Boise River

Agriculture

The Ada and Canyon counties, which form the part of treasure valley in the Idaho state, support a large agricultural irrigation industry. They use around 65 percent of the water from the Boise River for their purposes (Ritter & Shirmohammadi, 2001). The Boise River is an important source of irrigation water and a tributary of the Snake River with a length of 102 miles and a basin area of 4,100 square meters. Its waters melt from the snows of the mountains; thus, the source of the river is relatively pure (Ritter & Shirmohammadi, 2001).

The Boise River runs through Boise, Idaho City, and Atlanta among others. The water is diverted from the river using a dense network of canals. The irrigation canals are operated by various players such as irrigation districts and canal companies. For the purpose of irrigation, the ground water from the river’s companion aquifer is also utilized. Ada County, a beneficiary of the Boise irrigation water, was the fifth largest water consumer in 2005 (Wang, 2011), while the canyon county was the twelfth in the same study.

The two counties account for ten percent water use in the Idaho State, which means that the latter used 19.5 gallons per day in 2005. The total irrigation withdraws for crops for the whole of Idaho state was 16512 (Mga/d) in the same year. Ada County accounted for around 71% of this total whereas Canyon County took the remaining 29% (Wang, 2011).

Boise River

The Boise River is an important source of income to Idaho State as many activities that are undertaken in it, such as agriculture, fishing, and forestry, that have contributed to the creation of work places. Therefore, the economic importance of this river is large in Idaho State: there are estimated 150,000 acres under irrigation and more than 60 types of crops produced. A great number of livestock production and food processing units also contributes to the State’s profit (Schary & Fisher-Vanden, 2004). It is important to mention that these activities are entirely depended on irrigated crops. Boise River is, therefore, an important river in Idaho, but pollution is endangering its existence. That is why urgent measures to save it should be devised.

Historical data

Boise River is an important natural resource used by the community, especially for providing partial drinking water for the city of Boise. In the lower part of Boise River, irrigation of agricultural cropland is the primary use of water, that is several industries take its waters for production purposes. In the 1980s and 1990s, Boise River had relative flows (Schary & Fisher-Vanden, 2014). As a result, irrigation has altered the river’s natural flow. Besides, the construction of canals laterals and diverted drains have impacts on it. Diversion of more than a half of the water of Boise River takes place before Boise town, and the drains return to the river in the lower areas such as Middleton. During the irrigation period, the in-stream flows are generally low at Middleton. Thus, the impacts of irrigation, mainly done through canals, have led to pollution of the Boise River. Studies have shown that concentrations of the Boise water increased as the water flowed downstream, hence, supporting the idea that indeed agriculture was contributing to pollution of the river.

Contamination

There exist two sets of pollutions to the Boise River: point pollutants and non-pollutants. The former are mainly wastes from industrial processes and urban households, which have been controlled through measures such as the construction of sewerage treatment plants. The rapidly growing population in urban areas has necessitated such act (Schary& Fisher-Vanden, 2004). Specifically, the number of citizens in the Canyon and Ada counties had a growth of 37% in 2005 and later grew steadily. The upstream pollution is mainly caused by urban activities while the lower stream pollution is caused by agricultural activities. Various measures put in place by different players have controlled the point pollutants.

The non-point pollutants are still a problem because they tend to increase downstream. The major pollutants include inorganic nitrogen, phosphorous, sediment levels, pesticides residues among others. Agricultural activities as well as animal wastes and corps that require high phosphorous applications contribute a significant level of phosphorous to the river (Bottum, 2008). High-value crops take enormous levels of phosphorous while low-value crops have less production of phosphorous. The high-value crops such as onions, potatoes among others require many fertilizers. On the other hand, grain and hay, which belong to low-value corps receive low fertilizer.

Problems with the Current Models

The major measures of pollution prevention in the lower Boise River include control of the point pollutants and reduction of the amount of pollutants from the industries. The nonpoint pollutants are a big concern that has over years been associated with agricultural activities (Segers, 2012). This does not mean that it is agriculture alone that contributes to nonpoint pollution. Previously, insufficient data to ascertain the causes of nonpoint pollutants was a major concern. Therefore, to achieve reduced full pollution, nonpoint controls should be increased. However, it is necessary to mention that developments have been made continuously in Canyon and Ada counties. Specifically, researchers have elaborated cost-effective practices to reduce sentiment flows (Segers, 2012). Maintaining a steady flow of water with constant volume throughout the river would have solved the problem, namely, this would tend to neutralize the effects of pollution. This is, however, difficult to do because of the canals that take in water for irrigation and other activities. For this particular purpose practices such as vegetative filter strips, sediment basins, and mini basins were commonly used. However, the measures have not achieved the required levels of pollution control. Moreover, in Ada County, where the implementation is voluntary, farm operators are not forced to implement the expensive measures (Bottum, 2008). In order to improve the situation, the government provides subsidized loans to operators for making these steps.