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History

History

 

Hill Country Flood in September 1952

 

The following information about the September flood of 1952 highlights intrinsic characteristics of drought and flooding in the Hill Country. Large amounts of precipitation fall in a very short time. Most of this rainfall is shunted off the land before plants, animals or people can effectively use it. It is important to retain as much of this moisture high up in the landscape as possible to prevent damage from flooding and drought.

 

Drought

 

This particular flood happened during a time of extreme drought. According to the records of the Lower Colorado River Authority, Lake Travis’s all time low is 619.06 feet, recorded on September 6, 1952. The Llano River at Llano had virtually dried up in August, requiring the city of Llano to ship in water on train cars. The federal government had sponsored a program called “Operation Haylift” to ship hay from Iowa to Texas and there were very little crops being grown in Texas. Many Hill Country streams were at their all time record lows. Texas in the early 1950s was a very dry place in need of a reprieve.

 

Rainfall

 

In September the Hill Country received torrential rainfalls exceeding 20 inches in 48 hours. On September 9 gentle showers settled the dust with 1-3 inches of rain over various counties. Then the gentle showers turned into the heavy deluges that this area is known for, ranging from 3-8 inches across the Hill Country. On September 11 Blanco received 17.5 inches, Hye 20.7 inches, Llano 12.5 inches.

 

The Blanco River at Wimberley had only 11 cfs flowing on September 10 at 4 A.M. At 8:30 am on September 11 the river had rose to 30.10 feet and attained a peak flow of 95,000 cfs. In San Marcos, the floodwaters from the Blanco caused the San Marcos River to flow backward. The backflow of the San Marcos River over topped the highway 81 bridge. Once this extreme amount of runoff enters the river it is lost and cannot do its job to mitigate drought conditions. It may sound unrealistic, but much of this runoff could have been mitigated with just a few percentage increases in soil organic matter. For example raising the soil organic matter by 1% on one acre allows the soil to hold an extra 25,000 gallons of water. Raising it 1% on a 1000 acres yields 25,000,000 gallons of water storage in the soil, or around 75 acre feet of water volume stored in the soil via soil organic matter. We can also preserve our current water storage capacity in the soil by protecting the soil from erosion.

 

The Pedernales River received the most intense runoff of this event; 15 inches of rain fell in Fredericksburg, 26 inches down poured in Stonewall and Hye. The Pedernales at Johnson City had no flow on September 9th and on September 11 achieved a new record flow rate of 441,000 cfs and a new peak height of 40.8 feet. The USGS noted that cypress trees 5 feet in diameter “were broken off like matchsticks” and pecans 2ft in diameter were uprooted and washed away. This is reminiscent of the 2015 Memorial Day flood on the Blanco River in Wimberley where the cathedral of cypresses was lost and the landscape changed dramatically. The flood scraped the river bottom down to bare rock. The bridge on Highway 281 over the Pedernales had lost large sections and beams. Lake Travis gained 701,000 acre-feet in a single day, nearly tripling its volume in 24 hours. The level of Lake Travis gained 57 feet and filled the lake for the first time in seven years. Lake Travis did a great job of harvesting this floodwater and at the same time has been able to provide water to people during times of drought. However, the risks involved with this amount of water storage far exceed the benefit and only treats the symptom of the floods. In order to mitigate to high financial cost of flooding and the further degradation of our riparian areas water should be encouraged to infiltrate into the soil with all appropriate means as high up in the landscape as possible. This helps dissipate the high energy of the water in riparian areas.

 

No Drought Relief

 

Despite the intense rainfall, drought conditions persisted in the Hill Country and all of Texas. There was little to no rain reported for the entire month of October. This highlights the cycle of drought and flood in central Texas. Water storage capacity in the soil can be improved with polycultural forestry, intensively managed grazing systems, appropriate earthworks or a combination of all. Harvesting water high in the landscape via infiltration turns the problem of intense rainfall and flash flooding into a profitable and sustainable solution. Extreme flood events like this should be stored to mitigate drought, storing it in the soil is the cheapest and most effective way to do so. Instead the flood of 1952 caused damage to the soil that further degraded out water storage capacity in the soil. One Farmer in the Hye area had as “Fine a field as to be found in Gillespie Country before the rain. Now the field is just gravel and clay since all the topsoil was washed away.” This farmer’s field like many, is now less drought resistant than before because of the loss of topsoil which is rich in organic matter that holds tons of soil moisture, 113 tons of water per acre for every 1% organic matter. Subsoil’s that are exposed to the elements also erode more quickly and allow less infiltration resulting in increased runoff which exacerbates flooding. Optimizing lands ability to harvest water requires 100% ground cover 100% of the time. Damaging floods will be ended by ending bare soil.

 

Pete Van Dyck

 

Sources

“Flash Floods in Texas” Jonathan Burnett 2008

 

“Chapter 1 The Climate” Regrarians eHandbook 2015

 

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1082147.pdf

 

Photo:http://www.theatlantic.com/national/archive/2015/05/wimberley-texas-flood/394307/

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Climate and Geography

Flood Proofing the Texas Hill Country

Climate and Geography

Flooding in the Texas hill country is largely a result of the locations unique climate and geography. In the fall of 2016 Leslie Lee wrote for the Texas Water Resource Institute:

“Major flash floods are common along the Balcones Escarpment because of two factors prevalent in the region, according to experts: intense rainfall events and efficient drainage off the landscape.

“The region has some of the highest flood discharge per unit area of a drainage basin in the country,” said Dr. Richard Earl, professor in Texas State University’s Department of Geography. Earl, who joined the department in 1991, has studied flooding hazards for decades and has experienced numerous floods in San Marcos.

High rainfall intensities are common in the region because there’s an infinite source of moist air from the Gulf of Mexico, he said.

Over Texas, these moist, warm air masses from the Gulf collide with cool air masses from the north and moisture flow from the Pacific, said Dr. Nelun Fernando, hydrologist at the Texas Water Development Board (TWDB). When warm and cool air masses combine, it results in instability as the warm air rises above the cool air. Additionally, the Balcones Escarpment’s hilly terrain acts as a “ramp” for the fronts and “enhances what was already taking place between the two air masses,” she said.

“The rising air condenses and that creates rainfall,” Fernando said. “That effect gets concentrated over the Balcones Escarpment, and if very slow-moving frontal systems come through, such as what happened with the 2015 Memorial Day storms, then this constant stream of moisture from the Gulf will produce many inches of rainfall over a short period.”

This is called an orographic effect, where a change in elevation causes moisture-laden winds to deflect upwards and cool, resulting in rainfall, said Dr. Robert Mace, TWDB deputy executive administrator for water science and conservation.

“The transition between the Gulf Coastal Plain and the Hill Country is recognized nationally as a place where topographic changes cause these intense, localized floods,” he said.

Combined with its propensity for intense rainfall, the region’s rocky topography makes it flood-prone.

“The Hill Country is karst terrain, so it’s limestone that tends to erode in beautiful ways, but along with that beauty you get thin soils, hard surfaces and steep hills, and that all serves to funnel rainfall very quickly into restricted valleys,” Mace said.

Such terrain is created by the Balcones Fault zone, expressed on the surface by the Balcones Escarpment, which “goes through the heart of Texas,” Mace said. Along the escarpment and in areas just north and west of it, almost the entire landscape is sloped.

“It is fluvially dissected, which means that when it rains, the water doesn’t sit there — it runs off into the streams,” Earl said. “That’s hydrologically efficient drainage. When it rains, it just rushes into the streams and you get really intense increases in the amount of flow in the stream.”

Clay-rich soil types in the region are another contributing factor because once they are wet, clay soils have low infiltration and high runoff.

“And, much of the rural landscape is overgrazed,” Earl said. “Combine that with the fact that there’s increased impervious cover around cities and suburban areas — all of these things work together, almost in perfect combination to result in extreme floods.””

While this article states that there is an infinite supply of warm and moist air from the Gulf of Mexico there are also times of drought in the hill country. Often intense rainfall delivers much of the years rain all at one time. Although the geography is efficiently draining like Dr. Earl said, the karst limestone and high calcium soils also have a high rate of percolation. Karst limestone is much like a sponge, full of fissures and a honeycomb of holes that create underground rivers, water cannot pool on the surface for long because of the permeability of the bedrock. The high calcium soils in the hills have the ability to infiltrate water very rapidly because the clay particles in high calcium clays stand apart electrochemically. This is why ponds built in caliche do not hold water unless there is an existing high water table. These conditions give the opportunity for heavy rainfall to be pacified and infiltrated if the water can be slowed, spread, and sunk into the soil. The geography and soil conditions of the uplands in the hill country can be used to harvest flash flood precipitation and used to recharge shallow groundwater and aquifers turning the problem into the solution. By using the limestone hills as water storage tanks it is possible to harvest enough water to keep the aquifers full and rivers running year round while also limiting damage from flooding. Many flood events produce enough precipitation to supply all the water that central Texas needs, it needs only to be harvested and stored high in the hills as long as possible.

Reducing runoff starting from the hilltops protects the already eroded and thin layer of topsoil and allows nature to use water for topsoil regeneration via organic matter production. According to the NRCS every 1% of organic matter in the first six inches of topsoil holds 27,000 gallons per acre. Protecting and regenerating our topsoil is key to preventing flash floods in the Texas hill country.

Climate of the Mind

It is also important to consider the climate of the human mind that occupies this region. Flooding in the hill country can be better understood by analyzing the way decisions about land management are made by the population, in general.

Hilltop Development in Lakeway, TX

The natural beauty of this region increasingly attracts more residents and development. Hilltops and plateaus are cleared and used as building sites, which not only creates impervious cover at the top of the watershed but also reduces the hilltops ability to absorb precipitation. The result is a lowered water table beneath the hills, and is exasperated by well pumping as population continues to grow. This increase in runoff gains incredible amounts of energy as it moves down the steep slopes. This high-energy runoff is then channelized in waterways, destroys riparian zones and the real estate adjacent. Overdeveloped waterways in the hill country no longer have stable riparian ecosystems that can buffer the damaging floodwaters because they have been replaced with homes, roads and amenities. Developments are designed and engineered around drainage, but can be balanced with designed infiltration and runoff mitigation.

Development on the Guadalupe River in Kerville, Tx

Rural landowners in the hill country have tremendous ability to harvest water and regenerate their springs. Overgrazing leaves hilltops barren and compacted. Runoff from overgrazed hills channelizes in waterways causing destruction in riparian areas. River terraces in agriculture are often left barren half of the year with no vegetation to allow infiltration of water into the soil. Bare soil created in ranching and agriculture contributes massive runoff and landscape wide dehydration. This is commonplace and generally acceptable in rural communities. However, it is now becoming clear that farming and ranching is more profitable when water is managed to increase soil fertility. Losses during droughts and floods can be mitigated and the integrity of the land is stabilized.

Both rural ranch lands and quickly developing suburban areas could benefit immensely by taking advantage of the unique climate and geography of the Texas hill country. Everyone has contributed to the flood and drought problem in some way, all need to work together to stabilize it. Both flooding and drought can be mitigated by thoughtful design and using the opportunities that nature provides.

 

http://twri.tamu.edu/publications/txh2o/fall-2016/do-you-live-in-flash-flood-alley/

http://droughtmonitor.blogspot.com/2016/05/central-texas-is-flash-flood-alley.html

https://permaculturenews.org/2015/09/22/groundwater-re-charging/

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1082147.pdf

http://voices.nationalgeographic.com/2016/12/07/water-in-plain-sight/

http://www.businessinsider.com/why-some-places-remain-in-a-state-of-drought-2016-7?r=US&IR=T

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Regenerative Grazing with Jaime Elizondo

Regenerative Grazing

“Fat cows, fat cows, fat cows.”

This is the mantra of Jaime Elizondo Braun of Regengraze. I found about Mr. Elizondo while attending the Texas REX with Darren J. Doherty, where he gave a presentation on regenerative grazing. This quick presentation left me interested and I wanted hear more about what he had to say. The cattle looked very healthy, he had tripled stocking rates, increased soil fertility and profits. I set out to visit his newest project in Waller, Texas for a 2 day Regenerative Ranching course.

Soil Fertility

The first day we talked about managing in such a way that carbon returns to the soil via photosynthesis. To Mr. Elizondo soil life, plants, and wildlife diversity are biological capital that we must always improve in order to obtain maximum profitability. He explained his experiences on the use of pesticides, herbicides, fungicides, chemical fertilizers and fire (making note that fire destroys mycorrhizal fungi). He made it very clear that these options will have seriously consequences for your ecosystem, but cattle could be used instead to stimulate all of the biology that we want.

Adapted Genetics

One of the biggest problems with cattle in Texas today is that they are not adapted for our high heat environment. This leads to all sorts of management problems that require cattle owners to feed to maintain good body condition when they should be breeding for good body condition. Because many are not heat adapted they suffer and require pampering. Cows with adapted genetics will require less pampering and thrive when hard times like drought or flood comes, calve year after year, maintain body condition on low quality forage, and live longer.

Non-selective Grazing

Mr. Elizondo went into depth on the differences of selective and non-selective grazing. Selective grazing happens when an animal has continuous free range, the cow will select the tastiest plant and take a bite, she will continue to select all the best forage first and leave all of the unpalatable plants standing. This favors the undesirable plants. Non-selective grazing requires a higher level of management, but the results are visibly positive. The cattle are moved across the landscape at high density so that they are forced to eat or trample all of the plants. During this time the hooves roughen the soil, manure is dropped evenly in the pasture, and then the pasture is rested until it is completely recovered its growth. This prevents the overgrazing of desirable plants and encourages strong root development. Overgrazing is a function of time, not severity. It happens when animals re-graze a given plant before it has replenished its reserves. After one grazing the plant must have time to recover before being grazed again. Pastures with diverse species will require non-selective grazing to maintain an even playing field for the diverse species to grow even more diverse. Non-selective grazing cannot be done well with non-adapted cattle that cannot survive on pasture in the heat. Imagine the buffalo herds, a native adapted animal moving at high density through the prairie, being moved constantly by wolves and the need for fresh forage. Their dung and urine spread evenly in their wake. Nature required them to be tough through natural selection. To mimic this we will have to confront many of the paradigms that we have today about cattle breeding. Instead of managing for the maximum profit per animal, we must manage for maximum profit per acre. Imagine a corn farmer only trying to grow the largest ears of corn instead of trying to grow as many average sized ears of corn as possible on the farm. In regenerative design we take this even further by diversifying. We grow trees, vines, shrubs, herbs, root crops, small animals and large animals. By layering many elements we are able to manage for maximum sustainable production, but our maximum continues to grow as the ecosystem is served.

When we were not in a classroom we were out in the field observing the rangeland, the cattle or the infrastructure. The ranch had been conventionally grazed before Mr. Braun took over management. The pastures had obviously taken a beating. In the better pastures Bermuda grass, sweet clover, ball clover, plantain, rescue grass, rye grass, and vetch were in abundance. The more abused pastures were mixed with Bermuda and ragweed. The herd was mixed with many varieties of cattle. Many of them looked great, but there were many non-adapted cattle in the herd that did not look so good. The best-looking cattle were the mashona and mashona mixes. These are heat-adapted cattle that are very docile and maintain good body condition even during hard times. I had a newborn mashona calf come right up to me and give me a nuzzle, it was wonderful and really spoke to how friendly this breed is with people. None of the other cattle came close and some were skittish enough to make the whole herd run. The ranch had attempted using electric fencing before, but had failed because of improper grounding. Improper grounding is one of the main issues with electric fencing failures. Because of this failure they had built miles of barbwire fence that was still in place. Mr. Elizondo uses 5/8” fiberglass fence posts bought from Kencove, with a hole drilled through the post at the top and simple wire tie. The hot wire is high tensile galvanized wire, for gates he uses 8 ft PVC pipe probably 1 ½” with notches on the end of the pipe that prop up the galvanized wire. These “gates” can be easily moved and just lower the wire once removed. The cows have access to a laneway that leads them from any pasture to a water trough. The trough is a large galvanized tank with a float valve on it. They had been using a Great Plains no till seed drill to seed all of their pastures, it looked like they were having really nice germination seeding directly into Bermuda grass. I would like to try this and also incorporate many medicinal herbs and other valuable native plants, both as forage and for harvesting.

Overall I think Mr. Elizondo runs a very tight operation, he was extremely professional and kept my attention throughout the course. I definitely recommend Mr. Braun for educational courses or consultancy, his knowledge is expansive and tried through experience. However, he made it clear that if you wanted to really make this kind of animal impact you would need at least 200 cows to make ends meet, unless you had another source of income. As with anything, implementation of a grazing system of this magnitude has to be thought out and context has to be considered. The benefits are obvious with this way of grazing, but how can we incorporate this style of grazing into our polycultural systems? How can we stack functions and revolutionize even further? I think that a smaller more highly managed property could use this type of grazing system, but with lesser animal numbers it will be critical to have other sources of income or a strong direct marketing plan. While grazing is a really comprehensive large-scale land management tool, you have to be ready to have high initial land investment, select/breed adapted cattle, have extensive infrastructure (water, fencing, forage) and the will to commit. My hat is off anyone who can make this happen. It’s my dream to one day make an impact of the full scale ecosystem spectrum, hopefully one day it comes true.

We need more ranches in Texas adopting this style of management so that our soils improve on a broad scale, instead of degrade. This could have incredible impacts on our drought and flooding challenges since every 1% of organic matter per acre in the soil holds 27,000 gallons of water. Regenerative grazing has great potential to drought proof the state of Texas.

Visit the regenerative grazing website Here

Visit the Regengraze Facebook page Here

Joseph “Pete” Van Dyck

May 2, 2017

 

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