1. Introduction
The low water crossing involves the construction of bridge when the water level is low. Once the water level increases it increases beyond the point and overflows in the bridge. This system is cheaper than the other formats. The low water crossing allows the vehicle to cross freely in the wet road. There are some constrains for getting permit to construct low water crossing. The term low water crossing means the surface is usually dry and the ford means the surface is usually wet. Culverts help in construction of cost effective water level crossing. The accurate low water bridge is an brilliant engineered structure, many similar structures are available in united states. The low water crossing engineering designed considers lot of factors like construction, vegetation in that land, maintaining water velocity etc. The waterway would be non navigable expect during flood conditions anyway. The low water level crossing is safe and cost effective for effective crossing. There is a certain limit in using the low water crossing once the water level increases it overflows through the bridge and become unsafe for the public. The force of the moving water may be strong enough to physically push the vehicle off the bridge, the higher percentage of the vehicle in the water. There are some rules and regulations to be followed while constructing the low water crossing projects.
2. Rules and Regulation of Environmental Protection Agency
Water way crossing should be selected from the following criteria.
- Long life time with the good efficiency in the water flow.
- Low water crossing should have stable and good soil conditions.
- The velocity of water flow should be very low even in the flood conditions.
- The space should be more, so that the public can easily enter.
2.1 Construction Permit
The construction of low water crossing is not an ordinary work, it should be permitted by the federal agency, Environmental Protection Agency before starting the work. The permits are required from all of the following: Alteration of the work, enlargement of any project plan, repairs and maintenance of bridges in any aspects, culverts. The construction activities include any clearing, grading, excavating. Usually the construction was done in one or more acre of land or less than one acre of land. This permit also authorizes storm water discharges from support activities
- Before starting the construction activity it requires NPDES permit coverage.
- The activity should not involve commercial operation it needs multiple constructions work.
- The Strict steps should be taken to control the water pollution.
- The support activity should be properly defined in NOI
2.2 Water Maintenance
The runway ditches should be disposed properly in order to avoid the pollution in road beds, and the water should be maintained with the stable velocity. The ditches should be made a separate path to outlet the ditches frequently. The runoff control is the important factor to prevent the polluted runoff in the road, highways and bridges from reaching surface water. The erosion before and after construction of road can make polluted runoff water. The runoff control shold be implemented in the highway and the bridge construction in order to reduce the runoff pollution in before and after construction, such measures can save the surface water from the pollution.
2.3 Vegetation Disturbance and Code of Federal Regulations on Low Water Crossing
In the agriculture region the biodiversity removal has be increased. The farmers cannot able to maintain the ecological function in the plant community. This entirely affects the Avon region only 13 percent of vegetation is done in this region. The vegetation can be reduced in the low water construction projects the re vegetation shall be continued in the other lands. The re vegetation can be done in the lands within the one year of time frame. The adequate amount of land is given for re vegetation. The code of federal regulation is responsible for the current engineering practices in the low water crossing region. The main motto of Code of federal regulation agency is to reduce the erosion before and after construction. The low water crossing other than bridges should have a improved construction in order the vehicles should have good passing. The bridges should be designed less than 10 years of frequent discharge.
3.0 Arizona Game and fish Department’s Fauna Protection
The Arizona Game and fish department is responsible for conserving and restoring Arizona’s wildlife resources and habitats by aggressive protection and management programs. The Arizona game and fish department has developed a plan on “Comprehensive wildlife conservation strategy” (CWCS). The CWCS manages Arizona’s fish, wildlife and natural habitats by combining with various agency cooperators etc. The Arizona’s game and fish department is responsible to recover endangered species to help and educating children about the environment.
3.1 Allowed Discharge and construction procedure over river
The Arizona state has Salt River (Gila River). The river is 200miles long and the drainage basin is about 13, 700 square feet. The Salt River reservoir has the storage capacity of 2,910,200 acre feet. The dangerous flash floods occurs especially during the month of July and august. The flood waters can be washed out at roads. The bridges have been damaged in 1980, 1993 and 2005. The natural flow of Salt River is 2,570 cubic feet per second, but after rainfall Salt River will become dry. This river is used for irrigation by the American settlers in the late 19th century.
The apache trout and Gila trout is officially designated as Arizona’s state fish and it was found in the head waters of white, black and Little Colorado River above 5, 900 feet in the east central Arizona. The apache trout have an olive yellow color. The apache trout have been restored to much of their historic range in the white mountain.
3.2 Endangered wildlife species
The Arizona’s wild life species are facing great threat day by day from the habitat degradation diseases. The most of the species faces threat due to the climatic changes. The Arizona and fish department made partnership with the public department like nonprofit organization started a recovery aim program. The program aims to prevent species from becoming endangered in a cost effective manner. The state level involvement provides closer oversight of the wild life species on a day to day basis. There are totally 37 animal species in the Arizona listed as threatened. The adaptive management of these species will ensure to continued presence in Arizona. There is some species recovery program listed below.
- The Mexican wolf management
- Bald Eagle Management
- Jaquar Conservation
- Turtle Management
- Arizona Birds Conservation management
- Bat conservation and management
The Arizona Game and fish department species recovery program implements a general guidelines and partnership program. There are some endangered species in the Arizona like Mexican wolf, bald eagle, jaguar, turtle, Arizona birds, and bat.
4.0 Conclusion
The low water crossing is one of the most useful systems in bringing water from one road side to the other road side. The construction of such system needs some kind of permit particularly from NPDES in order to ensure the safety for the public and the workers. The water is maintained properly and some other steps have been taken to ensure the water quality and species inside the water. The vegetation can be reduced in the low water crossing area and it can be re vegetated in the other woody lands. The Arizona game and fish department has certain regulation on the protection of fauna. They have formed the comprehensive conservation wildlife strategy to ensure the productivity of the wild life. There is certain discharging capacity of water at Arizona area to avoid flood during seasons.
References
1. Low Water Crossing, Wikipedia, 20 Apr 2009. Web. 31 Dec 2013. http://en.wikipedia.org/wiki/Low_water_crossing
2. Salt River, Wikipedia, 20 Dec 2013. Web. 31 Dec 2013. http://en.wikipedia.org/wiki/Salt_River_(Arizona)
3. Threaded and endangered species conservation, Arizona Game and Fish Department, 11 Jan 2013. Web. 31 Dec 2013. http://www.azgfd.gov/w_c/conservation/EndangeredWildlifeConservation.shtml
4. Arizona Game and Fish Department, Wikipedia, 27 Jul 2013.Web. 31 Dec 2013. http://en.wikipedia.org/wiki/Arizona_Game_and_Fish_Department
