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Medina Lake and Canal System Medina Lake was constructed between 1911-1912 as an irrigation reservoir. An extensive canal system delivers water to 34,000 acres of blackland prairie farmlands below the Balcones escarpment around Castroville, La Coste, Natalia, and Devine. Portions of the canal extend to urban San Antonio, just outside Loop 1604. At the time it was constructed, it was the biggest irrigation project west of the Mississippi. At spillway capacity, Medina Lake covers about 5,575 acres, has a length of 18 miles, a maximum width of three miles, and 110 miles of shoreline. In addition to the main dam, there is a smaller dam about four miles downstream that creates Diversion Lake, from which discharges are made to the canal system.
Medina Dam, Medina Lake, and Diversion Lake were constructed partially on the Edwards limestone outcrop, so the lakes contribute large amounts of water to Aquifer recharge. Seepage losses from Medina Lake and Diversion Lake have been documented by the USGS and other sources since completion of the irrigation structures in 1912. All of the water lost from the lakes has been assumed to enter the Edwards Aquifer, either directly or indirectly through the Trinity Aquifer. In 2004, the United States Geological Survey completed a water budget analysis and concluded that an average of about 3,083 acre-feet recharges each month (Slattery and Miller, 2004). A Brief Historical Sketch
Although Dr. Pearson usually gets credit for building Medina Dam, it was not his idea, and several others were instrumental in the project. According to Rev. Cyril Kuehne, who published a historical account of the dam's construction in 1966 called Ripples From Medina Lake, the original dreamer was Castroville founder Henri Castro. The year was around 1850, and means were not available, but Castro assured his fellow pioneers that someday a great dam would be build to harness the Medina River's floodwaters and irrigate the land around Castroville. For decades, pioneers referred to the area that would become Medina Lake as the "Box Canyon". In 1894, Alex Y. Walton was on a hunting trip to the Box Canyon and, upon inspection of the natural contours, became convinced that waters could be held in readiness here and "according to the need for the service of man." He sought expert advice, and obtained enthusiastic support from engineers Terrell Bartlett and Willis Ranney. After completing surveys and engineering plans, they enlisted the help of Judge Duval West to prepare all the legal papers that would be required.
The pace of construction was frenetic, mostly because the builders expected large floods in the summer of 1913 that would fill the reservoir. The floods never materialized, and after construction was complete in November 1912, it was 18 months before any significant rains occurred. The Lake was not filled to capacity for the first time until September 1919. Whether the designers overestimated the rainfall or the size of the watershed is not clear, but what is certain is the Medina River watershed has simply never been able to supply as much water as they envisioned. Wildly fluctuating levels have characterized Medina Reservoir throughout its entire history. Medina Dam was only one component of Alex Walton's comprehensive master plan to establish town sites and sell land to prospective farmers. His group established the Medina Irrigation Company and laid out the town of Natalia, named after Pearson's daughter Natalie. But before land sales could be started, world events spelled financial disaster for the project. When England became involved in World War I in 1914, Pearson's access to British capital was limited, and the Company was placed in receivership. In order to make a personal appeal to British investors for more capital, Pearson and his wife boarded the Lusitania and perished when the ocean liner was torpedoed and sunk by a German submarine on May 7, 1915. After that, US federal courts did not allow any land sales, so the Company leased land until it was released from receivership. The stockholders preferred selling the Company to reorganizing, and there were several failed attempts to keep the endeavor alive, but all the subsequent corporations also went into receivership. Finally, in 1950, assets that had cost $6 million to build were sold for $10 and "other valuable considerations" to the Bexar-Medina-Atascosa Counties Water Improvement District No. 1 (BMA), which voters had established in 1925 to oversee the project. The BMA has continued to own and manage the project ever since. Note: (For a full account of the project's early history and construction, you can obtain a 1999 re-print of Kuehne's book from the Castro Colonies Heritage Association.
Early Tourism to Medina Lake
Diversion Dam in The Masked Rider, 1919
In the 1919 silent film classic(?) The Masked Rider, villainous Pancho (Paul Panzer), is so fed up with Texan ranchers on the other side of the border that he hatches a plot to blow the dam and drown everybody for miles around. A damsel that Pancho has taken captive (Ruth Stonehouse) gets a note to Texas Rangers in time for them to ride and try to save the day. A gunfight ensues, with lots of dangerous stunts on the dam. One of the lawmen being shot at is Lon Hildebrandt, an actual Texas Ranger. The scene is shot on Diversion Dam, not Medina Dam, so blowing it would not have drained Medina Lake. Maybe villains are just stupid, or maybe the producers saw that Diversion Dam was more visually pleasing and offered more opportunity for adventurous frontier escapades. For dam enthusiasts, the interesting part is a look at how the gates were operated manually to release water to the canal system. I stole this video from The Serial Channel on youtube. The video restoration was done by Eric Stedman, with music by Kevin MacLeod and screams by Wilhelm.
Medina Lake: Waters of Controversy Who owns and uses Medina Lake water and the land around the lake has become a nagging source of concern for local landowners. Many issues were brought to a head during the droughts of '96 and '98, and long-standing tensions between the BMA and local landowners escalated. The function of the BMA is to provide irrigation water to farmers downstream, and storing this irrigation water has been the purpose of the lake since it was built. But since the 1950's many people have purchased or built homes adjacent to Medina Lake and for decades have believed they owned lakefront property and that a lake would always be there. For a long time, it was, and a recreational economy grew up around the use of Medina Lake water. During the 96-98 drought years, many became concerned about low lake levels and were shocked to learn that their property boundaries were in dispute, they were unable to restrict access by non-landowners to the lake, they had no ownership of water, and they had absolutely no guarantee there will be any water in Medina Lake. The recreational economy was impacted by consistently low lake levels, and property values and some drinking water wells of lakeside property owners were also affected. The property boundary dispute involves who owns a strip of land between the elevations of 1072' and 1084' feet above sea level known as the 'Contour Zone'. The top of Medina Dam is at 1084', while the top of the spillway is at 1072'. The BMA claims it owns almost all the land below the 1084' line, while local landowners claimed the BMA only has the right to flood the land. Many landowners have built improvements or septic tanks in the Contour Zone, which they insist they are allowed to do "at their own peril". Since there is 12' feet of elevation between the tops of the spillway and the Dam, there is always a strip of land encompassing at least 12' in elevation between the lake level and the BMA-claimed property line. Low lake levels often expose a much larger strip of land adjacent to the lake that offers enticing party spots. So to make matters worse, people who own land adjacent to the Contour Zone often come home to find large boisterous parties happening in front of their homes. Many were in favor of having access to the land below 1084' restricted or eliminated. The controversy about who is allowed to use Medina Lake also involves people who own land in the surrounding hills. For decades the BMA has had an "open lake" policy. And policy aside, many in the hills nearby have deeds that contain language they claim allows them to use the waters for fishing and swimming. There are hundreds of roads that are used to access the lake; most are on easements and BMA property, but some cross private property. Many who own land adjacent to the "ten eighty four line" argue that since they pay much higher taxes, they should have exclusive use of the waterfront and use by those in the hills should be restricted or eliminated. People in the hills point to their deeds and to the open lake policy and say those adjacent to the lake are paying higher taxes because they are adjacent to the lake. In an attempt to resolve ongoing disputes about who has access, in April 2001 the BMA began seeking feedback on a plan to lease the land below 1084' to adjoining landowners for $100 per year. Hardly anyone seemed to like the idea. People in the hills argued they should also have the opportunity to lease land, not just those who own property adjacent to the 1084' line. Even some of those property owners questioned the proposal's fairness and whether BMA has the legal right to do it. In October 2001 another controversy resurfaced over public access to Diversion Lake. Although the waterway is public, its banks are privately owned and public access is restricted by Medina county. Arguments over who should have access have been going on for over 70 years. In Texas, when a public river is dammed, the resulting lake is public property, but only people able to reach it legally have a right to use it. The Medina Ranch, while recognizing the water is public property, owns both sides of the River right down to the banks and wants to protect its private property rights. The Ranch granted the county an easement for County Road 271, and the county maintains a fence that blocks access to the Ranch at the bridge where the road crosses the Medina River. The only public access to the waterway is from the bridge. The bridge was replaced in the summer of 2001, and debate erupted when a new fence was installed in October with gaps for public access only two feet wide. In May of 2004 Medina county officials made a field trip to review the 2001 fence project when new complaints were received. Even without the fence, there is still no public parking available. Texas Parks and Wildlife Dept. attorney Boyd Kennedy said that although the lake is public and boaters have the right to use it, there's no law that requires anybody to give public access to a public body of water. In April of 2003 the land ownership controversy erupted again when the BMA began testing its claim to ownership of all land below the 1084' contour line. The agency had received little support for its 2001 plan to lease land below 1084' to persons who had built structures on land they believed they owned, and it sued two Wharton's Dock residents for title and possession of the land under their homes. Residents all around the Lake began preparing for bitter legal battles. By July 2003, the BMA had completed surveys using extremely accurate global positioning satellites that clearly delineated where residents had built structures below the 1084' line. It also hired a researcher who concluded the land between 1072' and 1084', previously thought by many to be an easement, was owned by the BMA through fee simple title. Medina county tax appraisers agreed the BMA appears to have rightful claim to all property below the 1084' line unless landowners can show the property was purchased before BMA existed. BMA officials agreed that residents have a right to be angry, but not at them. They blamed the problem on developers, real estate agents, and county officials who allowed BMA land to be sold, platted, taxed, and settled. It seemed likely that persons whose land was condemned long ago for Medina Lake construction might have retained certain rights of ownership and/or use of the contested lands. It is not all that uncommon for landowners to be allowed to remain on and use land that is taken in condemnation proceedings. Whether or not such rights can be extended to hundreds of other persons when the original tract is subdivided is still a large unanswered question. More than 100 homes in Wharton's Dock subdivision alone are below the 1084' line. The BMA said it had the deeds, but attorneys for Wharton's Dock residents had a different interpretation of the same deeds, and indicated they would argue in court that the BMA's deeds only give them the right to flood the property. Residents formed a non-profit corporation, the Waterfront Property Owners Association, to advocate for the interests of landowners. In January 2004 the Waterfront Property Owners Association filed a petition for declaratory judgment, arguing that the BMA had embarked on a campaign to seize control of privately-owned waterfront property on Medina Lake. They were seeking, among other things, a declaration that BMA’s rights in the Contour Zone are limited to the right to flood in connection with the storage of water in Medina Lake for irrigation purposes. In November of 2004, an agreement was reached in a court-ordered mediation session that allows lakeshore landowners who voluntarily sign on to the settlement to have guaranteed access to the water and also allow them to fence off the shoreline against unwelcome visitors. Under the agreement, the BMA will convey to participating residents a perpetual easement to the land below 1,084'. In exchange for control of the waterfront, residents will pay an annual assessment fee based on linear feet of shoreline and also agree to have their septic systems licensed and inspected. Landowners had until March 1 2005 to sign on, and more than 300 did so. The ownership rights of those who did not sign on are still subject to challenge by the BMA. The pact did not address some major unresolved issues, including the validity of BMA's ownership claims, the agency's jurisdictional boundaries, and the extent of its regulatory authority over the Lake. Use of Medina Lake Water While controversy swirls around access and ownership, the future of recreation at Medina Lake also remains in question. Since Edwards Aquifer supplies are now limited by law, area water purveyors like the Bexar Metropolitan Water District and the San Antonio Water System have to look toward Medina Lake to help meet growing demand. It is one of the few places in the region where water can be stored to help meet the summertime peak demand. The idea is that excess water not used by the irrigators will be delivered for use in the San Antonio area and not left in the lake as it has been in the past. Low summertime levels in Medina Lake could become a yearly event. On the other hand, this situation could be mitigated to a large degree if recommendations made by the South Central Texas Regional Water Planning Group in their current planning document are implemented. What the Planning Group has in mind for Medina Lake is purchase and/or retirement of irrigated farmland and Aquifer pumping rights, which would leave more water in the lake to become Aquifer recharge. Lake levels would generally be higher which would benefit recreation, but the farming segment of the local economy could be impacted. And there are some other issues that would have to be worked out such as getting a recharge recovery permit from the Edwards Aquifer Authority. In November 1999 the BMA board approved a long-term contract with the Bexar Metropolitan Water District to supply 10,000 acre-feet annually, increasing to 20,000 acre-feet by 2012. Bexar Met picks the water up from the Medina River, then treats and distributes it from their surface water treatment plant that opened in February 2000 in southwest Bexar county.
As more of Medina Lake's water is directed toward municipal uses, maintaining water quality will likely become another controversial issue. It is not uncommon for gasoline-powered watercraft to be banned from water bodies that serve as a drinking water supply. Such a ban would surely raise the ire of boaters, but the alternative could be higher treatment costs for municipal users. Another issue that is likely to surface is what to do about septic tanks that dot the shoreline and discharge effluent which ultimately reaches the lake. Septic tank effluent contains nutrients and pathogens, and systems that discharge by gravity using a drainfield are usually prohibited near waterbodies. It will probably become necessary to remove or replace such systems with ones that evaporate the effluent to the atmosphere. During the drought of 2006, some farmers who had always relied on Medina Lake water were forced to find other sources or stop farming. On June 19, BMA Board President Tommy Fey sent a letter to customers announcing that at their current rate of withdrawal, the District would be out of water to sell by the end of August. Although most of the major crops such as corn and cotton were already finished irrigating for the year, the situation caused difficulty for vegetable farmers who plant in the fall to make products available around Thanksgiving and Christmas. The drought of 2006 also confirmed that BexarMet's supply of water from the Lake is not especially reliable. During dry years, not all of the 20,000 acre-feet that Bexar Met has under contract is available. Conversely, during wet years, not all of it is needed. In August of 2008, an alliance of 14 small cities called the Texas Regional Water Alliance received authorization from the Texas Water Development Board to fund a study aimed at examining ways to firm up supply from the Lake during dry years and store excesses during wet ones. Some of the methods that will be examined include storing water in small off-channel lakes along the canal, or injecting water underground for retrieval later. The idea is that if reliability and supply can be increased, the water could be available for Alliance member cities. Officials estimated the study should be complete by 2010. Infrastructure Issues For several decades, some major repair work was sorely needed on the Medina dam control structures. One of the 90-year-old valves that controls releases from the dam was inoperable, and the other two were rapidly deteriorating and could have failed at any time. There wasn't any danger that a life-threatening wall of water could rush down the Medina River, but if they were to fail in the open position the lake could drain in a matter of weeks; and if they failed in the closed position people who have rights to irrigate with the water would be unable to get it. The side of the valves under the lake hadn't been inspected and it was unknown if they needed extensive rebuilding. Under the 1999 water supply agreement with BMA, the Bexar Metropolitan Water District agreed to address several infrastructure issues including:
In June 2000 a committee recommended a plan to initiate repairs to the gates in early 2001. Under the plan, Gate 3 was plugged and new outlet piping installed on Gates 1 and 2. The plan also included removing debris from in front of the gates on the upstream side of the dam. The work did not begin until 2003 and while it began during a wet spring, it continued into a very dry summer, and farmers were unable to get water through the gates that normally control releases. They were so desperate to get water that heavy equipment was brought in to chip a notch into the spillway and large pumps were used to send water downstream. Meanwhile, back at the valves, debris removed included telephone poles and an automobile. It took three months to install the two new electrically operated, custom-made valves, but by November it was clear they were warped and leaking. Key parts had to be removed and sent back to the manufacturer for rebuilding. There was some finger-pointing between the manufacturer and the contractor who installed them, and the contractor's bonding agent eventually agreed to pay for the repairs. The valves had apparently been torqued too tightly during installation. After one of the valves was re-installed in mid-December of 2003, it still leaked more than 1,500 gallons per minute. In March of 2006, the BMWD approved a contract to draw up plans for installing an additional valve on each gate. The idea is the existing leaky valves will be used to regulate the flow of water from the dam, and the new valves will regulate the flow released downstream. More than $50 million in work is also needed on the hundreds of miles of canals that deliver Medina Lake water to 1,900 irrigators downstream. About 80% of the water that enters the canal is lost to evaporation, leakage, and theft. A September 1999 BMA report indicated that at that time 38,132 acre-feet had been released to the canal, but only 5,520 acre-feet had been sold. That means about 6.9 gallons were placed into the canal for every gallon sold. About 30% of the water diverted to the canal is lost to leakage in the first six miles of the canal alone. Another problem is that withdrawals operate on the honor system and there are no meters to record water usage. Some irrigators who use water from the canal take more than they pay for. In September 2000 the BMA received a $3.7 million loan from the Texas Water Development Board to line the upper six miles of the canal, a project that will cost about $6.5 million. The loan money will be used as the agency's half of matching funds for a federal grant. In September 2000 the agency also indicated that improving management practices was a priority. The Flood of 2002 In July of 2002, the safety of Medina Dam was called into question when a stubborn low-pressure system parked itself over the region and much of south Texas received almost a year's worth of rainfall in less than a week. Water more than 12 feet deep crashed over the spillway and the level of Medina Lake rose to within inches from the top of the Dam. Normally, dams are not constructed to withstand water going over the top; and if that had occurred, there could have been significant erosion that might have undermined the structural integrity of the Dam. On July 5 BMA officials, engineers from Freese and Nichols, and state and federal officials inspected the Dam and there was disagreement about whether it was safe. The inspection party was missing an important member...Chau Vo, the State's top dam-safety engineer, had been inadvertently left in a hotel room. He organized his own tour later that day and concluded he could not be 100% sure there was no danger. He advised the Department of Public Safety, which issued a public warning. County Judge Nelson Wolff went on TV that evening to relay the DPS warning about the Dam's safety. It resulted in the complete evacuations of Castroville and La Coste. Wolff's action came under heavy criticism from residents and BMA officials who claimed it was politically motivated and that people were needlessly scared. A subsequent check of the Dam concluded it was safe, but a report prepared for the TNRCC by Freese & Nichols issued a few days later contradicted this conclusion. The State report said that if water had gone over the top of the dam there could indeed have been a massive failure. It concluded that DPS was correct to issue a warning and Judge Wolff was correct in relaying it on TV. On July 11 engineer John King of Freese & Nichols released a list of 20 recommendations that included early warning systems, assessment of scour potential in various areas of the structure, and examination of alternative methods to prevent overtopping of the dam in the future. The controversy did not end there, however. On July 17 engineers hired by the BMA said the dam could have withstood water going over it 16 feet deep. One thing was for sure...the fiasco pointed out major flaws in the communication system that is supposed to warn residents of danger. Subsequently, lawmakers issued calls for new statewide dam safety inspection programs and ordered the preparation of another safety report for Medina Dam. Two years later, in October of 2004, the state-ordered study concluded the dam could topple over or slide downstream if overtopped by more than about six feet of water. Engineers recommended $2.7 million in improvements to stabilize the dam and prevent erosion, including anchoring the dam abutments into bedrock with cables and protecting the abutment's limestone foundation with several feet of reinforced concrete. By late 2006, the cost estimate had almost quadrupled to $11 million. With only about $3 million on hand for repairs, the BMA sought funding from federal sources and also from the Texas Water Development Board, but struck out on both occasions. In March of 2008, Bexar county announced it would commit $3 million to the repair costs, because a catastrophic dam failure would cause widespread damage in the southern part of the county. More than 50 square miles would be flooded and Toyota's truck manufacturing facility would likely be under water, along with two of SAWS' major wastewater treatment plants. To secure the remaining $4+ million, Rep. Tracy King proposed a bill during the 2009 Legislative session to give the BMA credits with the EAA for water that leaves the Lake and becomes Edwards recharge. The idea was the BMA could sell these credits to fund repairs. This plan was widely viewed as a non-starter, because the recharge from Medina Lake was factored into the water budget when pumping permits were issued. A second version of the bill proposed that instead of issuing recharge credits for subsequent sale, the cost would simply be divvied up among downstream interests. The bill was approved by the House but never made it out of a Senate committee before the session ended. The issue was resolved, however, when $4 million for repairs was included in the state budget, and in June of 2009 local authorities were expected to move quickly to develop a required interlocal agreement and get the repair process underway. In March of 2010, contractor bids were solicited for work designed to make the dam capable of withstanding an 11-foot overtop by floodwaters. Happily, a bid came in from the Austin Bridge and Road Company that was much less than the projected $11 million. For $3.7 million, the company will install 32 anchors that will pin the dam to the ground and also pour concrete aprons to keep the dam from slipping and tipping. Work began in November of 2010 and was expected to take about a year to complete. In July of 2011, two workers were injured when equipment used to pump grout under high pressure failed, causing pieces to fly.
Medina Lake Photo Gallery The pictures below are organized to take you on a "virtual tour" from Medina Lake down to the far reaches of the canal system:
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