Communal Bath for Robins

Flocks of robins have been appreciating the backyard minipond the last couple days, arriving in flocks of 20 or so to splash in the shallow water. Their frenzied head-dipping is reminiscent of the movement of the birds on this toy, and wooden birds are much more cooperative in front of a camera.

While half of the flock is in the water, the other half remains perched in the overhanging branches, to keep a keen eye or two out for any approaching photographers. The old apple tree next to the pond, half of its branches dead, serves this function well. The human inclination is to trim trees up and remove all the dead branches, but the birds make it clear they like lots of perches of varied heights--the better to scope out the ground before dropping in.

Princeton High School Floods Again

Yesterday, with Hurricane Irene headed our way, I stopped by the Princeton High School to check on preparations for the coming deluge. This part of the school had stormwater seep under the doors a week ago, and was most emphatically flooded two years prior when Hurricane Bill paid a visit. I've heard from several sources that the bill for Hurricane Bill included a new stage floor for the high school's performing arts center, which had become warped by flooding damage. Even if insurance paid for the replacement, one has to wonder if the district school's insurance rates took a jump afterwards.

Here's how the flooding happens: The retention basin in the photo (a.k.a. "ecolab", which we have planted with native wetland species), is surrounded on three sides by the high school and receives runoff from the high school roofs and also from nearby parking lots. The basin in turn drains into the system of stormwater pipes underneath Walnut Street. If it rains long enough and hard enough, however, the street's underground stormdrain system becomes filled to the brim, water has nowhere to go, and the basin overflows. At that point, pipes no longer matter and surface flow dictates where floodwater goes. Since water flows downhill, the only way to get rid of the water is for it to flow out to Walnut Street and safely away from the building. Unfortunately, Walnut Street is higher than the high school doorway thresholds. In these heavy rains, Walnut Street floods and becomes a river, and stormwater actually flows towards the high school rather than away.

The highschool has responded to this by placing sandbags in front of all the doorways during heavy rains. These help, but when I stopped by at 1am this morning, after Irene's fury had begun to ease, the music room and hallway into the performing arts center showed signs of having again been flooded. (These photos were taken this morning, after stormwater had receded.)

Exasperated school staff were trying to pump water out of the school. The custodians had just finished prepping all the floors for the return of students, and now they would have to do it all over again. The cafeteria had flooded, and it looked like utility rooms in the basement were now under water.

One staff member tried to blame the vegetation in the retention basin, but all around him was evidence that the vegetation had played no role in the flooding whatsoever.

 

The drain, photographed this morning, showed no signs of blockage, which is no surprise given that, when the street storm drains become overwhelmed, the water reverses flow and heads in to the retention basin from the street, rather than out.

At 1am this morning, this whole area was a lake.

A curb cut meant to carry surface water away from the retention basin was instead carrying water towards it.

The only solution I see is to lower the curb on the other side of Walnut Street so that the mighty Walnut Street River can flow into the field owned by Westminster Conservatory.

This, in fact, is what some water was doing last night, but to an insufficient extent.

A pond formed in this field last night, next to the Westminster parking lot. Last year, the field was declared by Westminster's own consultants to be a wetland that could not be developed. Since the conservatory uses the highschool performing arts center for some of its performances, utilizing this field more effectively to prevent flooding of the high school seems to be a solution that would benefit all involved.






What needs to be made clear to decision-makers is that the native plantings in the retention basin have no impact on flooding, lest this ecologically vibrant and educational planting become the victim of an invasion of red herring.

Kayaking Through A Wetland Garden--the Lehigh River and Glen Onoko Falls

Say you love to whitewater canoe, and want your kids to experience the same joys of running rapids that you remember from childhood. But you live in New Jersey. Chances are, your internet research will lead you beyond the Delaware River to the Poconos, which turn out to be in Pennsylvania. As it happened, they were right on the way to a family gathering we were having at ancestral grounds further west.

Rentable canoes for whitewater apparently no longer exist, but Blue Mountain Sports offers a ten mile do-it-yourself kayak trip through some easier rapids on the Lehigh River, starting at the town of Jim Thorpe.

The rapids were a perfect introduction for my daughter, who quickly figured out how to follow the current and steer clear of the rocks.

Meanwhile, Dad was getting distracted by the native plant diversity flourishing along river's edge. Conducting plant inventories while negotiating rapids may prove to be the next new fad in extreme botany. Cardinal flower (red) and JoePyeWeed (pink) grew thick along the shore, mixed with a host of other familiar native species that sometimes made me feel like I was kayaking through my backyard.

One surprise was the streamside stands of big bluestem, a tall native grass more typical of midwestern prairies. It's also called turkey foot, for the 3-pronged seedheads it sticks up into the air like an upside down turkey. (Other species seen as the current pulled us along: river birch, red maple, alder, spiraea, buttonbush, deciduous holly, buckthorn (hopefully the native Rhamnus lanceolata), meadow rue, fringed loosestrife, cutleaf coneflower, and what looked like a native hosta.)

Causing some worry were a few sightings of Japanese knotweed, an exotic species that can replace native diversity with a monoculture over time.

Here, a cardinal flower is trying to hold on at the edge of an expanding Japanese knotweed clone. A several-acre field of solid J. knotweed seen on the way in to Jim Thorpe foretells what could happen to this beautiful river corridor if no preemptive action is taken to nip knotweed's invasion in the bud.

Later on, camping at Mauch Chunk State Park, the lakeshore offered still more familiar wetland garden species. Here's deer tongue grass, which in Princeton is numerous along the towpath.

Pickerelweed blooms all summer long just out from the shoreline, thriving in the stable water regime of the park's impoundment.

The next day, after making a note to research better pads for sleeping in a tent, it was back to the Lehigh River for a hike up a narrow valley to the Glen Onoko Falls.

The trail is unmaintained, and described as steep and dangerous. On a dry day, and exercising some care, the hike was easily doable. We had almost as much fun going up as the water clearly was having cascading down the hillside.

For a picnic at the top, the view provides the main sustenance.

Flood Alert--Basement Recall

Heavy rains in late August can cause major mischief in Princeton, with many people gone on vacation and a lot of basements left unwatched. This is a good time to recall someone who's out of town, and consider contacting them to ask if their basement is prone to flooding. Typically, the worst flooding happens during the last of a series of downpours, after the ground has already become saturated from previous rains.

For my part, as the last downpour was easing up at dusk, I headed out across flooded streets to the high school ecolab wetland, where past overwhelmings of the stormdrains had caused water on Walnut Street to flow under the back doorway into the performing arts center, ruining the stage floor. Since that fiasco, the school has sandbagged the doorway during heavy rains. But in late August, it's quite possible that the staff who know about the sandbagging procedure are on vacation.

 

The first evidence of heavy flooding was a green frog playing the role of refugee from its own wetland,

which was filled to the brim with water from nearby roofs, parking lots and streets. It's supposed to fill up like that; the design flaw is in the overflow, which sends extra water not out into the street but instead towards the school. The hallway of the performing arts center looked a little wet. I slogged home, called the borough police and asked them to have someone at the school check for flooding indoors.

Of course, it would be nice if product recalls could include flood-prone buildings and basements. Simply send them all back to the original builders for a redesigned version.

Early Summer Wildflowers

A nice native combination this time of year is black-eyed susan in front of bottlebrush grass. These, along with cutleaf coneflower, tall meadow rue, wild senna and other local natives, I included in a miniature raingarden planting along the sidewalk at Whole Earth Center on Nassau Street.

Some white flowers to keep an eye out for are bottlebrush buckeye (in front of Mountain Lakes House),

buttonbush (along the edge of Carnegie Lake and the canal),

and Lizard's Tail (also found along the edge of Carnegie Lake).

A Manmade Wildlife Sanctuary on Walnut Street

 One of my favorite spots to stop on a summer evening is the ecolab wetland at Princeton High School. Most detention basins are mowed, making for curious grass pits of little use for wildlife, but this one we managed to transform into a glorious display of native plants, teaming with frogs, crayfish and birds.

The basin was designed to receive water from the highschool's roofs and a parking lot or two, but the unusual plant diversity is sustained by the high school's sump pump. "Old Faithful", I call it, because it pumps water from the basement year round, every fifteen minutes or so.

The biggest threat to the wetland, other than loss of that wonderfully consistent water source, may come as a surprise. The weeded out plant debris in the foreground of the photo is cattail, which is the native plant people most commonly associate with wetlands. Yet, it is so aggressive that, if we were to allow it to grow here, it would soon dominate to the exclusion of 20 or 30 other native species.

Liking cattails, we allow them to grow in one corner,

and also planted a less aggressive species of cattail--narrow-leaved cattail, which is also native but rarely encountered in the wild.

Stop by sometime when you're on Walnut Street, on the back side of the school. It can be fun to watch the goldfinches and sparrows bomb around, ducking into the cover of a willow, eating seeds, feeding their fledglings and singing their proud songs atop last year's dried stalks of hibiscus.

Spring Cleaning in the Raingarden

 One of the easiest and most rewarding spring tasks is preparing a raingarden for a new season of growth. This raingarden was installed by Curtis Helm and me at Princeton borough's Senior Resource Center on Harrison Street. Water from the roofs is channeled into the garden, where it accumulates to several inches in the hollowed out area and then slowly seeps into the ground. Mosquitoes are not an issue because the water does not stand long enough for them to breed. A list of the plants, all adapted to wet soils, can be found in another post.

All that was needed was a pair of pruning shears, gloves, and a plastic grocery bag that was conveniently found amongst all the paper and plastic trash caught by the raingarden over the winter.  

 Though the spring cleaning of a raingarden is easy and rewarding, I nonetheless postponed it until the last minute. One more week and the new growth would have become tangled in last year's dead stalks.

First step was to cut the brown stems of joepyeweed, green bulrush and other native perennials.

 It's important to check the downspouts that conduct water to the garden,

one of which had lost its underlying stones and needed a little tightening of the joints.

Pulling the occasional weed like false strawberry (Duchesnia indica, also called Indian strawberry, because it is native to India),

and gill-over-the-ground ( Glechoma hederacea, also called creeping charlie, or ground ivy) is a piece of cake if the soil is still soft after recent rains. 

Garlic mustard is a common weed that will spread by seed if not pulled out before it flowers. I've heard it makes good pesto, but have never tried it out.

 All that was left was to pick up the trash and toss the stalks back in the woods. No need to burden the borough crews with yardwaste that can easily decompose unnoticed back near a fenceline.

Less than an hour and it was done. Now to figure out how to make a raingarden grow cake.

H2O's Backyard Residency

Today, before spring takes over, a reach back into winter to offer up a pictorial paean to the most creative molecule on earth, H2O, which here uses the minipond in the backyard to craft its endless permutations of beauty.

One day the pond looks like this, with a curious granular form of snow fallen on dark ice.

The next brings melting and reconfiguring into new hues and patterns.

The variety in the patterns owes in part to the underlying clay, which by absorbing the water very slowly causes the ice to drop gracefully in terraces.

Air gets trapped underneath, changing its shape minute

to minute.

In the paved world out the front door, snow, sleet and ice are a burden to be grappled with, but around back, where there's no pavement to be kept clean, no place that needs to be gone to, water in all its forms acts as artist in residence, conducting workshops on wizardry in the backyard pond.

Two Talks Tonight

As mentioned prior, a butterfly talk at DR Greenway tonight, with the actual talk beginning at 7pm. Meanwhile, a talk on raingardens that I just found out about will begin at 7:30 at the library tonight. The raingarden talk is by Curtis Helm, a former Princeton resident whom I helped to install the raingarden on Harrison Street (click here to see previous posts about the raingarden). Both talks should be great. I'm going to try my best to be at two places at once. Info from respective websites below:

Family-Friendly Butterfly Talk
Thursday, March 10, 6:30 – 8:30 p.m.
Award-winning author and butterfly expert Rick Mikula will teach us how
butterflies interact with the plants in the meadows and grasslands that sustain
them. Rick will provide guidance about how everyone can play a vital role
in ensuring that these habitats meet the nutrition, shelter, and connectivity
needs to support a butterfly population that will continue to give us beautiful
delights for all the senses.
The program will be held at DR Greenway's Johnson Education Center, One Preservation Place, Princeton. All programs are open to the public, and registration is helpful by calling 609.924.4646


7:30 p.m. Princeton Public Library

Talk: Rain Gardens

The rainwater that runs off of roofs, roads, driveways and sidewalks carries pesticides, fertilizers, oil and sediments into the nearest storm drain. The next stop is the nearest stream or river, and this contributes to pollution, flooding and erosion. A rain garden captures and filters the rainwater before it can runoff to the nearest storm drain. This reduces flooding and pollution, and provides a  wildlife habitat. Curtis Helm, Project Coordinator, Urban Forestry and Ecosystem Management of Philadelphia's Department of Parks and Recreation presentation, will talk about basic principles and methods for constructing a rain garden of your own. Community Room

                                                 

Plant Rescue at Mountain Lakes

Now, that's strange. Seems to me there was a lake around here somewhere. The plug has been pulled, the 7 feet of fertile sediment accumulated over the past 100 years is being dug and hauled off to farms and topsoil makers, and the dam is being restored to its cerca 1900 appearance. Given the highly conducive weather thus far, the contractor is hoping to complete restoration of the upper lake and dam by December.

One of the streams that feeds the lakes enters back where the trees meet the mud in this photo, between the two backhoes. From an old aerial photo the engineers determined that the pond used to extend further up into that valley, and I was alerted that some more mud and associated plants would be coming out.

FOPOS board member Tim Patrick-Miller agreed to help me rescue some of the wetland species before the digging started. Much to my surprise, we found 4 species to add to the list of plants growing at Mountain Lakes.

In the wheelbarrow (our manual labors contrasted comically with the big machinery of the dredging operation) is pickerel weed, which is rarely found growing in the wild in Princeton. It likes shallow standing water at pond's edge.

Nearby was a little gravel streambed, away from the main current, that was clearly perfect habitat for three other species of plants also rarely encountered. This one, new to me, turned out to be ditch stonecrop. Not a pretty name, but it's true it was growing in something akin to a stony ditch.

Water plantain has oval leaves and tiny white flowers. It also needs a very stable hydrology, quickly perishing for lack of water.

Petals and branchings come in threes.

Bur Reed has leaves like an iris and seed capsules like those that fall from a sweet gum tree.

All four of these species only survive in locations that stay consistently wet throughout the summer. Though this continent once had abundant wetlands with much more stable hydrology, suggesting these plants were once abundant, the only places I find them now are in areas kept artificially wet, such as the edges of impoundments like Mountain Lakes, and the pump-enhanced marsh at Rogers Refuge.