Spring 2012

St. Mary River Irrigation District's water start-up for the 2012 season has been tentatively scheduled for May, 1st (weather permitting). This is for water delivery at the farm gate.

Board Of Directors Elections 2012

Goerge Lohues has defeated Les Enns for the Board Member of Divsion 3.

Gerard Oosterhuis has been declared the Board Member for Divsion 6.

Chairman's Message SMRID Early Startup Considerations

Lately I have had a lot of questions regarding the startup of our Irrigation system for 2012, the most common one being, “Why does SMRID startup so late every year?” It is a recurring but important question that deserves an answer. It is also a matter that appears to be poorly understood so I will try and summarize the factors that have to be taken into account by both the Board and our Staff in making the decision of when to start each and every year. It is never a simple matter and always has some risks associated with it.

I must start with the statement that there is no institutional bias at SMRID against early startups! The Board members, who are irrigators themselves, clearly understand that in most years, there are many advantages to early seeding. SMRID also owns a 75% majority share in Irrican which benefits from early startups and long pumping seasons. SMRID exists to provide the best service possible to our rate-payers, the irrigators.

I farm on Class 4 and 5 soils north of Grassy Lake in a micro-climate zone that is often dry in the spring, with sandy soils that dry out quickly. I and SMRID Board member Bob Dykstra from south of Burdett, are consistent advocates of early SMRID startup dates every year. But to be more accurate, we are consistent advocates of “as early as feasible“ irrigation startups every year!

That modified phrase, “as early as feasible,” is at the core of the startup issue every year. While starting the system early each year may seem to some to be a simple undertaking, in reality it is far from simple and there are many factors involved and in some years, it is simply impossible or dangerous to do so. Each year the decision of when to start the system is completely different but always difficult, though for different reasons every year. I have been involved now for 11 years and 2012 is no different. It is a difficult and complex decision. I will try and help you understand the annual dilemma and the factors involved.

The first factor that must be considered is the readiness of the canal system. All repairs and rehabilitation projects must be finished ahead of startup. Sometimes, fall and winter weather conditions limit construction and projects must be finished in the spring. Sometimes there is damage to the main canal over the winter that must be fixed in the spring.

The next factor that must be understood is that the main canal flow cannot be just turned on and turned off if there is no demand or reduced demand for the water. There are timing and volume factors involved. From the time water is ordered into the main canal at St. Mary reservoir near Cardston until SMRID staff have all the laterals and pipelines charged ready to deliver irrigation water to the farm gates from Lethbridge down to Medicine Hat, about 2 weeks have passed. The decision to start the system has to be made 2 weeks in advance of the actual need. Likewise, it takes time to stop the system, although the time is probably only about one week.

Once the main canal is charged and flowing, there are about 10,000 acre-feet of water already committed just in the main canal, not the laterals. Once started, it cannot be just turned off; it keeps coming and that huge volume of water has to have a “home”, either onto farmers’ fields or into the various downstream reservoirs along the main canal. Ideally, staff end the prior irrigation season with each of these reservoirs at about 75% of FSL or Full Supply Level. This level is usually chosen because it is a compromise between having enough in storage for the coming season and still leaving room for spring runoff which cannot be stopped from entering our system from overland runoff when it occurs.

If the main canal is started and then wet or cold weather occurs and irrigation demand does not materialize, there has to be sufficient storage capacity in the system to absorb the flow. Adjusting the main canal flow to accommodate early demand is very tricky because pre-seeding and post-seeding irrigation are often light and of minimum duration. But the major consideration is always whether or not there is storage for the 10,000 acre-feet of flow once it is started because it is impossible to predict in advance what the actual demand will be 2 weeks later.

We witnessed firsthand how large a quantity of water that 10,000 acre-feet could be when we had our main canal break in the Purple Springs area in 2005. That break spilled a huge quantity of water out on the land below the canal and spread out over a large area and that was only a fraction of the 10,000 acre-feet because the flow between Ridge Reservoir down to Horsefly Reservoir was all diverted into Horsefly. Luckily there was room in Horsefly for it and “only” the flow from the Horsefly check down to the break flowed out onto the land.

There is another 10,000 acre-feet flowing in the distribution system of laterals and pipelines that must have a home also. Together, the total is 20,000 acre-feet. Early startup means a major commitment of flowing water and if that flowing water suddenly does not have a home, either on fields or in our reservoirs, there will be damage. That damage can be severe and deadly as was demonstrated last year when, in early April, the Seven Persons Reservoir emergency spillway washed out due to excessive storm-water flows entering our system further up the main canal.

Another complicating factor is the huge size of the district and the length of the main canal which is a little over 300 km long. That factor alone makes the decision difficult -- just because one area is hot and dry and needs early water does not mean that other areas are in the same situation. The needs of the drier areas must be balanced against, not only the needs of other areas, but also the constraints of the entire system running through all those areas.

When total available water in storage and projected river flows are tight and water allotments are restricted, every acre-foot of water is precious. If we start the system early and then due to rain or cold weather, we have to shut down, and if there is not enough down stream storage, that water is simply wasted or spilled and that sometimes occurs despite our best planning. In years when water supplies are tight, the need for early irrigation must be balanced against the need for heavy irrigation later in the main irrigation season which is usually hot and dry.

When cold freezing weather comes after the system is started, there is the potential for damage to the above-ground pipeline valve assemblies and air vents of which there are about 1500 or more. In addition to the replacement cost, which can exceed $1000 per valve, in some situations, the entire pipeline has to be drained in order to conduct the repair, which takes time. These are not minor considerations and we have experienced them.

Weather forecasts are the last consideration I will speak about, although there are yet others that I could mention. Given the lead-time required to fully start the system, and the amount of water required to be committed, weather forecasts must of necessity be consulted and considered in making the startup decision every year. Once startup occurs, if it turns wet and cold and the irrigation demand either does not materialize or drops off quickly, that water has to be dealt with. It cannot be ignored. Early irrigation is typically light and of short duration whether before or after seeding. This also complicates the decision in determining how much flow to introduce into the main canal. Often the initial canal flow demanded is of short duration and once more, the downstream storage capacity becomes an issue.

As of early April 2012, our downstream reservoirs are a comfortable level of about 75% of FSL, adequate to absorb startup main canal flows if the initial irrigation demand falls off. However, the limiting factor this year is some repairs to damage on the main canal in the Sauder area that will only be complete by mid-April. The last snowfall varied greatly between Lethbridge and Medicine Hat giving the unusual result that Lethbridge is now very dry and the closer you get to Medicine Hat, the wetter it gets instead of the usual vice-versa.

The Board has consulted with Staff and together we have determined that our startup date for the main canal out of St. Mary reservoir will be about April 13 giving a Target Date for farm-gate deliveries of May 1, 2012 which is actually about a week earlier than the long-term average. If it turns cold and wet before this time or forecasts call for significant precipitation, that target will be modified and announced.

This year, due to the above average condition of the mountain snowpacks that feed our rivers and the water currently in storage in all reservoirs, the Board has also announced that there will be No Water Rationing for 2012. There will be a full allotment of irrigation water up to the amount of our licensed river diversions.

LeRon Torrie

Chairman

St. Mary River Irrigation District

Alberta Agriculture Irrigation Management Section and The St. Mary River Irrigation District

will be conducting a series of one day Irrigation Management Workshops on

"Irrigation Management To Increase Your Irrigation I. Q."

Please click on this link for more information

Winter Rehab in the SMRID

Please click on this link for more information

Please click on the following links for the Government of Alberta's

Assessment of Water Quality in Alberta's Irrigation Districts

or Alberta Agriculture and Rural Development's Irrigation video

The Magic of Water

An Opportunity to share your views on "The South Saskatchewan Regional Plan".

The Government of Alberta is working towards the development of the South Saskatchewan Regional Plan. In May 2009, the Government established a Regional Advisory Council (RAC) to provide advice, insight and perspective on current and culture land-use activities and challenges in the region. Please click on this link to download a workbook developed by the council. This RAC workbook provides their advice about land uses in the South Saskatchewan Region, including recommendations on how to balance these uses and where choices are required. Your input on these recommendations is essential as the Government works to develop a draft regional plan. This workbook is designed to help you share your views on these important matters. Alternatively you may complete this workbook online at www.landuse.alberta.ca The SMRID encourages our water users to make their voices heard.

AQUISTION OF SMRID IRRIGATION ACRES 

The proposal for a 40,000 acre expansion of the District has been approved by a wide margin of the irrigators that voted on the plebiscite on March, 29, 2011. Three hundred and fifty irrigators voted representing approximately 20% of the waterusers. The final tally was 259 in favour to 91 against. Please Click here Who Can and How to Acquire Acres