has a water withdrawal structure on this bend that could be catastrophically affected if further erosion occurs. The UDWR is always looking for possible stream habitat projects on the Duchesne River and are willing to be involved in the project. Property owners along the Duchesne River continue to apply for 404 permits to protect property adjoining the river. The UDWR has been able to provide recommendations to the permit applicants for structures that improve fish habitat while also stabilizing stream banks. However, since we have not been involved in the planning and implementation of these projects they usually result in the placement of RIPRAP without a fish habitat improvement component. RIPRAP addresses bank stabilization, but has minimal benefits for fish habitat enhancement. Funding this project ensures the UDWR will be involved in the planning and implementation of the project to address the fish habitat component while also stabilizing eroding stream banks. Additionally, we believe successful implementation of this project could stimulate interest in completing additional projects on the Duchesne River in the future. We as an agency desire to break the trend in the Duchesne River system that the answer to all stream bank erosion issues is to install bank armoring. This project would serve both as a template and example of a project that meets the needs of multiple user groups while providing substantial additional resource habitat value. As a result of stream bank erosion and other factors along the Duchesne River it is listed as an impaired stream for water quality.
Last, this project site is on the lowermost section of the Duchesne River CUP fishing easement and right-of-way. The Duchesne River is in the top 10 waters list of amount of angling hours received within the State of Utah. To say that this resource receives high angling pressure is an understatement. The upper Duchesne River is only a 1.5 hour drive from the Wasatch Front and receives substantial angling pressure from that clientele. The public has a perpetual right to fish at this location and thus has a substantial potential benefit to the angling public in this high use area if the fishery is improved. The top of the project area directly abuts one of the several public fishing easement access points and thus receives even higher than normal fishing pressure.
Objectives:
1. Stabilize stream bank
2. Stabilize and improve water withdrawal structure
3. Improve hydrologic features
4. Improve fish habitat
5. Build landowner relationships and reputable, balanced projects in this drainage
Project Location/Timing Justification (Why Here? Why Now?):
Threats are primarily directed at riverine habitat features:
We will address brush eradication risks via the nature of this project. If we do not implement this project, it is more than likely that the prescribed treatment on this riparian area will involve a massive bank armoring project. Bank armoring will involve removing all brush and natural vegetative features and replace with rock. This project will balance rock structure with natural vegetative structure by appropriately grading stream banks, installing additional bank vegetation, and the rock structures will protect the vegetative structure from the brunt of stream energy. Natural vegetative structure is then able to better protect the bank from erosion when the primary channel force is not eroding against it (i.e., this is the purpose of the floodplain). We will install one toe wood structure in this project. A toe wood structure directly utilizes natural vegetation as a large component of its function.
We address channelization and bank alteration with this project. Without this project, a future project will occur where banks are directly altered into a hardened armored feature providing little to no habitat value. If no project were to take place, the stream is already altering the banks with continual erosion. There is currently a vertical bank made of sediment that will continue to erode away. When we implement this project, we will install natural features that allow the floodplain to redevelop and serve its purpose. The banks will be allowed to revegetate. We will be working to re-develop the channel form, including thalweg and depth profile that will have a more natural ability to handle large flooding events while providing aquatic wildlife refugia.
There is currently a water diversion within the project area. We identified the presence of a diversion as a habitat threat within this project. The current structure is a simple diversion ditch with a small overflow return ditch back to the river. We do not have a problem with the structure's present operation. However, it is unlikely the present condition will be able to operate in perpetuity given the rate of degradation (erosion) around the canal entrance and adjacent streambank. If we were to not undertake the project, conventional wisdom would "fix" the structure with a fortified rock entrance, the return would be eliminated, and ultimately a push-up dam using on-site material would be implemented as the most cost-effective solution for the landowner to maintain water use and rights. Push-up dams require annual disturbance to maintain after spring runoff. It is possible that more water may be used as a result. Our solution is to place a crossvane in conjunction with the water withdrawal feature that will help permanently set the water level and direct water to go into the water diversion structure and affix the entrance to the canal so that it does not fail. Additionally, a properly designed crossvane passes sediment that is currently being captured within the canal entrance. Further, we will retain the water turnback feature adjacent to a j-hook feature so that the bank does not erode behind the turnback. Given that we are satisfied with the current operation of the water withdrawal structure, the threats and risks posed by the structure are limited to the habitat destruction that may occur if we do not implement a project that balances habitat value while providing necessary structure.
Our project will address sediment transport imbalance by protecting the streambank from further erosion while passing fine sediments. Crossvanes and j-hooks, by their innate design, allow habitat features and breaks to occur while passing fine sediments that inhibit interstitial spaces and deposit in pools. Additionally, the water withdrawal structure will be designed such to pass sediment rather than allowing sediment to aggrade in the structure.
Storms and flooding and stormwater runoff - without some type of project, further property damage is likely to occur, including property loss via lateral channel migration, and irrigation structure failure.
If the project is not completed, water quality will continue to be impaired with elevated loads of fine sediment. Fish and wildlife populations will not reach desirable and/or historic levels because habitat quality will continue to be reduced. Furthermore, if left untreated, streambank erosion has the possibility to continue to migrate downstream and increase sediment deposition into the Duchesne River. The use of traditional rock hardening that typically occurs in this area would provide no benefit to fisheries habitats and likely exacerbate the problem downstream. The risks associated with this project are the possibility of project failure during flood events, however similar projects in other portions of the region have held up during flood events. A sediment imbalance currently occurs in this section of the Duchesne River where more sediment is being put into the system than can be transported out, thereby degrading habitats for fish and other aquatic organisms. This is especially important for resident fish, including mountain whitefish and brown trout, but also fish occurring further downstream, including the Razorback Sucker, Colorado Pikeminnow, and the three species who use the Duchesne River for spawning activities. The riffle habitats they require are being filled in with sediment reducing both the quality and quantity of spawning habitat. Additionally for these species low velocity habitats are required for young of year survival and these habitats are particularly susceptible to increased sediment loads which will settle out into the low velocity habitats. Looking into the future with drought and climate change concerns we will likely continue to see diminished spring flushing flows and therefore need to reduce the overall sediment input to try and approach a sediment equilibrium in the system. If we can achieve this sediment equilibrium we will see an improvement to the habitats of the fish species listed above.
This project will benefit livestock by eliminating property loss caused by channel lateral migration where pastureland is being lost. Further, this project will also benefit livestock by securing the water withdrawal location of the Defa ranch. Note that livestock are not currently allowed to graze in the project area and are not a contributing factor to the issues we are experiencing as part of this project. No grazing changes are anticipated in the project area.
Relation To Management Plan:
This project would help to address "Threats" listed in the Utah Wildlife Action Plan: 1."Channelization / Bank Alteration (direct, intentional)" - the project would use structures and planting to increase the heterogeneity in stream channel characteristics and promote a more diverse riparian plant community (i.e., Potential Conservation Action Code 2.3.6). 2. "Sediment Transport Imbalance" - the project would use structures and planting to reduce the rate of streambank erosion, which can cause imbalance in sediment transport and elevated levels of nutrients (e.g., total phosphorous, TDS).
The Duchesne County Resource Management plan contains the following relevant policies: -- The management of the watershed should allow for continued multiple use. -- It should preserve the quality and quantity of water as well as environmental values and allow the watershed to support existing as well as future uses. -- Projects that will protect water quality during periods of flash flooding shall be encouraged and supported. -- It is the policy of Duchesne County to encourage private and public land owners/managers to maintain the important functions of riparian areas under their jurisdiction. -- Duchesne County supports the use of BMPs to avoid sedimentation impacts to riparian areas. --Support efforts to protect water quality and the quality of the associated fisheries. -- Support efforts to improve fish habitats while balancing the rights of adjacent landowners and holders of water rights. "Use bio-engineering methods that facilitate riparian vegetation growth for bank stabilization in lieu of hardened structures or surfaces."
Rangewide Conservation Agreement and Strategy for Roundtail Chub, Bluehead Sucker, and Flannelmouth Sucker - Enhance and maintain habitat for roundtail chub, bluehead sucker, and flannelmouth sucker. - See ecological threshold for further explanation on enhancing and maintaining habitat
Duchesne River TMDL -- Improve water quality in the watershed by decreasing the TDS and sediment load -- Improve wildlife habitat
State of Utah Resource Management Plan - The State supports the use of structural and non-structural improvements in unstable water courses to restore riparian areas properly functioning/desired future conditions. - Prioritize and manage riparian areas to attain desired future conditions for riparian related resources (e.g. fishery habitat, water quality, wildlife and livestock forage, and soil stability).
Razorback Sucker recovery plan - 5.2.1.1 Factor A.--Adequate habitat and range for recovered populations provided. - Spring peak flows are important to the dynamic
sediment processes that maintain in-channel habitat complexity, and prevent vegetation
encroachment and channel narrowing. For example, cobble and gravel deposits used for
spawning are relatively permanent features formed at high flows. Lower peak flows in
subsequent years result in deposition of fine sediments over cobble and gravel deposits. Peak
flows, whose timing coincides with the natural runoff cycle, are needed to ensure that suitable
sites, cleansed of fine sediments, are available during the spawning period. - See ecological thresholds for further explanation of sediment effects in the Duchesne River
Colorado Pikeminnow Recovery Plan - 5.2.1.Factor A.--Adequate habitat and range for recovered populations provided. - Spring peak flows are important to the dynamic
sediment processes that maintain in-channel habitat complexity, and prevent vegetation
encroachment and channel narrowing. For example, cobble and gravel deposits used for
spawning are relatively permanent features formed at high flows. Lower peak flows in
subsequent years result in deposition of fine sediments over cobble and gravel deposits. Peak
flows, whose timing coincides with the natural runoff cycle, are needed to ensure that suitable
sites, cleansed of fine sediments, are available during the spawning period. - See ecological thresholds for further explanation of sediment effects in the Duchesne River
Fire / Fuels:
N/A
Water Quality/Quantity:
The project will reduce erosion through natural form bank stabilization. Sediment that would be eroded from the project site will continue to be a problem in the Duchesne River with a no action alternative. Sediment is listed as a concern in the Duchesne River TMDL as identified by Utah DWQ. The project would stabilize the stream banks and re-establish a dense and diverse corridor of riparian vegetation. Additionally, the floodplain features created by natural channel design also reduce sediment inputs from streambank erosion by creating an important buffer zone and area of reduced velocity where sediments can deposit naturally. One of the primary functions of a floodplain is to capture sediment by naturally setting out in low velocity areas, thereby balancing sediment transport. Deep rooting vegetation that we will establish as part of this project allows for water infiltration during periods of high flow and rain events. The instream structures we will create as part of this project also allow proper, balanced sediment transport, which is critical toward maintaining interstitial spaces, clean gravels and cobbles that are critical to many life stages of aquatic organisms, including fish.
Compliance:
1. Archaeologist has been completed in vicinity, but will need to double check. Additionally, we will check into whether an archaeological clearance is required on private lands. DWR has an archaeologist on staff and will be consulted soon. 2. 404 permit (stream channel alteration permit) will be obtained via Utah Division of Water Rights and US ACOE. We anticipate a joint permit will cover these activities given the limited linear scope (350 linear ft of channel). 3. NEPA not required.
Methods:
Bankfull discharge will be calculated and a stream habitat design for the project will be based on bankfull discharge estimates. Current baseflow stream habitat metrics have already been collected. Heavy equipment will be used to install one toe wood structure on outside streambank to address erosion problems. These structures are installed by setting a foundation log nearly parallel to the streambank. Rootwads are placed on top of the foundation logs perpendicular to shore and anchored deeply into the stream bank. Cuttings from willows and trees are placed on top of the rootwads. The rootwads act as flow deflectors the deflect flow away from the bank. They also create cover for fish. Other structures including cross vanes (planning to install 3) and j-hooks (planning to install 2) will be placed in the stream above the eroding bank to deflect stream discharge to the center of the channel and to improve fish habitat. Generally these actions lead to deeper water habitats where water energy is directed and allowed to dissipate vertically rather than allowing continued lateral/horizonal water energy which causes stream bank erosion. Such efforts successfully scour deeper water habitats from channel aggradation and sedimentation, promoting sediment transport balance while providing substantial aquatic organism habitat value.
Monitoring:
After project completion, an inspection of structures and problematic bank built during the project will be inspected annually after the spring flood for 10 years. Fish population monitoring occurs on the Duchesne River every 5-7 yrs. The next scheduled fisheries survey will occur sometime after 2025. Fish population estimates are obtained by depletion removal electrofishing.
Partners:
Trout Unlimited will continue to assist with planning and execution of this project
Larry Defa (private landowner) - willing to contribute some machinery and trees/root wads to assist with this project
We will consult with the Uinta National Forest this spring (probably after snowmelt so that we can better see the boulder field we are interested in harvesting rock from) about the possibility to gain access to some raw materials (in this case, we need 3-5 ft diameter boulders for constructing crossvanes and j-hooks) and if they are able to provide these materials, they would be a substantial partner in this effort
Given that we are operating within the Utah Mitigation Commission fishing easement, we will be discussing the project with and cooperating with that agency
We will consult with UDWQ shortly to see if this project may qualify for nonpoint source funding which could reduce some of the current expense utilized from WRI sources
Future Management:
The area is not currently grazed, however we will have to ensure that case is followed explicitly while the re-vegetation phase takes place.
We will continue to monitor the project and ensure that additional vegetation plantings occur as necessary. The rock structures will be monitored regularly to ensure that additional tweaks are made as necessary (we don't expect much of this). Occasionally there may be a need to add or take away a rock or two out of a structure if it is causing an undesired or unrealized effect - often realized during a bankfull discharge event.
This project will definitely serve as a model for future work on the upper Duchesne River drainage for balancing wildlife and hydrology needs while achieving what is needed with landowner property loss concerns.
Sustainable Uses of Natural Resources:
The project would promote availability and sustainability of the Duchesne River sport fishery. The project site is immediately adjacent to a fisherman's access point. We are very aware that fisherman utilize it even in its heavily degraded state; with these improvements I would expect an exponential use increase associated with the project area because of the easy access and quality resident fish that are in this stream at nearby locations. Basically I would expect immediate colonization by quality fish. The work improves habitat for Brown Trout and Mountain Whitefish (e.g., reducing fine sediment that can limit spawning success, creating critical refuge for all life stages, etc.). The project would also protect nearby riparian pasture for livestock while improving and protecting an irrigation water withdrawal point.
Last, I consider it a sustainable use of natural resources when considering that this is the ideal location and project for a model to illustrate how we can achieve everything needed for agricultural uses on this property while promoting a healthy riparian habitat, balanced stream hydrology, and fishery. This project is appealing in its ability to please all stakeholders while maintaining a much higher aesthetic property value than bank armoring. Given that this project occurs on a well-known family in a tight-knit community, we are hopeful that our project's success will lead to further improvements in this area down the road.