Current Flow Conditions

Updated June 22, 2022

“Humorist Will Rogers, the story goes, once described the Rio Grande as “the only river I ever saw that needed irrigation.”. . . Yet as our flotilla meandered downstream past private ranch land and the Native-American-owned Santa Ana Pueblo, paddles occasionally tickling the Rio Grande’s soft bottom, the passing parade was anything but desolate.

“Snowy egrets and great blue herons minced along the willow-lined river banks, while a squadron of swallows wheeled close above the tea-green riffles of the gentle rapids.”

Laura Bly, National Geographic Intelligent Travel

Understanding Recreational River Flows on the Middle Rio Grande North of Albuquerque

 

Kayakers near Algodones, July 18, 2013 - Flows at 173 cfs

Overview

  • The Middle Rio Grande immediately north of Albuquerque (bordering Algodones, Santa Ana Pueblo, Bernalillo, Sandia Pueblo, Rio Rancho and Corrales) is navigable by paddlecraft most of the year, due to the much narrower, deeper river channel in this reach.
  • The wider river channel beginning 2 miles north of Alameda Blvd, coupled with the San Juan Diversion dam, translates into the presence of extensive mudflats and sandbars within the city of Albuquerque at flows below 700 cfs. It is the view of the river at low flows from the numerous bridges within the city that leads to the common misconception that the river can't be floated near Albuquerque.
  • The difference in width of the channel leads to dramatic differences in depth of water. Flows of 500 cfs will translate to 2' - 4' of depth in the 75' - 100' wide channel north of Albuquerque, but less than 12" of depth in the 450' - 600' wide channel in the city itself.
  • Flows of 700 cfs to 2000 cfs are ideal flow conditions for recreational outings here, and are present much of the year.
  • Flows above 3000 cfs do result in much more challenging conditions for beginners and occasional recreational paddlers
  • "The Bosque" is offered only at flows above 900 cfs, as most recreational paddlers do not possess the shallow water river-reading skills to successfully navigate the last two miles at lower flows.

This page was originally posted in the summer of 2013, when New Mexico's historic drought of 2010 through 2014 reached it's apex. In June of that year, as we were witnessing record low flows along the river, journalist Laura Bly joined us for an outing The resulting article (linked above) features several quotes from us addressing the prevalent misconceptions regarding the navigability of the Middle Rio Grande at lower flow conditions. As it was clear that there was absolutely no understanding in respect to recreational river flows near Albuquerque among the general population, nor among the primary local news sources, we decided to address the issue with this page.

In average and low snowpack years, we're constantly reminding folks that the river immediately north of Albuquerque is navigable most of the year due to the much narrower river channel in this reach. As a matter of fact, lower flows (500 - 1500 cfs) create a much more pleasant and forgiving environment, which is several orders of magnitude better for casual recreational outings. Lower flows also tend to add more visual interest to the river itself, as exposed gravel bars, entirely submerged at higher levels, create numerous glittering cascades as the river meanders along.

At higher flows (2000 cfs or more), most sand and gravel bars are submerged, so shallow water is less of an issue. Experienced river runners will definitely enjoy higher water.

On the other hand, faster current speeds and the resulting wider river channel does bring numerous hazards into play that can be very challenging for the less experienced. Low hanging trees are nearly continuous close to shore, obstructions in the river channel (jetty jacks, submerged logs and trees, old bridge pilings, etc) which are obvious at low flows, can be just below the surface, and strainers or other hazards, while easier for experienced boaters to avoid due to the additional width, are definitely more severe and require good anticipation and better boat control to avoid. Secondary channels also fill at higher flows, which can be fun to explore, but may also contain unknown hazards. Those choosing to head out at higher flows without guide support (rentals or Self-guided outings) should possess a solid understanding of river dynamics and must have the ability to immediately eddy out of current and get to shore at a moment's notice.

The primary cause of the widespread misconceptions is related to the dramatic difference in character of the river immediately north of the city (where we operate), as opposed to the reach through Albuquerque proper. From Cochiti dam to approximately 2 miles north of the Alameda Bridge at the northern city limits, the Rio Grande features a river channel that ranges from between 75' – 125' feet in width. This relatively constricted channel translates to sufficient depth for watercraft that displace as little as canoes, kayaks and SUP's, even at extreme low flows..

Two miles north of Alameda Blvd, immediately south of the North Diversion Channel Outfall Sedimentation Basin (a flood control diversion construction), the river channel widens to over 450', and braids into multiple channels. As the river continues south through the Rio Grande Valley State Park in Albuquerque, it widens further still, to well over 600' in some areas. Combined with the fact that the San Juan Diversion dam (immediately below the Alameda Bridge) removes a great deal of the river's incoming flow, the river within the city limits of ABQ may appear nearly dry at extreme low flows, yet the Rio immediately north, through Santa Ana Pueblo, Bernalillo, Sandia Pueblo, Rio Rancho and most of the way through Corrales, has plenty of water to float kayaks, paddleboards and canoes.

Determining accurate flow conditions has become more challenging since 2019's construction of a rock weir extending across the river at the Corrales Siphon, and the ultimate failure of the weir to prevent the collapse of the Siphon pipe beneath the weir, forcing MRGCD to pump water directly from the river to meet their Corrales water delivery obligations. It would appear that monitoring USGS 08329928 as we historically have, then adding back 75 – 100 cfs to account for the water removed at the San Juan/Chama diversion dam provides an accurate reading for the Bosque section (Corrales Siphon to Alameda).

However, the northern section (Algodones to the Corrales Siphon), is more accurately estimated by monitoring the last gauge north of the Angostura Diversion at Algodones (USGS 08319000 RIO GRANDE AT SAN FELIPE, NM), and then subtracting the diversion at Angostura. (use the second column with the heading "Angostura"). This does appear to be significantly more precise for those planning to enjoy the river north of Corrales.

For example, as of the date of this revision, the gauge we've previously used for the entire reach (USGS 08329928 RIO GRANDE NR ALAMEDA, NM) is reading 255 cfs. Adding 75 – 100 cfs to account for the San Juan/Chama Diversion gives us a range of 330-355 cfs. The recently calibrated - but often malfunctioning - Alameda Bridge gauge above the dam confirms with a reading of 373 at the moment.

Yet, when we look at San Felipe, the reading is 592. Subtracting the water removed at Algodones (135 cfs), leaves us with 457 cfs below the Angostura dam. This would indicate close to a 20% loss of flow between Algodones and Alameda. Whether that's due to the pumping station, seepage or a combination of factors, it's significant enough that we've added a second gauge to this page to track the "Coronado" section.

Coronado Flow Conditions (Algodones to Corrales Siphon)

USGS Water-data graph for site 08319000

For an accurate estimate, users must subtract the water removed at the Angostura Diversion Dam

The primary river gauge we monitor for the Bosque through Corrales (embedded below), is USGS 08329928 RIO GRANDE NR ALAMEDA, NM. This is the second gauge downstream of the reach we operate on, and users should add about 75-100 cfs to the reading  to account for water that is diverted at the San Juan/Cham diversion dam immediately upstream.

We previously monitored the Alameda Bridge gauge (above the diversion), but regular malfunctions at that site renders it unreliable. We continue to monitor the Alameda Bridge site for water temperatures, and that information can be found on our Cooler Weather Paddling page.

The graph updates every fifteen minutes, so what you're seeing is basically in “real time”. Clicking the link below the embedded graph will open a new window, taking you to the USGS page with full data for the gauge:

Bosque Flow Conditions (Corrales Siphon to Alameda)

USGS Water-data graph for site 08329928

Link: USGS 08329928 RIO GRANDE NR ALAMEDA, NM (Opens in New Window)

Interpreting the Data

River flows are measured in cubic feet per second (cfs), and a cubic foot is approximately 7.5 gallons of water. To interpret the gauge, flows of 200 cfs (extremely low here) equates to 1500 gallons of water flowing past the gauge every second, or 90,000 gallons per minute. 1000 cfs equates to 7500 gallons per second, 2000 cfs to 15,000 gallons per second, and so on.

Obviously, higher flows means deeper water, and since opening in early 2010 we've witnessed both record highs and lows, ranging from as little as 150 cfs, to over 6000 cfs. Higher flows simply means more depth, lower flows means less depth. Higher flows also means faster current speeds and increased severity of hazards that are present.

Every time we've seen a new low or high, we've ventured out to discover what effect varying flows have on recreation. We'll continue to do so as time goes on, but what follows is a dose of reality as to what to expect over a very wide range. Although New Mexico's extended drought certainly stressed the Rio Grande and its wildlife as flows declined, if there's a silver lining for paddlers, it's that we're yet to reach levels where the river is no longer navigable by paddlecraft. If it declines beyond the ranges shown above, we'll explore it again, and continue to do so until we arrive at a low limit, at which point we'll suspend operations until sufficient flows resume. It is highly unlikely that we'll reach that point however, as environmental and pueblo requirements virtually ensure sufficient flows for paddlers north of Albuquerque.

Disclaimer:This information is provided as an educational and informational guide only. All rivers can change dramatically with variations in flow, and the Middle Rio Grande is no exception. High flows can and do create countless unknown hazards, including collapsing trees and riverbanks, large floating debris, increased current speeds and challenging sections for inexperienced paddlers. Those with little experience should not rely on the following in any way, and we provide no warranties, assurances of safety or security, nor any other guarantees of any kind regarding any decisions made by any person or persons with regard to any use of the information provided below.

Expanded Class I/Class I+ River Classifications

(Courtesy of Ron Watters, Idaho State University)

The river classification system developed by American Whitewater is an excellent system for whitewater boaters, but fails to adequately address the wide variations involved in “Class I” water the casual recreational paddler may encounter.

 

Ron Watters of Idaho State University recognized this issue in a 1999 paper which presented a proposal to expand and more clearly define variations that can and do exist on Class I rivers. These definitions are highly applicable to the Middle Rio Grande, so we've chosen to adopt, share and apply them below. The full paper, which includes Professor Watters' recommendations for families, can be accessed by clicking the header above.

 

Class I (1.0) Flat, lake-like water. No current or very slow moving current. One can easily paddle upstream and downstream. . . . Since the water is slow moving, downriver trips against strong winds, may be taxing. . . . Inflatable boaters may find this water sluggish, requiring a lot of paddling to get downstream. (Some boaters might call this type of water class I- on the international scale.)

 

Class I (1.1) Flat water with some current. One can paddle upstream, but it takes more effort. Since it has current, it may have some minor eddies. . . . (Easy class I water.)

 

Class I (1.2) Flat water with current, minor riffles and some eddies. Paddling upstream is possible in some places, but in other places it may be very difficult or not possible at all. These rivers may have some overhanging trees and brush. . . . (Moderately easy class I.)

 

Class I+ (1.3) Moving water with mini-rapids. Small, mini-rapids may occur in swift areas of the river-or where the river slides down gravel bars. The river may have some swift corners with overhanging trees on the outside of bends. Rocks and boulders may be present which need to be avoided, but the current is gentle and not strong enough to cause a boat to get wrapped or broached.

Basic maneuvering skills are needed, including the ability to move to the right or left and avoid the outside of bends, and the ability to miss an occasional rock. Boaters should know the basics of an eddy turn and how to use an eddy to stop, as well as understanding the preliminaries of reading water. . . . (This is the beginning of class I+ water.)

 

Class I+ (1.4) Swift water with mini-rapids, small waves and obstructions. The river may bend sharply and the current on the outside of bends is more forceful. Such rivers may have narrow channels with long stretches of overhanging trees and brush in which a boat can get hung up and flipped over.

Canoeists and kayakers should have a good understanding of how to lean boats while in the current, or while turning in and out of eddies, or if accidentally pushed up against an obstruction. Boaters should be very comfortable maneuvering the boat through rocks and have the ability to catch small eddies. A sureness of technique is needed to stop quickly if fences, trees or diversions are encountered. . . . Note that some inflatable kayaks may be too sluggish to handle the type of maneuvering needed for this type of river. (This is difficult class I water, well into the class I+ range.)

 

Class I+ (1.5) Rapid water with small rapids, waves and obstructions. The river may be very narrow and have many sharp turns and long stretches of overhanging trees and brush. In higher flows, trees, log jams and other strainers are dangerous.

Some waves may be present which, if run sideways, can swamp a canoe. Improper leans in a canoe or kayak can cause a capsize. Boaters must have the ability to read the water, anticipate future moves and react quickly. A well-practiced, reliable eddy turn is a must.

 

Application of the Expanded Class I/Class I+ Rating System

Below 300 cfs

The Coronado (Algodones to North Corrales): Class I (1.3) to Class I+ (1.5) (Requires very good shallow water river reading skills and boat control)

The Bosque (North Corrales to Alameda): Class I (1.0) to Class I (1.3), with exceptional shallow water river reading skills required.

 

At levels below 300, the river channel constricts, requiring very good shallow water river reading skills to identify the channel, as well as good boat control to avoid assorted hazards – sweepers, strainers, log jams, etc. - that tend to concentrate in close proximity to the deep channel. The two small rapids in the Coronado reach become very rocky and active (but passable), while the second rapid transforms to technically a Class II due to several large exposed large rocks at the final drop.

Flows dropped to 174 cfs on June 18, 2022. and the deep channel ranged from well over 3' in some areas, to less than a foot of depth in others. Based on this, we expect that the Coronado reach will remain entertaining for experienced river runners to significantly below this level, but the less experienced should anticipate occasional grounding and must exercise care due to the various hazards.

We have not scouted the Bosque section recently, but suspect that the last two miles approaching Alameda will be extremely challenging.

 

300 – 800 cfs

The Coronado (Algodones to North Corrales): Class I (1.2) to Class I+ (1.3)

The Bosque (North Corrales to Alameda): Class I (1.0) to Class I (1.2), with excellent shallow water river reading skills required

 

Deep channel ranges from one to three feet in depth. Numerous sand and gravel bars are exposed, creating many small features of cascading water. Simple river-reading skills are helpful. Algodones to Corrales (“The Coronado”) is navigable, but the constricted channel leads to numerous close encounters with sweepers, strainers and other hazards that require excellent boat control to avoid. Small rapids are shallow, rocky and active. Last two miles of Corrales to Alameda (“The Bosque”) very challenging due to wider, braided channel and requires exceptional shallow water river reading skills. Recent sediment deposits near the Alameda bridge will almost definitely require a portage of several hundred feet to reach the Corrales takeout. The entire reach is Class I at these flows, with current speeds ranging from 2 to 5 miles per hour, but hazards do exist – sweepers, strainers and occasional obstructions are present at all flows.“The Bosque” section a little easier with the additional depth, but still requires excellent shallow water river reading skills. Still Class I water, similar current speeds as above, but slightly more depth and width brings some additional hazards into play.

 

800 – 1200 cfs

The Coronado (Algodones to North Corrales): Class I (1.2) to Class I+ (1.5)

The Bosque (North Corrales to Alameda): Class I (1.0) to Class I+ (1.3), with some shallow water river reading skills required.

 

A fairly common flow range in normal precipitation years, the deep channel ranges from 18” - 4 ½'. “The Bosque” reach becomes significantly easier above 800 cfs, but good river reading skills are still required, especially over the last two miles. Class I most of the way, but sections of Class I+ as current speeds climb to 3 – 6 mph at the upper end of this range, and hazards, especially those on the outside of some meander bends, require good boat control to avoid.

 

1200 – 2000 cfs

The Coronado (Algodones to North Corrales): Class I+ (1.3) to Class II

The Bosque (North Corrales to Alameda): Class I (1.0) to Class I+ (1.3)

 

Deep channel rarely less that 2'. Mostly Class I/I+ water, with short Class II sections that present few problems for trained paddlers but can be challenging for the inexperienced. Current quickens slightly (3 – 7 mph), and some secondary channels begin to fill. Small rapids begin to level out as flows elevate. Class I/II conditions and the additional width of the river channel brings numerous low hanging trees into play near shore.

 

2000 – 3500 cfs

The Coronado (Algodones to North Corrales): Class I+ (1.4) to Class II

The Bosque (North Corrales to Alameda): Class I (1.1) to Class I+ (1.4)

 

Common spring flow conditions in normal snowpack years, and occasionally seen following summer monsoon storms. Deep channel ranges from 3' – 7'. Numerous secondary channels begin to fill – many are navigable above 2500 cfs. Class I/II with current speeds of 4 – 8 mph, tree branches and other irregular debris is often observed floating downstream. The increased width and faster current resulting from higher flows brings low hanging trees near shore into play nearly continually in numerous sections, and obstructions in the river channel begin to be submerged, creating additional hazards for those unfamiliar with reading rivers..

 

Above 3500 cfs

The Coronado (Algodones to North Corrales): Class I+ (1.4) to Class II

The Bosque (North Corrales to Alameda): Class I (1.2) to Class I+ (1.5)

 

Deep channel rarely less than 5' in depth. All secondary channels are flowing, most are navigable, but may contain unknown hazards (downed trees and other obstructions). Class I+/II, and current is noticeably quicker, rarely less than 5 mph most of the way – tour times are significantly reduced. Large floating debris (even entire trees) may be present. Flows at these levels are relatively rare – usually a couple of weeks of peak spring flows in good runoff years, and occasionally seen following especially heavy monsoon downpours.