Fire-prone

In 1910 a devastating wildfire tore through Idaho and Montana. In just two days’ time, the Big Blowup consumed almost three million acres of forested hillsides. Drought and high winds created the perfect conditions for a firestorm. The National Forest Service had recently been created, but fighting the fire required additional help from the US Army and the local miners. At last, a cold front brought a rain storm that put the fire out. Eight-nine lives were lost and the horrifying stories of the survivors motivated the country to create a fire suppression policy.

For most of the last century, the Forest Service put out almost every fire.  The result, unfortunately, has been severely increased forest density. The first settlers in northern Arizona described the forest as possible to ride a horse through at a full gallop.

Thick forest

Today riding at a gallop through the woods around Flagstaff would not be advisable. According to turn of the century reports from the early 1900’s, northern Arizona was mixed conifer forest with grassy undergrowth and large, open areas.  Because of the distance between the large old growth trees, when a wildfire occurred, it burned along the ground, not in the crown of the tree as today.  This allowed the trees to survive a fire, whereas today, everything is killed.

Burned hillside

You can see a burned off area at the top of this hill, with standing snags. The area below the hill was saved by fire-fighting efforts.

Arizona has a dry climate.  Arizona has experienced long drought periods in the past. When the Ponderosa Pines are distressed by lack of moisture, they are prone to the Pine Bark Beetle.  In 2010, 9.2 million acres (Out of 749 million acres of forest land in the United States) of tree mortality was caused by insects and disease. 74 % of that damage was done by the Bark Beetle. Once these stands of trees die, they are tinder waiting for the next lightning strike, careless camper, or tossed cigarette.

The problem is compounded by the number of homes built in the interface area between the forest and the urban areas.  Firefighters are put at risk to save homes from the fast-moving fires.  Much has been learned about caring for our wild lands, and one of the projects now underway is 4FRI. This is the Four Forests Restoration Initiative, working to restore the structure, pattern and composition of fire-adapted ecosystems, which will provide for fuels reduction, forest health, and wildlife and plant diversity. 4FRI aims to implement comprehensive restoration over the next twenty years, including thinning of predominantly small trees across one million acres, and safe controlled burning and natural fire management on much of the landscape.

Downed Ponderosas

Bark Beetle-downed trees

Dry slash pile

Slash piles ready for burning

Fire from car

A controlled burn

Hopefully 4FRI is a solution for implementing landscape-scale forest restoration. It is a problem that will take twenty years or more to solve, with new fires happening each year.  Home owners in the urban interface areas attempt to clear areas around their homes, and create emergency plans for escape should a fire start.

Dry

Because Arizona is arid by nature, we are tempted to think it has no water.  Since ancient times. residents of this desert land have been ingenious in harnessing the water resources needed for life.  As it was for the ancients, our main renewable resource for water is surface water in streams.

Petroglyph on Shaw Butte in north Phoenix

Petroglyph on Shaw Butte in north Phoenix

 

For almost 1500 years the Hohokam people inhabited central Arizona, farming near the Gila and Salt Rivers.  In about 600,  the Hohokam began to dig canals up to twelve feet deep to bring water to their 110,000 acres of fields.

Petroglyphs of the sun during the seasons of the year, Shaw Butte

Petroglyphs of the sun during the seasons of the year

 

Their amazing irrigation system made it possible to support a population of about 80,000 people.  We do not know what finally disrupted their civilization in about 1450, but they left petroglyphs on hilltops throughout the region.  Their descendants live on as the Tohono O’odham Nation.

In the 1870s, settlers to the central valley followed the lines of the ancient canals and brought water from the same Salt River to their own fields.  Those canals are no longer in use, but newer canals criss-cross the valley bringing water from the river and from new projects. Arizona has developed one of the most sophisticated water management programs in the world. (The Arizona Experience)

Beginning in the early 1900s, Arizona began building a series of dams along the streams and creeks of the state. Lakes behind these dams provide recreational use as well as water supplies for drinking water, irrigation and industry.

Roosevelt Dam on the Salt River was built in 1912.

Roosevelt Dam on the Salt River was built in 1912.

 

As it was for the ancient people, the surface water today is not dependable season to season or year to year.  Additional resources currently are Ground Water, Colorado River Water, and Effluent.  Water from the Colorado River is brought into the middle of the state with the Central Arizona Project, CAP, and used to fill the lakes and recharge the groundwater. Bartlett Lake lengthWith careful management, Arizona is not so dry after all.