At meetings well over a decade ago, the Community Flood Coalition’s Flood Management Working Group conceived the idea to replace the old Virginia Street Bridge over the Truckee River with a new clear span Bridge.  The Flood Coalition was acknowledging that the then existing double arch bridge with its center support obstructed river flow during flooding events increasing flooding when water backed up behind the bridge into streets and buildings in downtown Reno. However, there were serious objections to removing the bridge because the early 1900s Virginia Street bridge was a historic structure and an iconic symbol of downtown Reno where new divorcees would toss wedding rings into the Truckee River as a symbol of their new freedom.

Many years later, the City of Reno and the Flood “Authority” decided to replace the bridge with a “suspension” style bridge – based on the need for improved flood protection for downtown Reno and the deteriorated condition of the old Virginia Street Bridge. The design was one that had met with approval from many citizens; however, the opposition to removing the old bridge remained. Many people who valued the historic structure lament its passing. As far as I know only the light posts on the old bridge were salvaged and installed on the new bridge. The earth-filled, concrete structure couldn’t be saved.

The celebration in downtown Reno of the new bridge featured live music, historic cars from the National Automobile Museum, and a large crowd of Renoites, City Council members, and  the President of Q&D Construction whose company built the bridge. Art work by Tutto Ferro is installed at a new river level area connected to the events plaza by a double set of stairways. One of the bronze-colored art pieces depicts the entire Truckee River from Lake Tahoe to Pyramid Lake. Another one shows Pyramid Lake’s bathymetry and the relief of the surrounding mountain ranges. Also, a the state of Nevada is given in relief showing its many mountain ranges and valleys.

The bridge features a large deck with a sidewalk on both sides giving walkers nice views up and downstream on the Truckee. The suspension arch – above the roadway – leaves a completely clear span under the bridge for water to flow during high and low flows. Other bridges in Reno now will impede flood water far more than the new Virginia Street bridge.

A welcome message was an artist (at least it looked like an original painting to me) reminding the crowd that the Truckee River flowing under our feet ends up (or it should) at Pyramid Lake. The Tahoe – Pyramid connected river system is unique in the west with a river leaving a very large lake and ending up in a very large lake. We here in Reno and Sparks have a connection to the Truckee River – a lifeblood of our communities – supplying water and all the green spaces that we enjoy as residents of the Truckee Meadows. The Truckee River is, too, the lifeblood for the Pyramid Lake Paiute people who have lived there for millennia. The Lake is their home and the Lake can’t exist without the Truckee River flowing enough to keep it alive.

Late in the evening on April 9 during a sub-tropical storm system producing mostly rain and showers in California and Nevada, Lake Tahoe once again went above its rim and connects to the Truckee River at Tahoe City. The Lake has been below its rim since fall of 2014. The Lake has risen more than 1.5 feet since its low in the late fall of 2015. How high will the Lake rise? That will depend on how fast the snow melts and whether or not we receive additional rain and snow this spring.

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• Spring arrives after a so-so winter for western Nevada

California news outlets report that the April 1, 2016 snow surveys show that the snowpack is running slightly above to slightly below average in the northern and central Sierra Nevada and decreasing to around 75% as you move southward along the range. Southern California and southern Nevada and Arizona have below average snowpacks reported by the California Resource Agency and the US National Resource Conservation Service for April 1, 2016.

Scientists with the Desert Research Institute say this result is opposite of what would be expected for an El Niño year where more precipitation should occur in the southwestern US – southern Nevada, Arizona, and southern California – and drier conditions to the north – Washington and Oregon. (See  winter forecast article from last fall.)  Winter 2015-16 saw precipitation trending higher in the Pacific northwest including northwest California instead. Why? Scientists do not currently have an explanation for the switch. Most snowpacks, however, are just at or below average in many north western locations.

The trend did produce an average water year with a less than stellar snowpack on April 1 in the Truckee River watershed in both the Sierra Nevada and Carson Range west of Reno and around Lake Tahoe. As I write this, Lake Tahoe is still about 1.5 inches below its rim, but rising as the snowpack melts under very warm spring conditions. Flow for the Truckee River this year is likely to be below the long-term average, though, because the entire Truckee River watershed has been in deficit over the last 16 years. Currently, the Truckee River is flowing at around 800-900 cubic feet per second (CFS). However, 300 CFS is diverted away from Pyramid Lake reducing flow to Pyramid to 500-600 CFS. Pyramid’s large water deficit over the past 16 years is likely to continue in 2016.

At the April 5, 2016 Climate Forum, scientists talked about the anomalous nature of precipitation for this year’s El Niño. However, El Niño did produce warmer conditions as would be expected. This winter was overall very warm and the departure from the long-term average temperatures continues up which is in keeping with global temperature rises.

In a brief presentation on the region’s climate looking to the future, Dr. Kelly Redmond from the Desert Research Institute, explained that as of now humans have added 25% more CO2 to the atmosphere and that the CO2 will remain in the atmosphere for a long time – one or two millennia. It is simple physics that CO2 has changed the heat balance of the atmosphere and that more heat is being retained now and will continue until a new, warmer overall equilibrium for the earth’s atmosphere is reached.  Other scientists said warmer conditions also lead to increased evaporation and evapotranspiration by plants. Even if precipitation remains the same, warmer temperatures mean less water will be available for rivers and streams and groundwater recharge as a result.

At the Climate Forum Dr. Benjamin Hatchett from UNR discussed long-term drought that occurred in the past.  Droughts lasting 240 and 140 years occurred between 832 – 1299. Are we prepared for such events should they occur again?  Clearly the late 19th and 20th centuries produced more average precipitation for the west than the beginning of the 21st century has so far. Could a “mega-drought” be in our near-term future? Climate models are not showing a huge swing downward in precipitation, but warmer temperatures will exacerbate droughts. How can we as a society do a better job of using water in both good and poor water years?  Can we adapt to warmer conditions and still maintain the environment? Truckee River flows? Pyramid Lake? Area streams and springs? Forests?

There seems little doubt that warmer conditions alone will require a much more thoughtful approach to water use if we expect future Nevadans to enjoy a healthy Truckee River and sustained Pyramid Lake and Lake Tahoe.

Related articles across the web

• California Snowpack Returns, But Fears Held For Future
• Hotter Spring Predicted by NOAA for Most of the Country
• Spring arrives after a so-so winter for western Nevada
• Get Used to Skimpier Snows in the Sierra