User:RightCowLeftCoast/Sandbox/Smuggler's Gulch

Smuggler's Gulch (Spanish: Cañon del Matadero or Valle Montezuma ) is a steep walled canyon, that is 14 mi inland of the Pacific Ocean. Smuggling activities within the gulch has occurred since the 19th Century, which gave the canyon its name. The gulch is vegetated with coastal sage scrub, and is home to threatened and special concern bird species. It has a seasonal stream, and normal flow is diverted for treatment. During the late 19th and early 20th centuries, agriculture occurred in the gulch, but was largely abandoned by the late 20th century. In the late 20th century, the gulch was used by illegal immigrants when crossing from Mexico into the United States, being described as a "prime route" during that period. It is on the Mexico-United States border, and since 2009 has been partially filled and transverse by the Mexico-United States barrier. Sewage flows through the gulch into the Tijuana River when it rains.

Flora and fauna
The flora of the gulch consist of coastal sage scrub. In the early 20th Century, golden-spined cereus (bergerocactus emoryi ) existed within the gulch, it is listed by the California Native Plant Society as a rare plant. In 2015, a small number of singlewhorl burrobrush (ambrosia monogyra) were documented near the mouth of the gulch, it too is listed as a rare plant by the California Native Plant Society.

Near and in the gulch, a few threatened and special concern species have been observed. These include the coastal california gnatcatcher (polioptila californica californica), and the northern harrier (circus cyaneus).

Geography
The gulch is a steep walled canyon, 14 mi inland of the Pacific Ocean. In the mid-19th century, Smuggler's Gulch had marshland and ponds of water. A stream which originates from the gulch had drained into the Tijuana River; the watershed of the gulch, a sub-watershed of the larger Tijuana River watershed, is about 6.7 sqmi and is mostly in Mexico. The stream only flows seasonally during the winter months, although when the base flow is absent sewage from Mexico would follow the path of the creek, if it were not for it being diverted for treatment. A alluvial fan formed at the northern mouth of the gulch, due to colluvium deposits. A natural spring had existed within the gulch. At some point in the past, before 2015, the stream was funneled into a 20 ft wide agricultural channel which flows into the Tijuana River this channel is connected to the gulch via an earthen channel which ends at Monument Road.

History
Dating back thousands of years before the arrival of Europeans in the Americas, the Kumeyaay lived in the area in and around the gulch. Melijo, a Native American village, existed north of the gulch; some of its inhabitants took part in the 1775 attack on Mission San Diego de Alcalá. During the Mexican period, the gulch was part of Rancho Melijo. Following the Mexican–American War, monuments were placed along the Mexico-United States Border; monument 256 was placed near the gulch. The canyon began to be referred to as Smuggler's Gulch as far back as the 1880s, due to smuggling of livestock from Mexico into the United States. Other items smuggled through the gulch were cigars, and lace undergarments. In 1889, a schoolhouse was built near the mouth of the gulch, and continued to operate until 1941; prior to its closing, it had been the southwest most school in the United States.

In the early 20th Century, prior to the American entry into World War II, about a dozen families settled within the gulch; they included the Satterlee, Welcome, Smallcomb, Brehlmeier, and Coones families, with most involved in agriculture. After World War II, mining occurred within the gulch. By the 1970s, significant croplands which had existed with the Tijuana River Valley began to be abandoned, with exception to those near the mouths of the gulch and nearby Goat Canyon. Beginning in the 1970s, contaminated water began to flow through the gulch, due to uncontrolled development that occurred as Tijuana began to grow into the gulch south of the border. In the 1980s tens of thousands of people illegally immigrating into the United States, passed through the gulch, and were subject to rape and robbery by criminals who targeted them; the next decade, the gulch continued to be a common route for smuggling of illegal immigrants into the United States. National Geographic referred to the gulch as the "prime route" for illegal entry into the United States during the 1990s. At the heights of its utilization for illegal entry into the United States, more than 10% of the 1.2 million apprehended illegal aliens were captured within the gulch.

Beginning in the latter half of the 1980s work began to collect sewage flows within the gulch, however it was insufficient to capture all of it, with over 100,000 USgal continuing into the estuary every day in 1987. In the 1990s, the City of San Diego purchased land at the mouth of the gulch, and utilized as a toxic waste dump, importing contaminated soils from Sorrento Valley. By the mid-1990s, millions of gallons of sewage were flowing through the gulch, leading to additional attempts to mitigate the issue by construction of additional pumps and pipes to the then-newly constructed International Boundary Wastewater Treatment Plant; however these pumps are insufficient to collect the polluted waters from Tijuana when it rains, which then flow into the Tijuana River.

Barrier construction
In 1996, the United States Congress, approved construction of fencing from the Pacific Ocean to 14 mi inland along the Mexico-United States Border. In 2002, a Border Patrol agent died when her vehicle toppled down the gulch's steep slopes. In February 2004, the California Coastal Commission had construction of the Mexico-United States barrier halted, seeking the United States federal government to make additional environmental concessions in regards to border barrier construction; this action was criticized in The American Spectator. Beginning in 2005, environmental laws were waived, as authorized by the Real ID Act, in order for the Mexico-United States barrier to be built in the gulch, and in nearby Goat Canyon. These proposed actions were criticized by various people and organizations, including the Sierra Club In 2005, while there had been existed a fence made of corrugated landing strips, 127,000 illegal aliens were apprehended in the area. In August 2008, barrier construction in the gulch began; work was contracted to Kiewit Corporation.

In July 2009, work was completed on the project in the gulch; it cost $58 million, and utilized 72,000 dump truck loads to fill in the 230 ft high gulch. The amount of dirt moved was about 2,100,000 cuft; the dirt came from the mesas nearby the gulch, within Border Field State Park. Atop the 3.5 mi long fill, is a road, lighting, and a triple barrier. The filling of the gulch is one of the most expensive parts of the Mexico-United States barrier. At the base of the filled in portion of the gulch are two 10 ft by 10 ft culverts to allow water flow.

In 2010, irrigation was installed on the fill, to encourage growth of vegetation to reduce erosion, which would assist in stabilizing the earthen fill. Beginning in October 2011, native vegetation began to be installed by United States Customs and Border Protection in order to rehabilitate areas affected by the installation of the border barrier across the gulch. After the barrier was completed in the gulch the area has been described as "nearly impenetrable"; however, even with these alterations to the terrain, it has not stopped all smuggling. As recently as June 2019, a small number of people have continued to evade CBP agents within the gulch. Due to the decrease of people crossing the border in the gulch, sensitive areas in the Tijuana River Estuary are no longer trampled on.

Following the construction of the border barrier in the gulch, a water channel was created to allow water from the gulch to flow into the Tijuana River; this channel is dredged and excavated yearly to remove trash, debris, and sands, which clog the channel. These items that are removed originate from Tijuana are waste from various sources, including hospitals, and home construction. A sediment basin was built in the gulch in 2006; when the basins are emptied about 15,000 cuyd of trash and sediment are removed;  removed sediment is deposited in a former quarry located in the Tijuana River Valley.

, the gulch south of Monument Road, and north of the Mexico-United States barrier, is owned by the County of San Diego.